v5:
- add more reviews (thank you!)
- add "description" string to post_load_data API (mimi)
- drop bug fix that got taken already
v4: https://lore.kernel.org/lkml/[email protected]/
v3: https://lore.kernel.org/lkml/[email protected]/
v2: lost to the ether
v1: https://lore.kernel.org/lkml/[email protected]/
Hi,
Here's my tree for adding partial read support in kernel_read_file(),
which fixes a number of issues along the way. It's got Scott's firmware
and IMA patches ported and everything tests cleanly for me (even with
CONFIG_IMA_APPRAISE=y), and now appears to pass 0day. :)
The intention is for this to go via Greg's tree since Scott's driver
code will depend on it.
Thanks,
-Kees
Kees Cook (12):
fs/kernel_read_file: Remove FIRMWARE_PREALLOC_BUFFER enum
fs/kernel_read_file: Remove FIRMWARE_EFI_EMBEDDED enum
fs/kernel_read_file: Split into separate source file
fs/kernel_read_file: Remove redundant size argument
fs/kernel_read_file: Switch buffer size arg to size_t
fs/kernel_read_file: Add file_size output argument
LSM: Introduce kernel_post_load_data() hook
firmware_loader: Use security_post_load_data()
module: Call security_kernel_post_load_data()
LSM: Add "contents" flag to kernel_read_file hook
fs/kernel_file_read: Add "offset" arg for partial reads
firmware: Store opt_flags in fw_priv
Scott Branden (4):
fs/kernel_read_file: Split into separate include file
IMA: Add support for file reads without contents
firmware: Add request_partial_firmware_into_buf()
test_firmware: Test partial read support
drivers/base/firmware_loader/fallback.c | 19 +-
drivers/base/firmware_loader/fallback.h | 5 +-
.../base/firmware_loader/fallback_platform.c | 12 +-
drivers/base/firmware_loader/firmware.h | 7 +-
drivers/base/firmware_loader/main.c | 135 ++++++++++---
fs/Makefile | 3 +-
fs/exec.c | 132 +-----------
fs/kernel_read_file.c | 189 ++++++++++++++++++
include/linux/firmware.h | 12 ++
include/linux/fs.h | 39 ----
include/linux/ima.h | 20 +-
include/linux/kernel_read_file.h | 55 +++++
include/linux/lsm_hook_defs.h | 6 +-
include/linux/lsm_hooks.h | 13 ++
include/linux/security.h | 21 +-
kernel/kexec.c | 2 +-
kernel/kexec_file.c | 19 +-
kernel/module.c | 24 ++-
lib/test_firmware.c | 154 ++++++++++++--
security/integrity/digsig.c | 8 +-
security/integrity/ima/ima_fs.c | 10 +-
security/integrity/ima/ima_main.c | 73 +++++--
security/integrity/ima/ima_policy.c | 1 +
security/loadpin/loadpin.c | 17 +-
security/security.c | 28 ++-
security/selinux/hooks.c | 8 +-
.../selftests/firmware/fw_filesystem.sh | 91 +++++++++
27 files changed, 807 insertions(+), 296 deletions(-)
create mode 100644 fs/kernel_read_file.c
create mode 100644 include/linux/kernel_read_file.h
--
2.25.1
These routines are used in places outside of exec(2), so in preparation
for refactoring them, move them into a separate source file,
fs/kernel_read_file.c.
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Acked-by: Scott Branden <[email protected]>
---
fs/Makefile | 3 +-
fs/exec.c | 132 ----------------------------------------
fs/kernel_read_file.c | 138 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 140 insertions(+), 133 deletions(-)
create mode 100644 fs/kernel_read_file.c
diff --git a/fs/Makefile b/fs/Makefile
index 1c7b0e3f6daa..40c19ff3d570 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -13,7 +13,8 @@ obj-y := open.o read_write.o file_table.o super.o \
seq_file.o xattr.o libfs.o fs-writeback.o \
pnode.o splice.o sync.o utimes.o d_path.o \
stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
- fs_types.o fs_context.o fs_parser.o fsopen.o init.o
+ fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
+ kernel_read_file.o
ifeq ($(CONFIG_BLOCK),y)
obj-y += buffer.o block_dev.o direct-io.o mpage.o
diff --git a/fs/exec.c b/fs/exec.c
index c454af329413..9f094406ea82 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -950,138 +950,6 @@ struct file *open_exec(const char *name)
}
EXPORT_SYMBOL(open_exec);
-int kernel_read_file(struct file *file, void **buf, loff_t *size,
- loff_t max_size, enum kernel_read_file_id id)
-{
- loff_t i_size, pos;
- ssize_t bytes = 0;
- void *allocated = NULL;
- int ret;
-
- if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0)
- return -EINVAL;
-
- ret = deny_write_access(file);
- if (ret)
- return ret;
-
- ret = security_kernel_read_file(file, id);
- if (ret)
- goto out;
-
- i_size = i_size_read(file_inode(file));
- if (i_size <= 0) {
- ret = -EINVAL;
- goto out;
- }
- if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) {
- ret = -EFBIG;
- goto out;
- }
-
- if (!*buf)
- *buf = allocated = vmalloc(i_size);
- if (!*buf) {
- ret = -ENOMEM;
- goto out;
- }
-
- pos = 0;
- while (pos < i_size) {
- bytes = kernel_read(file, *buf + pos, i_size - pos, &pos);
- if (bytes < 0) {
- ret = bytes;
- goto out_free;
- }
-
- if (bytes == 0)
- break;
- }
-
- if (pos != i_size) {
- ret = -EIO;
- goto out_free;
- }
-
- ret = security_kernel_post_read_file(file, *buf, i_size, id);
- if (!ret)
- *size = pos;
-
-out_free:
- if (ret < 0) {
- if (allocated) {
- vfree(*buf);
- *buf = NULL;
- }
- }
-
-out:
- allow_write_access(file);
- return ret;
-}
-EXPORT_SYMBOL_GPL(kernel_read_file);
-
-int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
- loff_t max_size, enum kernel_read_file_id id)
-{
- struct file *file;
- int ret;
-
- if (!path || !*path)
- return -EINVAL;
-
- file = filp_open(path, O_RDONLY, 0);
- if (IS_ERR(file))
- return PTR_ERR(file);
-
- ret = kernel_read_file(file, buf, size, max_size, id);
- fput(file);
- return ret;
-}
-EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
-
-int kernel_read_file_from_path_initns(const char *path, void **buf,
- loff_t *size, loff_t max_size,
- enum kernel_read_file_id id)
-{
- struct file *file;
- struct path root;
- int ret;
-
- if (!path || !*path)
- return -EINVAL;
-
- task_lock(&init_task);
- get_fs_root(init_task.fs, &root);
- task_unlock(&init_task);
-
- file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0);
- path_put(&root);
- if (IS_ERR(file))
- return PTR_ERR(file);
-
- ret = kernel_read_file(file, buf, size, max_size, id);
- fput(file);
- return ret;
-}
-EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
-
-int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
- enum kernel_read_file_id id)
-{
- struct fd f = fdget(fd);
- int ret = -EBADF;
-
- if (!f.file)
- goto out;
-
- ret = kernel_read_file(f.file, buf, size, max_size, id);
-out:
- fdput(f);
- return ret;
-}
-EXPORT_SYMBOL_GPL(kernel_read_file_from_fd);
-
#if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \
defined(CONFIG_BINFMT_ELF_FDPIC)
ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
new file mode 100644
index 000000000000..54d972d4befc
--- /dev/null
+++ b/fs/kernel_read_file.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/fs.h>
+#include <linux/fs_struct.h>
+#include <linux/kernel_read_file.h>
+#include <linux/security.h>
+#include <linux/vmalloc.h>
+
+int kernel_read_file(struct file *file, void **buf, loff_t *size,
+ loff_t max_size, enum kernel_read_file_id id)
+{
+ loff_t i_size, pos;
+ ssize_t bytes = 0;
+ void *allocated = NULL;
+ int ret;
+
+ if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0)
+ return -EINVAL;
+
+ ret = deny_write_access(file);
+ if (ret)
+ return ret;
+
+ ret = security_kernel_read_file(file, id);
+ if (ret)
+ goto out;
+
+ i_size = i_size_read(file_inode(file));
+ if (i_size <= 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) {
+ ret = -EFBIG;
+ goto out;
+ }
+
+ if (!*buf)
+ *buf = allocated = vmalloc(i_size);
+ if (!*buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ pos = 0;
+ while (pos < i_size) {
+ bytes = kernel_read(file, *buf + pos, i_size - pos, &pos);
+ if (bytes < 0) {
+ ret = bytes;
+ goto out_free;
+ }
+
+ if (bytes == 0)
+ break;
+ }
+
+ if (pos != i_size) {
+ ret = -EIO;
+ goto out_free;
+ }
+
+ ret = security_kernel_post_read_file(file, *buf, i_size, id);
+ if (!ret)
+ *size = pos;
+
+out_free:
+ if (ret < 0) {
+ if (allocated) {
+ vfree(*buf);
+ *buf = NULL;
+ }
+ }
+
+out:
+ allow_write_access(file);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kernel_read_file);
+
+int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
+ loff_t max_size, enum kernel_read_file_id id)
+{
+ struct file *file;
+ int ret;
+
+ if (!path || !*path)
+ return -EINVAL;
+
+ file = filp_open(path, O_RDONLY, 0);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+
+ ret = kernel_read_file(file, buf, size, max_size, id);
+ fput(file);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
+
+int kernel_read_file_from_path_initns(const char *path, void **buf,
+ loff_t *size, loff_t max_size,
+ enum kernel_read_file_id id)
+{
+ struct file *file;
+ struct path root;
+ int ret;
+
+ if (!path || !*path)
+ return -EINVAL;
+
+ task_lock(&init_task);
+ get_fs_root(init_task.fs, &root);
+ task_unlock(&init_task);
+
+ file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0);
+ path_put(&root);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+
+ ret = kernel_read_file(file, buf, size, max_size, id);
+ fput(file);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
+
+int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
+ enum kernel_read_file_id id)
+{
+ struct fd f = fdget(fd);
+ int ret = -EBADF;
+
+ if (!f.file)
+ goto out;
+
+ ret = kernel_read_file(f.file, buf, size, max_size, id);
+out:
+ fdput(f);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kernel_read_file_from_fd);
--
2.25.1
As with the kernel_load_data LSM hook, add a "contents" flag to the
kernel_read_file LSM hook that indicates whether the LSM can expect
a matching call to the kernel_post_read_file LSM hook with the full
contents of the file. With the coming addition of partial file read
support for kernel_read_file*() API, the LSM will no longer be able
to always see the entire contents of a file during the read calls.
For cases where the LSM must read examine the complete file contents,
it will need to do so on its own every time the kernel_read_file
hook is called with contents=false (or reject such cases). Adjust all
existing LSMs to retain existing behavior.
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
---
fs/kernel_read_file.c | 2 +-
include/linux/ima.h | 6 ++++--
include/linux/lsm_hook_defs.h | 2 +-
include/linux/lsm_hooks.h | 3 +++
include/linux/security.h | 6 ++++--
security/integrity/ima/ima_main.c | 10 +++++++++-
security/loadpin/loadpin.c | 14 ++++++++++++--
security/security.c | 7 ++++---
security/selinux/hooks.c | 5 +++--
9 files changed, 41 insertions(+), 14 deletions(-)
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index 2e29c38eb4df..d73bc3fa710a 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -39,7 +39,7 @@ int kernel_read_file(struct file *file, void **buf,
if (ret)
return ret;
- ret = security_kernel_read_file(file, id);
+ ret = security_kernel_read_file(file, id, true);
if (ret)
goto out;
diff --git a/include/linux/ima.h b/include/linux/ima.h
index af9fb8c5f16a..8fa7bcfb2da2 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -23,7 +23,8 @@ extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot);
extern int ima_load_data(enum kernel_load_data_id id, bool contents);
extern int ima_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id id, char *description);
-extern int ima_read_file(struct file *file, enum kernel_read_file_id id);
+extern int ima_read_file(struct file *file, enum kernel_read_file_id id,
+ bool contents);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
extern void ima_post_path_mknod(struct dentry *dentry);
@@ -92,7 +93,8 @@ static inline int ima_post_load_data(char *buf, loff_t size,
return 0;
}
-static inline int ima_read_file(struct file *file, enum kernel_read_file_id id)
+static inline int ima_read_file(struct file *file, enum kernel_read_file_id id,
+ bool contents)
{
return 0;
}
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 83c6f1f5cc1e..d67cb3502310 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -188,7 +188,7 @@ LSM_HOOK(int, 0, kernel_load_data, enum kernel_load_data_id id, bool contents)
LSM_HOOK(int, 0, kernel_post_load_data, char *buf, loff_t size,
enum kernel_read_file_id id, char *description)
LSM_HOOK(int, 0, kernel_read_file, struct file *file,
- enum kernel_read_file_id id)
+ enum kernel_read_file_id id, bool contents)
LSM_HOOK(int, 0, kernel_post_read_file, struct file *file, char *buf,
loff_t size, enum kernel_read_file_id id)
LSM_HOOK(int, 0, task_fix_setuid, struct cred *new, const struct cred *old,
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 6bb4f1a0158c..8814e3d5952d 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -651,6 +651,7 @@
* @file contains the file structure pointing to the file being read
* by the kernel.
* @id kernel read file identifier
+ * @contents if a subsequent @kernel_post_read_file will be called.
* Return 0 if permission is granted.
* @kernel_post_read_file:
* Read a file specified by userspace.
@@ -659,6 +660,8 @@
* @buf pointer to buffer containing the file contents.
* @size length of the file contents.
* @id kernel read file identifier
+ * This must be paired with a prior @kernel_read_file call that had
+ * @contents set to true.
* Return 0 if permission is granted.
* @task_fix_setuid:
* Update the module's state after setting one or more of the user
diff --git a/include/linux/security.h b/include/linux/security.h
index 51c8e4e6b7cc..bc2725491560 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -391,7 +391,8 @@ int security_kernel_load_data(enum kernel_load_data_id id, bool contents);
int security_kernel_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id id,
char *description);
-int security_kernel_read_file(struct file *file, enum kernel_read_file_id id);
+int security_kernel_read_file(struct file *file, enum kernel_read_file_id id,
+ bool contents);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
int security_task_fix_setuid(struct cred *new, const struct cred *old,
@@ -1030,7 +1031,8 @@ static inline int security_kernel_post_load_data(char *buf, loff_t size,
}
static inline int security_kernel_read_file(struct file *file,
- enum kernel_read_file_id id)
+ enum kernel_read_file_id id,
+ bool contents)
{
return 0;
}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 6f2b8352573a..939f53d02627 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -602,6 +602,7 @@ void ima_post_path_mknod(struct dentry *dentry)
* ima_read_file - pre-measure/appraise hook decision based on policy
* @file: pointer to the file to be measured/appraised/audit
* @read_id: caller identifier
+ * @contents: whether a subsequent call will be made to ima_post_read_file()
*
* Permit reading a file based on policy. The policy rules are written
* in terms of the policy identifier. Appraising the integrity of
@@ -609,8 +610,15 @@ void ima_post_path_mknod(struct dentry *dentry)
*
* For permission return 0, otherwise return -EACCES.
*/
-int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
+int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
+ bool contents)
{
+ /* Reject all partial reads during appraisal. */
+ if (!contents) {
+ if (ima_appraise & IMA_APPRAISE_ENFORCE)
+ return -EACCES;
+ }
+
/*
* Do devices using pre-allocated memory run the risk of the
* firmware being accessible to the device prior to the completion
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index 28782412febb..b12f7d986b1e 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -118,11 +118,21 @@ static void loadpin_sb_free_security(struct super_block *mnt_sb)
}
}
-static int loadpin_read_file(struct file *file, enum kernel_read_file_id id)
+static int loadpin_read_file(struct file *file, enum kernel_read_file_id id,
+ bool contents)
{
struct super_block *load_root;
const char *origin = kernel_read_file_id_str(id);
+ /*
+ * If we will not know that we'll be seeing the full contents
+ * then we cannot trust a load will be complete and unchanged
+ * off disk. Treat all contents=false hooks as if there were
+ * no associated file struct.
+ */
+ if (!contents)
+ file = NULL;
+
/* If the file id is excluded, ignore the pinning. */
if ((unsigned int)id < ARRAY_SIZE(ignore_read_file_id) &&
ignore_read_file_id[id]) {
@@ -179,7 +189,7 @@ static int loadpin_read_file(struct file *file, enum kernel_read_file_id id)
static int loadpin_load_data(enum kernel_load_data_id id, bool contents)
{
- return loadpin_read_file(NULL, (enum kernel_read_file_id) id);
+ return loadpin_read_file(NULL, (enum kernel_read_file_id) id, contents);
}
static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
diff --git a/security/security.c b/security/security.c
index 531b855826fc..a28045dc9e7f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1672,14 +1672,15 @@ int security_kernel_module_request(char *kmod_name)
return integrity_kernel_module_request(kmod_name);
}
-int security_kernel_read_file(struct file *file, enum kernel_read_file_id id)
+int security_kernel_read_file(struct file *file, enum kernel_read_file_id id,
+ bool contents)
{
int ret;
- ret = call_int_hook(kernel_read_file, 0, file, id);
+ ret = call_int_hook(kernel_read_file, 0, file, id, contents);
if (ret)
return ret;
- return ima_read_file(file, id);
+ return ima_read_file(file, id, contents);
}
EXPORT_SYMBOL_GPL(security_kernel_read_file);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 558beee97d8d..dec654d52b68 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4003,13 +4003,14 @@ static int selinux_kernel_module_from_file(struct file *file)
}
static int selinux_kernel_read_file(struct file *file,
- enum kernel_read_file_id id)
+ enum kernel_read_file_id id,
+ bool contents)
{
int rc = 0;
switch (id) {
case READING_MODULE:
- rc = selinux_kernel_module_from_file(file);
+ rc = selinux_kernel_module_from_file(contents ? file : NULL);
break;
default:
break;
--
2.25.1
Instead of passing opt_flags around so much, store it in the private
structure so it can be examined by internals without needing to add more
arguments to functions.
Co-developed-by: Scott Branden <[email protected]>
Signed-off-by: Scott Branden <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
drivers/base/firmware_loader/fallback.c | 11 +++-----
drivers/base/firmware_loader/fallback.h | 5 ++--
.../base/firmware_loader/fallback_platform.c | 4 +--
drivers/base/firmware_loader/firmware.h | 3 ++-
drivers/base/firmware_loader/main.c | 25 +++++++++++--------
5 files changed, 25 insertions(+), 23 deletions(-)
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 251d92fc8bae..c4765461a951 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -490,13 +490,11 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
/**
* fw_load_sysfs_fallback() - load a firmware via the sysfs fallback mechanism
* @fw_sysfs: firmware sysfs information for the firmware to load
- * @opt_flags: flags of options, FW_OPT_*
* @timeout: timeout to wait for the load
*
* In charge of constructing a sysfs fallback interface for firmware loading.
**/
-static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs,
- u32 opt_flags, long timeout)
+static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs, long timeout)
{
int retval = 0;
struct device *f_dev = &fw_sysfs->dev;
@@ -518,7 +516,7 @@ static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs,
list_add(&fw_priv->pending_list, &pending_fw_head);
mutex_unlock(&fw_lock);
- if (opt_flags & FW_OPT_UEVENT) {
+ if (fw_priv->opt_flags & FW_OPT_UEVENT) {
fw_priv->need_uevent = true;
dev_set_uevent_suppress(f_dev, false);
dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_name);
@@ -580,10 +578,10 @@ static int fw_load_from_user_helper(struct firmware *firmware,
}
fw_sysfs->fw_priv = firmware->priv;
- ret = fw_load_sysfs_fallback(fw_sysfs, opt_flags, timeout);
+ ret = fw_load_sysfs_fallback(fw_sysfs, timeout);
if (!ret)
- ret = assign_fw(firmware, device, opt_flags);
+ ret = assign_fw(firmware, device);
out_unlock:
usermodehelper_read_unlock();
@@ -625,7 +623,6 @@ static bool fw_run_sysfs_fallback(u32 opt_flags)
* @fw: pointer to firmware image
* @name: name of firmware file to look for
* @device: device for which firmware is being loaded
- * @opt_flags: options to control firmware loading behaviour
* @ret: return value from direct lookup which triggered the fallback mechanism
*
* This function is called if direct lookup for the firmware failed, it enables
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
index 2afdb6adb23f..3af7205b302f 100644
--- a/drivers/base/firmware_loader/fallback.h
+++ b/drivers/base/firmware_loader/fallback.h
@@ -67,10 +67,9 @@ static inline void unregister_sysfs_loader(void)
#endif /* CONFIG_FW_LOADER_USER_HELPER */
#ifdef CONFIG_EFI_EMBEDDED_FIRMWARE
-int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags);
+int firmware_fallback_platform(struct fw_priv *fw_priv);
#else
-static inline int firmware_fallback_platform(struct fw_priv *fw_priv,
- u32 opt_flags)
+static inline int firmware_fallback_platform(struct fw_priv *fw_priv)
{
return -ENOENT;
}
diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c
index 8bdf88043079..00af99f0aff2 100644
--- a/drivers/base/firmware_loader/fallback_platform.c
+++ b/drivers/base/firmware_loader/fallback_platform.c
@@ -8,13 +8,13 @@
#include "fallback.h"
#include "firmware.h"
-int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
+int firmware_fallback_platform(struct fw_priv *fw_priv)
{
const u8 *data;
size_t size;
int rc;
- if (!(opt_flags & FW_OPT_FALLBACK_PLATFORM))
+ if (!(fw_priv->opt_flags & FW_OPT_FALLBACK_PLATFORM))
return -ENOENT;
rc = security_kernel_load_data(LOADING_FIRMWARE, true);
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index d08efc77cf16..f86de5d7e0d7 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -68,6 +68,7 @@ struct fw_priv {
void *data;
size_t size;
size_t allocated_size;
+ u32 opt_flags;
#ifdef CONFIG_FW_LOADER_PAGED_BUF
bool is_paged_buf;
struct page **pages;
@@ -136,7 +137,7 @@ static inline void fw_state_done(struct fw_priv *fw_priv)
__fw_state_set(fw_priv, FW_STATUS_DONE);
}
-int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags);
+int assign_fw(struct firmware *fw, struct device *device);
#ifdef CONFIG_FW_LOADER_PAGED_BUF
void fw_free_paged_buf(struct fw_priv *fw_priv);
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 79f86466d472..78c8e44c08cb 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -168,7 +168,9 @@ static int fw_cache_piggyback_on_request(const char *name);
static struct fw_priv *__allocate_fw_priv(const char *fw_name,
struct firmware_cache *fwc,
- void *dbuf, size_t size)
+ void *dbuf,
+ size_t size,
+ u32 opt_flags)
{
struct fw_priv *fw_priv;
@@ -186,6 +188,7 @@ static struct fw_priv *__allocate_fw_priv(const char *fw_name,
fw_priv->fwc = fwc;
fw_priv->data = dbuf;
fw_priv->allocated_size = size;
+ fw_priv->opt_flags = opt_flags;
fw_state_init(fw_priv);
#ifdef CONFIG_FW_LOADER_USER_HELPER
INIT_LIST_HEAD(&fw_priv->pending_list);
@@ -210,8 +213,10 @@ static struct fw_priv *__lookup_fw_priv(const char *fw_name)
/* Returns 1 for batching firmware requests with the same name */
static int alloc_lookup_fw_priv(const char *fw_name,
struct firmware_cache *fwc,
- struct fw_priv **fw_priv, void *dbuf,
- size_t size, u32 opt_flags)
+ struct fw_priv **fw_priv,
+ void *dbuf,
+ size_t size,
+ u32 opt_flags)
{
struct fw_priv *tmp;
@@ -227,7 +232,7 @@ static int alloc_lookup_fw_priv(const char *fw_name,
}
}
- tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size);
+ tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, opt_flags);
if (tmp) {
INIT_LIST_HEAD(&tmp->list);
if (!(opt_flags & FW_OPT_NOCACHE))
@@ -640,7 +645,7 @@ static int fw_add_devm_name(struct device *dev, const char *name)
}
#endif
-int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags)
+int assign_fw(struct firmware *fw, struct device *device)
{
struct fw_priv *fw_priv = fw->priv;
int ret;
@@ -659,8 +664,8 @@ int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags)
* should be fixed in devres or driver core.
*/
/* don't cache firmware handled without uevent */
- if (device && (opt_flags & FW_OPT_UEVENT) &&
- !(opt_flags & FW_OPT_NOCACHE)) {
+ if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
+ !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
ret = fw_add_devm_name(device, fw_priv->fw_name);
if (ret) {
mutex_unlock(&fw_lock);
@@ -672,7 +677,7 @@ int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags)
* After caching firmware image is started, let it piggyback
* on request firmware.
*/
- if (!(opt_flags & FW_OPT_NOCACHE) &&
+ if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
fw_priv->fwc->state == FW_LOADER_START_CACHE) {
if (fw_cache_piggyback_on_request(fw_priv->fw_name))
kref_get(&fw_priv->ref);
@@ -783,7 +788,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
#endif
if (ret == -ENOENT)
- ret = firmware_fallback_platform(fw->priv, opt_flags);
+ ret = firmware_fallback_platform(fw->priv);
if (ret) {
if (!(opt_flags & FW_OPT_NO_WARN))
@@ -792,7 +797,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
name, ret);
ret = firmware_fallback_sysfs(fw, name, device, opt_flags, ret);
} else
- ret = assign_fw(fw, device, opt_flags);
+ ret = assign_fw(fw, device);
out:
if (ret < 0) {
--
2.25.1
To perform partial reads, callers of kernel_read_file*() must have a
non-NULL file_size argument and a preallocated buffer. The new "offset"
argument can then be used to seek to specific locations in the file to
fill the buffer to, at most, "buf_size" per call.
Where possible, the LSM hooks can report whether a full file has been
read or not so that the contents can be reasoned about.
Signed-off-by: Kees Cook <[email protected]>
---
drivers/base/firmware_loader/main.c | 2 +-
fs/kernel_read_file.c | 78 ++++++++++++++++++++---------
include/linux/kernel_read_file.h | 8 +--
kernel/kexec_file.c | 4 +-
kernel/module.c | 2 +-
security/integrity/digsig.c | 2 +-
security/integrity/ima/ima_fs.c | 3 +-
7 files changed, 65 insertions(+), 34 deletions(-)
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index d9a180148c4b..79f86466d472 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -499,7 +499,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
fw_priv->size = 0;
/* load firmware files from the mount namespace of init */
- rc = kernel_read_file_from_path_initns(path, &buffer, msize,
+ rc = kernel_read_file_from_path_initns(path, 0, &buffer, msize,
NULL,
READING_FIRMWARE);
if (rc < 0) {
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index d73bc3fa710a..90d255fbdd9b 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -9,6 +9,7 @@
* kernel_read_file() - read file contents into a kernel buffer
*
* @file file to read from
+ * @offset where to start reading from (see below).
* @buf pointer to a "void *" buffer for reading into (if
* *@buf is NULL, a buffer will be allocated, and
* @buf_size will be ignored)
@@ -19,19 +20,31 @@
* @id the kernel_read_file_id identifying the type of
* file contents being read (for LSMs to examine)
*
+ * @offset must be 0 unless both @buf and @file_size are non-NULL
+ * (i.e. the caller must be expecting to read partial file contents
+ * via an already-allocated @buf, in at most @buf_size chunks, and
+ * will be able to determine when the entire file was read by
+ * checking @file_size). This isn't a recommended way to read a
+ * file, though, since it is possible that the contents might
+ * change between calls to kernel_read_file().
+ *
* Returns number of bytes read (no single read will be bigger
* than INT_MAX), or negative on error.
*
*/
-int kernel_read_file(struct file *file, void **buf,
+int kernel_read_file(struct file *file, loff_t offset, void **buf,
size_t buf_size, size_t *file_size,
enum kernel_read_file_id id)
{
loff_t i_size, pos;
- ssize_t bytes = 0;
+ size_t copied;
void *allocated = NULL;
+ bool whole_file;
int ret;
+ if (offset != 0 && (!*buf || !file_size))
+ return -EINVAL;
+
if (!S_ISREG(file_inode(file)->i_mode))
return -EINVAL;
@@ -39,19 +52,27 @@ int kernel_read_file(struct file *file, void **buf,
if (ret)
return ret;
- ret = security_kernel_read_file(file, id, true);
- if (ret)
- goto out;
-
i_size = i_size_read(file_inode(file));
if (i_size <= 0) {
ret = -EINVAL;
goto out;
}
- if (i_size > INT_MAX || i_size > buf_size) {
+ /* The file is too big for sane activities. */
+ if (i_size > INT_MAX) {
+ ret = -EFBIG;
+ goto out;
+ }
+ /* The entire file cannot be read in one buffer. */
+ if (!file_size && offset == 0 && i_size > buf_size) {
ret = -EFBIG;
goto out;
}
+
+ whole_file = (offset == 0 && i_size <= buf_size);
+ ret = security_kernel_read_file(file, id, whole_file);
+ if (ret)
+ goto out;
+
if (file_size)
*file_size = i_size;
@@ -62,9 +83,14 @@ int kernel_read_file(struct file *file, void **buf,
goto out;
}
- pos = 0;
- while (pos < i_size) {
- bytes = kernel_read(file, *buf + pos, i_size - pos, &pos);
+ pos = offset;
+ copied = 0;
+ while (copied < buf_size) {
+ ssize_t bytes;
+ size_t wanted = min_t(size_t, buf_size - copied,
+ i_size - pos);
+
+ bytes = kernel_read(file, *buf + copied, wanted, &pos);
if (bytes < 0) {
ret = bytes;
goto out_free;
@@ -72,14 +98,17 @@ int kernel_read_file(struct file *file, void **buf,
if (bytes == 0)
break;
+ copied += bytes;
}
- if (pos != i_size) {
- ret = -EIO;
- goto out_free;
- }
+ if (whole_file) {
+ if (pos != i_size) {
+ ret = -EIO;
+ goto out_free;
+ }
- ret = security_kernel_post_read_file(file, *buf, i_size, id);
+ ret = security_kernel_post_read_file(file, *buf, i_size, id);
+ }
out_free:
if (ret < 0) {
@@ -91,11 +120,11 @@ int kernel_read_file(struct file *file, void **buf,
out:
allow_write_access(file);
- return ret == 0 ? pos : ret;
+ return ret == 0 ? copied : ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file);
-int kernel_read_file_from_path(const char *path, void **buf,
+int kernel_read_file_from_path(const char *path, loff_t offset, void **buf,
size_t buf_size, size_t *file_size,
enum kernel_read_file_id id)
{
@@ -109,14 +138,15 @@ int kernel_read_file_from_path(const char *path, void **buf,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, buf_size, file_size, id);
+ ret = kernel_read_file(file, offset, buf, buf_size, file_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
-int kernel_read_file_from_path_initns(const char *path, void **buf,
- size_t buf_size, size_t *file_size,
+int kernel_read_file_from_path_initns(const char *path, loff_t offset,
+ void **buf, size_t buf_size,
+ size_t *file_size,
enum kernel_read_file_id id)
{
struct file *file;
@@ -135,14 +165,14 @@ int kernel_read_file_from_path_initns(const char *path, void **buf,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, buf_size, file_size, id);
+ ret = kernel_read_file(file, offset, buf, buf_size, file_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
-int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size,
- size_t *file_size,
+int kernel_read_file_from_fd(int fd, loff_t offset, void **buf,
+ size_t buf_size, size_t *file_size,
enum kernel_read_file_id id)
{
struct fd f = fdget(fd);
@@ -151,7 +181,7 @@ int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size,
if (!f.file)
goto out;
- ret = kernel_read_file(f.file, buf, buf_size, file_size, id);
+ ret = kernel_read_file(f.file, offset, buf, buf_size, file_size, id);
out:
fdput(f);
return ret;
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
index 023293eaf948..575ffa1031d3 100644
--- a/include/linux/kernel_read_file.h
+++ b/include/linux/kernel_read_file.h
@@ -35,19 +35,19 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
return kernel_read_file_str[id];
}
-int kernel_read_file(struct file *file,
+int kernel_read_file(struct file *file, loff_t offset,
void **buf, size_t buf_size,
size_t *file_size,
enum kernel_read_file_id id);
-int kernel_read_file_from_path(const char *path,
+int kernel_read_file_from_path(const char *path, loff_t offset,
void **buf, size_t buf_size,
size_t *file_size,
enum kernel_read_file_id id);
-int kernel_read_file_from_path_initns(const char *path,
+int kernel_read_file_from_path_initns(const char *path, loff_t offset,
void **buf, size_t buf_size,
size_t *file_size,
enum kernel_read_file_id id);
-int kernel_read_file_from_fd(int fd,
+int kernel_read_file_from_fd(int fd, loff_t offset,
void **buf, size_t buf_size,
size_t *file_size,
enum kernel_read_file_id id);
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index ee51c1028658..84f7316792a7 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -221,7 +221,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
int ret;
void *ldata;
- ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
+ ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
INT_MAX, NULL, READING_KEXEC_IMAGE);
if (ret < 0)
return ret;
@@ -241,7 +241,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
#endif
/* It is possible that there no initramfs is being loaded */
if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
- ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
+ ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
INT_MAX, NULL,
READING_KEXEC_INITRAMFS);
if (ret < 0)
diff --git a/kernel/module.c b/kernel/module.c
index adfa21dd3842..9c578e44abe7 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4054,7 +4054,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
|MODULE_INIT_IGNORE_VERMAGIC))
return -EINVAL;
- err = kernel_read_file_from_fd(fd, &hdr, INT_MAX, NULL,
+ err = kernel_read_file_from_fd(fd, 0, &hdr, INT_MAX, NULL,
READING_MODULE);
if (err < 0)
return err;
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 8a523dfd7fd7..0f518dcfde05 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -175,7 +175,7 @@ int __init integrity_load_x509(const unsigned int id, const char *path)
int rc;
key_perm_t perm;
- rc = kernel_read_file_from_path(path, &data, INT_MAX, NULL,
+ rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL,
READING_X509_CERTIFICATE);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 5fc56ccb6678..ea8ff8a07b36 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -284,7 +284,8 @@ static ssize_t ima_read_policy(char *path)
datap = path;
strsep(&datap, "\n");
- rc = kernel_read_file_from_path(path, &data, INT_MAX, NULL, READING_POLICY);
+ rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL,
+ READING_POLICY);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
return rc;
--
2.25.1
Now that there is an API for checking loaded contents for modules
loaded without a file, call into the LSM hooks.
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: KP Singh <[email protected]>
Acked-by: Jessica Yu <[email protected]>
---
kernel/module.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index f47209e0fde6..adfa21dd3842 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3014,7 +3014,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
if (info->len < sizeof(*(info->hdr)))
return -ENOEXEC;
- err = security_kernel_load_data(LOADING_MODULE, false);
+ err = security_kernel_load_data(LOADING_MODULE, true);
if (err)
return err;
@@ -3024,11 +3024,17 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
return -ENOMEM;
if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
- vfree(info->hdr);
- return -EFAULT;
+ err = -EFAULT;
+ goto out;
}
- return 0;
+ err = security_kernel_post_load_data((char *)info->hdr, info->len,
+ LOADING_MODULE, "init_module");
+out:
+ if (err)
+ vfree(info->hdr);
+
+ return err;
}
static void free_copy(struct load_info *info)
--
2.25.1
From: Scott Branden <[email protected]>
When the kernel_read_file LSM hook is called with contents=false, IMA
can appraise the file directly, without requiring a filled buffer. When
such a buffer is available, though, IMA can continue to use it instead
of forcing a double read here.
Signed-off-by: Scott Branden <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
---
security/integrity/ima/ima_main.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 939f53d02627..82c9d62bcb11 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -613,11 +613,8 @@ void ima_post_path_mknod(struct dentry *dentry)
int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
bool contents)
{
- /* Reject all partial reads during appraisal. */
- if (!contents) {
- if (ima_appraise & IMA_APPRAISE_ENFORCE)
- return -EACCES;
- }
+ enum ima_hooks func;
+ u32 secid;
/*
* Do devices using pre-allocated memory run the risk of the
@@ -626,7 +623,20 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
* buffers? It may be desirable to include the buffer address
* in this API and walk all the dma_map_single() mappings to check.
*/
- return 0;
+
+ /*
+ * There will be a call made to ima_post_read_file() with
+ * a filled buffer, so we don't need to perform an extra
+ * read early here.
+ */
+ if (contents)
+ return 0;
+
+ /* Read entire file for all partial reads. */
+ func = read_idmap[read_id] ?: FILE_CHECK;
+ security_task_getsecid(current, &secid);
+ return process_measurement(file, current_cred(), secid, NULL,
+ 0, MAY_READ, func);
}
const int read_idmap[READING_MAX_ID] = {
--
2.25.1
In preparation for refactoring kernel_read_file*(), remove the redundant
"size" argument which is not needed: it can be included in the return
code, with callers adjusted. (VFS reads already cannot be larger than
INT_MAX.)
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: James Morris <[email protected]>
Acked-by: Scott Branden <[email protected]>
---
drivers/base/firmware_loader/main.c | 10 ++++++----
fs/kernel_read_file.c | 20 +++++++++-----------
include/linux/kernel_read_file.h | 8 ++++----
kernel/kexec_file.c | 14 +++++++-------
kernel/module.c | 7 +++----
security/integrity/digsig.c | 5 +++--
security/integrity/ima/ima_fs.c | 6 ++++--
7 files changed, 36 insertions(+), 34 deletions(-)
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 8c6ea389afcf..6df1bdcfeb9d 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -467,7 +467,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
size_t in_size,
const void *in_buffer))
{
- loff_t size;
+ size_t size;
int i, len;
int rc = -ENOENT;
char *path;
@@ -499,10 +499,9 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
fw_priv->size = 0;
/* load firmware files from the mount namespace of init */
- rc = kernel_read_file_from_path_initns(path, &buffer,
- &size, msize,
+ rc = kernel_read_file_from_path_initns(path, &buffer, msize,
READING_FIRMWARE);
- if (rc) {
+ if (rc < 0) {
if (rc != -ENOENT)
dev_warn(device, "loading %s failed with error %d\n",
path, rc);
@@ -511,6 +510,9 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
path);
continue;
}
+ size = rc;
+ rc = 0;
+
dev_dbg(device, "Loading firmware from %s\n", path);
if (decompress) {
dev_dbg(device, "f/w decompressing %s\n",
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index 54d972d4befc..dc28a8def597 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -5,7 +5,7 @@
#include <linux/security.h>
#include <linux/vmalloc.h>
-int kernel_read_file(struct file *file, void **buf, loff_t *size,
+int kernel_read_file(struct file *file, void **buf,
loff_t max_size, enum kernel_read_file_id id)
{
loff_t i_size, pos;
@@ -29,7 +29,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
ret = -EINVAL;
goto out;
}
- if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) {
+ if (i_size > INT_MAX || (max_size > 0 && i_size > max_size)) {
ret = -EFBIG;
goto out;
}
@@ -59,8 +59,6 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
}
ret = security_kernel_post_read_file(file, *buf, i_size, id);
- if (!ret)
- *size = pos;
out_free:
if (ret < 0) {
@@ -72,11 +70,11 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
out:
allow_write_access(file);
- return ret;
+ return ret == 0 ? pos : ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file);
-int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
+int kernel_read_file_from_path(const char *path, void **buf,
loff_t max_size, enum kernel_read_file_id id)
{
struct file *file;
@@ -89,14 +87,14 @@ int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, size, max_size, id);
+ ret = kernel_read_file(file, buf, max_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
int kernel_read_file_from_path_initns(const char *path, void **buf,
- loff_t *size, loff_t max_size,
+ loff_t max_size,
enum kernel_read_file_id id)
{
struct file *file;
@@ -115,13 +113,13 @@ int kernel_read_file_from_path_initns(const char *path, void **buf,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, size, max_size, id);
+ ret = kernel_read_file(file, buf, max_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
-int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
+int kernel_read_file_from_fd(int fd, void **buf, loff_t max_size,
enum kernel_read_file_id id)
{
struct fd f = fdget(fd);
@@ -130,7 +128,7 @@ int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
if (!f.file)
goto out;
- ret = kernel_read_file(f.file, buf, size, max_size, id);
+ ret = kernel_read_file(f.file, buf, max_size, id);
out:
fdput(f);
return ret;
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
index 78cf3d7dc835..0ca0bdbed1bd 100644
--- a/include/linux/kernel_read_file.h
+++ b/include/linux/kernel_read_file.h
@@ -36,16 +36,16 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
}
int kernel_read_file(struct file *file,
- void **buf, loff_t *size, loff_t max_size,
+ void **buf, loff_t max_size,
enum kernel_read_file_id id);
int kernel_read_file_from_path(const char *path,
- void **buf, loff_t *size, loff_t max_size,
+ void **buf, loff_t max_size,
enum kernel_read_file_id id);
int kernel_read_file_from_path_initns(const char *path,
- void **buf, loff_t *size, loff_t max_size,
+ void **buf, loff_t max_size,
enum kernel_read_file_id id);
int kernel_read_file_from_fd(int fd,
- void **buf, loff_t *size, loff_t max_size,
+ void **buf, loff_t max_size,
enum kernel_read_file_id id);
#endif /* _LINUX_KERNEL_READ_FILE_H */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 1cc82557f4c1..b20cfde8a01d 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -220,13 +220,12 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
{
int ret;
void *ldata;
- loff_t size;
ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
- &size, INT_MAX, READING_KEXEC_IMAGE);
- if (ret)
+ INT_MAX, READING_KEXEC_IMAGE);
+ if (ret < 0)
return ret;
- image->kernel_buf_len = size;
+ image->kernel_buf_len = ret;
/* Call arch image probe handlers */
ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
@@ -243,11 +242,12 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
/* It is possible that there no initramfs is being loaded */
if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
- &size, INT_MAX,
+ INT_MAX,
READING_KEXEC_INITRAMFS);
- if (ret)
+ if (ret < 0)
goto out;
- image->initrd_buf_len = size;
+ image->initrd_buf_len = ret;
+ ret = 0;
}
if (cmdline_len) {
diff --git a/kernel/module.c b/kernel/module.c
index 4218abd272ee..9faa6322f17b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4035,7 +4035,6 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
{
struct load_info info = { };
- loff_t size;
void *hdr = NULL;
int err;
@@ -4049,12 +4048,12 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
|MODULE_INIT_IGNORE_VERMAGIC))
return -EINVAL;
- err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
+ err = kernel_read_file_from_fd(fd, &hdr, INT_MAX,
READING_MODULE);
- if (err)
+ if (err < 0)
return err;
info.hdr = hdr;
- info.len = size;
+ info.len = err;
return load_module(&info, uargs, flags);
}
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index f8869be45d8f..97661ffabc4e 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -171,16 +171,17 @@ int __init integrity_add_key(const unsigned int id, const void *data,
int __init integrity_load_x509(const unsigned int id, const char *path)
{
void *data = NULL;
- loff_t size;
+ size_t size;
int rc;
key_perm_t perm;
- rc = kernel_read_file_from_path(path, &data, &size, 0,
+ rc = kernel_read_file_from_path(path, &data, 0,
READING_X509_CERTIFICATE);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
return rc;
}
+ size = rc;
perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ;
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index e13ffece3726..602f52717757 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -275,7 +275,7 @@ static ssize_t ima_read_policy(char *path)
{
void *data = NULL;
char *datap;
- loff_t size;
+ size_t size;
int rc, pathlen = strlen(path);
char *p;
@@ -284,11 +284,13 @@ static ssize_t ima_read_policy(char *path)
datap = path;
strsep(&datap, "\n");
- rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY);
+ rc = kernel_read_file_from_path(path, &data, 0, READING_POLICY);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
return rc;
}
+ size = rc;
+ rc = 0;
datap = data;
while (size > 0 && (p = strsep(&datap, "\n"))) {
--
2.25.1
There are a few places in the kernel where LSMs would like to have
visibility into the contents of a kernel buffer that has been loaded or
read. While security_kernel_post_read_file() (which includes the
buffer) exists as a pairing for security_kernel_read_file(), no such
hook exists to pair with security_kernel_load_data().
Earlier proposals for just using security_kernel_post_read_file() with a
NULL file argument were rejected (i.e. "file" should always be valid for
the security_..._file hooks, but it appears at least one case was
left in the kernel during earlier refactoring. (This will be fixed in
a subsequent patch.)
Since not all cases of security_kernel_load_data() can have a single
contiguous buffer made available to the LSM hook (e.g. kexec image
segments are separately loaded), there needs to be a way for the LSM to
reason about its expectations of the hook coverage. In order to handle
this, add a "contents" argument to the "kernel_load_data" hook that
indicates if the newly added "kernel_post_load_data" hook will be called
with the full contents once loaded. That way, LSMs requiring full contents
can choose to unilaterally reject "kernel_load_data" with contents=false
(which is effectively the existing hook coverage), but when contents=true
they can allow it and later evaluate the "kernel_post_load_data" hook
once the buffer is loaded.
With this change, LSMs can gain coverage over non-file-backed data loads
(e.g. init_module(2) and firmware userspace helper), which will happen
in subsequent patches.
Additionally prepare IMA to start processing these cases.
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: KP Singh <[email protected]>
---
drivers/base/firmware_loader/fallback.c | 2 +-
.../base/firmware_loader/fallback_platform.c | 2 +-
include/linux/ima.h | 13 ++++++++--
include/linux/lsm_hook_defs.h | 4 +++-
include/linux/lsm_hooks.h | 10 ++++++++
include/linux/security.h | 14 +++++++++--
kernel/kexec.c | 2 +-
kernel/module.c | 2 +-
security/integrity/ima/ima_main.c | 24 ++++++++++++++++++-
security/loadpin/loadpin.c | 2 +-
security/security.c | 20 +++++++++++++---
security/selinux/hooks.c | 2 +-
12 files changed, 82 insertions(+), 15 deletions(-)
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 283ca2de76d4..bff4717cc6b5 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -613,7 +613,7 @@ static bool fw_run_sysfs_fallback(u32 opt_flags)
return false;
/* Also permit LSMs and IMA to fail firmware sysfs fallback */
- ret = security_kernel_load_data(LOADING_FIRMWARE);
+ ret = security_kernel_load_data(LOADING_FIRMWARE, false);
if (ret < 0)
return false;
diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c
index 6958ab1a8059..a12c79d47efc 100644
--- a/drivers/base/firmware_loader/fallback_platform.c
+++ b/drivers/base/firmware_loader/fallback_platform.c
@@ -17,7 +17,7 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
if (!(opt_flags & FW_OPT_FALLBACK_PLATFORM))
return -ENOENT;
- rc = security_kernel_load_data(LOADING_FIRMWARE);
+ rc = security_kernel_load_data(LOADING_FIRMWARE, false);
if (rc)
return rc;
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 64804f78408b..af9fb8c5f16a 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -20,7 +20,9 @@ extern void ima_post_create_tmpfile(struct inode *inode);
extern void ima_file_free(struct file *file);
extern int ima_file_mmap(struct file *file, unsigned long prot);
extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot);
-extern int ima_load_data(enum kernel_load_data_id id);
+extern int ima_load_data(enum kernel_load_data_id id, bool contents);
+extern int ima_post_load_data(char *buf, loff_t size,
+ enum kernel_load_data_id id, char *description);
extern int ima_read_file(struct file *file, enum kernel_read_file_id id);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
@@ -78,7 +80,14 @@ static inline int ima_file_mprotect(struct vm_area_struct *vma,
return 0;
}
-static inline int ima_load_data(enum kernel_load_data_id id)
+static inline int ima_load_data(enum kernel_load_data_id id, bool contents)
+{
+ return 0;
+}
+
+static inline int ima_post_load_data(char *buf, loff_t size,
+ enum kernel_load_data_id id,
+ char *description)
{
return 0;
}
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 2a8c74d99015..83c6f1f5cc1e 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -184,7 +184,9 @@ LSM_HOOK(void, LSM_RET_VOID, cred_getsecid, const struct cred *c, u32 *secid)
LSM_HOOK(int, 0, kernel_act_as, struct cred *new, u32 secid)
LSM_HOOK(int, 0, kernel_create_files_as, struct cred *new, struct inode *inode)
LSM_HOOK(int, 0, kernel_module_request, char *kmod_name)
-LSM_HOOK(int, 0, kernel_load_data, enum kernel_load_data_id id)
+LSM_HOOK(int, 0, kernel_load_data, enum kernel_load_data_id id, bool contents)
+LSM_HOOK(int, 0, kernel_post_load_data, char *buf, loff_t size,
+ enum kernel_read_file_id id, char *description)
LSM_HOOK(int, 0, kernel_read_file, struct file *file,
enum kernel_read_file_id id)
LSM_HOOK(int, 0, kernel_post_read_file, struct file *file, char *buf,
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 9e2e3e63719d..6bb4f1a0158c 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -635,7 +635,17 @@
* @kernel_load_data:
* Load data provided by userspace.
* @id kernel load data identifier
+ * @contents if a subsequent @kernel_post_load_data will be called.
* Return 0 if permission is granted.
+ * @kernel_post_load_data:
+ * Load data provided by a non-file source (usually userspace buffer).
+ * @buf pointer to buffer containing the data contents.
+ * @size length of the data contents.
+ * @id kernel load data identifier
+ * @description a text description of what was loaded, @id-specific
+ * Return 0 if permission is granted.
+ * This must be paired with a prior @kernel_load_data call that had
+ * @contents set to true.
* @kernel_read_file:
* Read a file specified by userspace.
* @file contains the file structure pointing to the file being read
diff --git a/include/linux/security.h b/include/linux/security.h
index 42df0d9b4c37..51c8e4e6b7cc 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -387,7 +387,10 @@ void security_cred_getsecid(const struct cred *c, u32 *secid);
int security_kernel_act_as(struct cred *new, u32 secid);
int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_module_request(char *kmod_name);
-int security_kernel_load_data(enum kernel_load_data_id id);
+int security_kernel_load_data(enum kernel_load_data_id id, bool contents);
+int security_kernel_post_load_data(char *buf, loff_t size,
+ enum kernel_load_data_id id,
+ char *description);
int security_kernel_read_file(struct file *file, enum kernel_read_file_id id);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
@@ -1014,7 +1017,14 @@ static inline int security_kernel_module_request(char *kmod_name)
return 0;
}
-static inline int security_kernel_load_data(enum kernel_load_data_id id)
+static inline int security_kernel_load_data(enum kernel_load_data_id id, bool contents)
+{
+ return 0;
+}
+
+static inline int security_kernel_post_load_data(char *buf, loff_t size,
+ enum kernel_load_data_id id,
+ char *description)
{
return 0;
}
diff --git a/kernel/kexec.c b/kernel/kexec.c
index f977786fe498..c82c6c06f051 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -205,7 +205,7 @@ static inline int kexec_load_check(unsigned long nr_segments,
return -EPERM;
/* Permit LSMs and IMA to fail the kexec */
- result = security_kernel_load_data(LOADING_KEXEC_IMAGE);
+ result = security_kernel_load_data(LOADING_KEXEC_IMAGE, false);
if (result < 0)
return result;
diff --git a/kernel/module.c b/kernel/module.c
index 0f11eaed047e..f47209e0fde6 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3014,7 +3014,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
if (info->len < sizeof(*(info->hdr)))
return -ENOEXEC;
- err = security_kernel_load_data(LOADING_MODULE);
+ err = security_kernel_load_data(LOADING_MODULE, false);
if (err)
return err;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 5f89970c5ab7..9dd9c5f4d736 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -676,6 +676,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
/**
* ima_load_data - appraise decision based on policy
* @id: kernel load data caller identifier
+ * @contents: whether the full contents will be available in a later
+ * call to ima_post_load_data().
*
* Callers of this LSM hook can not measure, appraise, or audit the
* data provided by userspace. Enforce policy rules requring a file
@@ -683,7 +685,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
*
* For permission return 0, otherwise return -EACCES.
*/
-int ima_load_data(enum kernel_load_data_id id)
+int ima_load_data(enum kernel_load_data_id id, bool contents)
{
bool ima_enforce, sig_enforce;
@@ -723,6 +725,26 @@ int ima_load_data(enum kernel_load_data_id id)
return 0;
}
+/**
+ * ima_post_load_data - appraise decision based on policy
+ * @buf: pointer to in memory file contents
+ * @size: size of in memory file contents
+ * @id: kernel load data caller identifier
+ * @description: @id-specific description of contents
+ *
+ * Measure/appraise/audit in memory buffer based on policy. Policy rules
+ * are written in terms of a policy identifier.
+ *
+ * On success return 0. On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_post_load_data(char *buf, loff_t size,
+ enum kernel_load_data_id load_id,
+ char *description)
+{
+ return 0;
+}
+
/*
* process_buffer_measurement - Measure the buffer to ima log.
* @inode: inode associated with the object being measured (NULL for KEY_CHECK)
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index 163c48216d13..28782412febb 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -177,7 +177,7 @@ static int loadpin_read_file(struct file *file, enum kernel_read_file_id id)
return 0;
}
-static int loadpin_load_data(enum kernel_load_data_id id)
+static int loadpin_load_data(enum kernel_load_data_id id, bool contents)
{
return loadpin_read_file(NULL, (enum kernel_read_file_id) id);
}
diff --git a/security/security.c b/security/security.c
index 19d3150f68f4..531b855826fc 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1695,17 +1695,31 @@ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
}
EXPORT_SYMBOL_GPL(security_kernel_post_read_file);
-int security_kernel_load_data(enum kernel_load_data_id id)
+int security_kernel_load_data(enum kernel_load_data_id id, bool contents)
{
int ret;
- ret = call_int_hook(kernel_load_data, 0, id);
+ ret = call_int_hook(kernel_load_data, 0, id, contents);
if (ret)
return ret;
- return ima_load_data(id);
+ return ima_load_data(id, contents);
}
EXPORT_SYMBOL_GPL(security_kernel_load_data);
+int security_kernel_post_load_data(char *buf, loff_t size,
+ enum kernel_load_data_id id,
+ char *description)
+{
+ int ret;
+
+ ret = call_int_hook(kernel_post_load_data, 0, buf, size, id,
+ description);
+ if (ret)
+ return ret;
+ return ima_post_load_data(buf, size, id, description);
+}
+EXPORT_SYMBOL_GPL(security_kernel_post_load_data);
+
int security_task_fix_setuid(struct cred *new, const struct cred *old,
int flags)
{
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 96f5f8b3b9f0..558beee97d8d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4018,7 +4018,7 @@ static int selinux_kernel_read_file(struct file *file,
return rc;
}
-static int selinux_kernel_load_data(enum kernel_load_data_id id)
+static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
{
int rc = 0;
--
2.25.1
In preparation for further refactoring of kernel_read_file*(), rename
the "max_size" argument to the more accurate "buf_size", and correct
its type to size_t. Add kerndoc to explain the specifics of how the
arguments will be used. Note that with buf_size now size_t, it can no
longer be negative (and was never called with a negative value). Adjust
callers to use it as a "maximum size" when *buf is NULL.
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: James Morris <[email protected]>
Acked-by: Scott Branden <[email protected]>
---
fs/kernel_read_file.c | 34 +++++++++++++++++++++++---------
include/linux/kernel_read_file.h | 8 ++++----
security/integrity/digsig.c | 2 +-
security/integrity/ima/ima_fs.c | 2 +-
4 files changed, 31 insertions(+), 15 deletions(-)
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index dc28a8def597..e21a76001fff 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -5,15 +5,31 @@
#include <linux/security.h>
#include <linux/vmalloc.h>
+/**
+ * kernel_read_file() - read file contents into a kernel buffer
+ *
+ * @file file to read from
+ * @buf pointer to a "void *" buffer for reading into (if
+ * *@buf is NULL, a buffer will be allocated, and
+ * @buf_size will be ignored)
+ * @buf_size size of buf, if already allocated. If @buf not
+ * allocated, this is the largest size to allocate.
+ * @id the kernel_read_file_id identifying the type of
+ * file contents being read (for LSMs to examine)
+ *
+ * Returns number of bytes read (no single read will be bigger
+ * than INT_MAX), or negative on error.
+ *
+ */
int kernel_read_file(struct file *file, void **buf,
- loff_t max_size, enum kernel_read_file_id id)
+ size_t buf_size, enum kernel_read_file_id id)
{
loff_t i_size, pos;
ssize_t bytes = 0;
void *allocated = NULL;
int ret;
- if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0)
+ if (!S_ISREG(file_inode(file)->i_mode))
return -EINVAL;
ret = deny_write_access(file);
@@ -29,7 +45,7 @@ int kernel_read_file(struct file *file, void **buf,
ret = -EINVAL;
goto out;
}
- if (i_size > INT_MAX || (max_size > 0 && i_size > max_size)) {
+ if (i_size > INT_MAX || i_size > buf_size) {
ret = -EFBIG;
goto out;
}
@@ -75,7 +91,7 @@ int kernel_read_file(struct file *file, void **buf,
EXPORT_SYMBOL_GPL(kernel_read_file);
int kernel_read_file_from_path(const char *path, void **buf,
- loff_t max_size, enum kernel_read_file_id id)
+ size_t buf_size, enum kernel_read_file_id id)
{
struct file *file;
int ret;
@@ -87,14 +103,14 @@ int kernel_read_file_from_path(const char *path, void **buf,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, max_size, id);
+ ret = kernel_read_file(file, buf, buf_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
int kernel_read_file_from_path_initns(const char *path, void **buf,
- loff_t max_size,
+ size_t buf_size,
enum kernel_read_file_id id)
{
struct file *file;
@@ -113,13 +129,13 @@ int kernel_read_file_from_path_initns(const char *path, void **buf,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, max_size, id);
+ ret = kernel_read_file(file, buf, buf_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
-int kernel_read_file_from_fd(int fd, void **buf, loff_t max_size,
+int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size,
enum kernel_read_file_id id)
{
struct fd f = fdget(fd);
@@ -128,7 +144,7 @@ int kernel_read_file_from_fd(int fd, void **buf, loff_t max_size,
if (!f.file)
goto out;
- ret = kernel_read_file(f.file, buf, max_size, id);
+ ret = kernel_read_file(f.file, buf, buf_size, id);
out:
fdput(f);
return ret;
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
index 0ca0bdbed1bd..910039e7593e 100644
--- a/include/linux/kernel_read_file.h
+++ b/include/linux/kernel_read_file.h
@@ -36,16 +36,16 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
}
int kernel_read_file(struct file *file,
- void **buf, loff_t max_size,
+ void **buf, size_t buf_size,
enum kernel_read_file_id id);
int kernel_read_file_from_path(const char *path,
- void **buf, loff_t max_size,
+ void **buf, size_t buf_size,
enum kernel_read_file_id id);
int kernel_read_file_from_path_initns(const char *path,
- void **buf, loff_t max_size,
+ void **buf, size_t buf_size,
enum kernel_read_file_id id);
int kernel_read_file_from_fd(int fd,
- void **buf, loff_t max_size,
+ void **buf, size_t buf_size,
enum kernel_read_file_id id);
#endif /* _LINUX_KERNEL_READ_FILE_H */
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 97661ffabc4e..04f779c4f5ed 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -175,7 +175,7 @@ int __init integrity_load_x509(const unsigned int id, const char *path)
int rc;
key_perm_t perm;
- rc = kernel_read_file_from_path(path, &data, 0,
+ rc = kernel_read_file_from_path(path, &data, INT_MAX,
READING_X509_CERTIFICATE);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 602f52717757..692b83e82edf 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -284,7 +284,7 @@ static ssize_t ima_read_policy(char *path)
datap = path;
strsep(&datap, "\n");
- rc = kernel_read_file_from_path(path, &data, 0, READING_POLICY);
+ rc = kernel_read_file_from_path(path, &data, INT_MAX, READING_POLICY);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
return rc;
--
2.25.1
In preparation for adding partial read support, add an optional output
argument to kernel_read_file*() that reports the file size so callers
can reason more easily about their reading progress.
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: James Morris <[email protected]>
Acked-by: Scott Branden <[email protected]>
---
drivers/base/firmware_loader/main.c | 1 +
fs/kernel_read_file.c | 19 +++++++++++++------
include/linux/kernel_read_file.h | 4 ++++
kernel/kexec_file.c | 4 ++--
kernel/module.c | 2 +-
security/integrity/digsig.c | 2 +-
security/integrity/ima/ima_fs.c | 2 +-
7 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 6df1bdcfeb9d..d9a180148c4b 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -500,6 +500,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
/* load firmware files from the mount namespace of init */
rc = kernel_read_file_from_path_initns(path, &buffer, msize,
+ NULL,
READING_FIRMWARE);
if (rc < 0) {
if (rc != -ENOENT)
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index e21a76001fff..2e29c38eb4df 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -14,6 +14,8 @@
* @buf_size will be ignored)
* @buf_size size of buf, if already allocated. If @buf not
* allocated, this is the largest size to allocate.
+ * @file_size if non-NULL, the full size of @file will be
+ * written here.
* @id the kernel_read_file_id identifying the type of
* file contents being read (for LSMs to examine)
*
@@ -22,7 +24,8 @@
*
*/
int kernel_read_file(struct file *file, void **buf,
- size_t buf_size, enum kernel_read_file_id id)
+ size_t buf_size, size_t *file_size,
+ enum kernel_read_file_id id)
{
loff_t i_size, pos;
ssize_t bytes = 0;
@@ -49,6 +52,8 @@ int kernel_read_file(struct file *file, void **buf,
ret = -EFBIG;
goto out;
}
+ if (file_size)
+ *file_size = i_size;
if (!*buf)
*buf = allocated = vmalloc(i_size);
@@ -91,7 +96,8 @@ int kernel_read_file(struct file *file, void **buf,
EXPORT_SYMBOL_GPL(kernel_read_file);
int kernel_read_file_from_path(const char *path, void **buf,
- size_t buf_size, enum kernel_read_file_id id)
+ size_t buf_size, size_t *file_size,
+ enum kernel_read_file_id id)
{
struct file *file;
int ret;
@@ -103,14 +109,14 @@ int kernel_read_file_from_path(const char *path, void **buf,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, buf_size, id);
+ ret = kernel_read_file(file, buf, buf_size, file_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
int kernel_read_file_from_path_initns(const char *path, void **buf,
- size_t buf_size,
+ size_t buf_size, size_t *file_size,
enum kernel_read_file_id id)
{
struct file *file;
@@ -129,13 +135,14 @@ int kernel_read_file_from_path_initns(const char *path, void **buf,
if (IS_ERR(file))
return PTR_ERR(file);
- ret = kernel_read_file(file, buf, buf_size, id);
+ ret = kernel_read_file(file, buf, buf_size, file_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size,
+ size_t *file_size,
enum kernel_read_file_id id)
{
struct fd f = fdget(fd);
@@ -144,7 +151,7 @@ int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size,
if (!f.file)
goto out;
- ret = kernel_read_file(f.file, buf, buf_size, id);
+ ret = kernel_read_file(f.file, buf, buf_size, file_size, id);
out:
fdput(f);
return ret;
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
index 910039e7593e..023293eaf948 100644
--- a/include/linux/kernel_read_file.h
+++ b/include/linux/kernel_read_file.h
@@ -37,15 +37,19 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
int kernel_read_file(struct file *file,
void **buf, size_t buf_size,
+ size_t *file_size,
enum kernel_read_file_id id);
int kernel_read_file_from_path(const char *path,
void **buf, size_t buf_size,
+ size_t *file_size,
enum kernel_read_file_id id);
int kernel_read_file_from_path_initns(const char *path,
void **buf, size_t buf_size,
+ size_t *file_size,
enum kernel_read_file_id id);
int kernel_read_file_from_fd(int fd,
void **buf, size_t buf_size,
+ size_t *file_size,
enum kernel_read_file_id id);
#endif /* _LINUX_KERNEL_READ_FILE_H */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b20cfde8a01d..ee51c1028658 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -222,7 +222,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
void *ldata;
ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
- INT_MAX, READING_KEXEC_IMAGE);
+ INT_MAX, NULL, READING_KEXEC_IMAGE);
if (ret < 0)
return ret;
image->kernel_buf_len = ret;
@@ -242,7 +242,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
/* It is possible that there no initramfs is being loaded */
if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
- INT_MAX,
+ INT_MAX, NULL,
READING_KEXEC_INITRAMFS);
if (ret < 0)
goto out;
diff --git a/kernel/module.c b/kernel/module.c
index 9faa6322f17b..0f11eaed047e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4048,7 +4048,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
|MODULE_INIT_IGNORE_VERMAGIC))
return -EINVAL;
- err = kernel_read_file_from_fd(fd, &hdr, INT_MAX,
+ err = kernel_read_file_from_fd(fd, &hdr, INT_MAX, NULL,
READING_MODULE);
if (err < 0)
return err;
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 04f779c4f5ed..8a523dfd7fd7 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -175,7 +175,7 @@ int __init integrity_load_x509(const unsigned int id, const char *path)
int rc;
key_perm_t perm;
- rc = kernel_read_file_from_path(path, &data, INT_MAX,
+ rc = kernel_read_file_from_path(path, &data, INT_MAX, NULL,
READING_X509_CERTIFICATE);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 692b83e82edf..5fc56ccb6678 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -284,7 +284,7 @@ static ssize_t ima_read_policy(char *path)
datap = path;
strsep(&datap, "\n");
- rc = kernel_read_file_from_path(path, &data, INT_MAX, READING_POLICY);
+ rc = kernel_read_file_from_path(path, &data, INT_MAX, NULL, READING_POLICY);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
return rc;
--
2.25.1
From: Scott Branden <[email protected]>
Move kernel_read_file* out of linux/fs.h to its own linux/kernel_read_file.h
include file. That header gets pulled in just about everywhere
and doesn't really need functions not related to the general fs interface.
Suggested-by: Christoph Hellwig <[email protected]>
Signed-off-by: Scott Branden <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: James Morris <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
drivers/base/firmware_loader/main.c | 1 +
fs/exec.c | 1 +
include/linux/fs.h | 38 ---------------------
include/linux/ima.h | 1 +
include/linux/kernel_read_file.h | 51 +++++++++++++++++++++++++++++
include/linux/security.h | 1 +
kernel/kexec_file.c | 1 +
kernel/module.c | 1 +
security/integrity/digsig.c | 1 +
security/integrity/ima/ima_fs.c | 1 +
security/integrity/ima/ima_main.c | 1 +
security/integrity/ima/ima_policy.c | 1 +
security/loadpin/loadpin.c | 1 +
security/security.c | 1 +
security/selinux/hooks.c | 1 +
15 files changed, 64 insertions(+), 38 deletions(-)
create mode 100644 include/linux/kernel_read_file.h
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index b0ec2721f55d..8c6ea389afcf 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -12,6 +12,7 @@
#include <linux/capability.h>
#include <linux/device.h>
+#include <linux/kernel_read_file.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/timer.h>
diff --git a/fs/exec.c b/fs/exec.c
index 9233cd50dc4c..c454af329413 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -23,6 +23,7 @@
* formats.
*/
+#include <linux/kernel_read_file.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/fdtable.h>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3fb7af12d033..0885d53afb11 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2858,44 +2858,6 @@ static inline void i_readcount_inc(struct inode *inode)
#endif
extern int do_pipe_flags(int *, int);
-/* This is a list of *what* is being read, not *how* nor *where*. */
-#define __kernel_read_file_id(id) \
- id(UNKNOWN, unknown) \
- id(FIRMWARE, firmware) \
- id(MODULE, kernel-module) \
- id(KEXEC_IMAGE, kexec-image) \
- id(KEXEC_INITRAMFS, kexec-initramfs) \
- id(POLICY, security-policy) \
- id(X509_CERTIFICATE, x509-certificate) \
- id(MAX_ID, )
-
-#define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
-#define __fid_stringify(dummy, str) #str,
-
-enum kernel_read_file_id {
- __kernel_read_file_id(__fid_enumify)
-};
-
-static const char * const kernel_read_file_str[] = {
- __kernel_read_file_id(__fid_stringify)
-};
-
-static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
-{
- if ((unsigned)id >= READING_MAX_ID)
- return kernel_read_file_str[READING_UNKNOWN];
-
- return kernel_read_file_str[id];
-}
-
-extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
- enum kernel_read_file_id);
-extern int kernel_read_file_from_path(const char *, void **, loff_t *, loff_t,
- enum kernel_read_file_id);
-extern int kernel_read_file_from_path_initns(const char *, void **, loff_t *, loff_t,
- enum kernel_read_file_id);
-extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
- enum kernel_read_file_id);
extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos);
extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
diff --git a/include/linux/ima.h b/include/linux/ima.h
index d15100de6cdd..64804f78408b 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -7,6 +7,7 @@
#ifndef _LINUX_IMA_H
#define _LINUX_IMA_H
+#include <linux/kernel_read_file.h>
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/kexec.h>
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
new file mode 100644
index 000000000000..78cf3d7dc835
--- /dev/null
+++ b/include/linux/kernel_read_file.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KERNEL_READ_FILE_H
+#define _LINUX_KERNEL_READ_FILE_H
+
+#include <linux/file.h>
+#include <linux/types.h>
+
+/* This is a list of *what* is being read, not *how* nor *where*. */
+#define __kernel_read_file_id(id) \
+ id(UNKNOWN, unknown) \
+ id(FIRMWARE, firmware) \
+ id(MODULE, kernel-module) \
+ id(KEXEC_IMAGE, kexec-image) \
+ id(KEXEC_INITRAMFS, kexec-initramfs) \
+ id(POLICY, security-policy) \
+ id(X509_CERTIFICATE, x509-certificate) \
+ id(MAX_ID, )
+
+#define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
+#define __fid_stringify(dummy, str) #str,
+
+enum kernel_read_file_id {
+ __kernel_read_file_id(__fid_enumify)
+};
+
+static const char * const kernel_read_file_str[] = {
+ __kernel_read_file_id(__fid_stringify)
+};
+
+static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
+{
+ if ((unsigned int)id >= READING_MAX_ID)
+ return kernel_read_file_str[READING_UNKNOWN];
+
+ return kernel_read_file_str[id];
+}
+
+int kernel_read_file(struct file *file,
+ void **buf, loff_t *size, loff_t max_size,
+ enum kernel_read_file_id id);
+int kernel_read_file_from_path(const char *path,
+ void **buf, loff_t *size, loff_t max_size,
+ enum kernel_read_file_id id);
+int kernel_read_file_from_path_initns(const char *path,
+ void **buf, loff_t *size, loff_t max_size,
+ enum kernel_read_file_id id);
+int kernel_read_file_from_fd(int fd,
+ void **buf, loff_t *size, loff_t max_size,
+ enum kernel_read_file_id id);
+
+#endif /* _LINUX_KERNEL_READ_FILE_H */
diff --git a/include/linux/security.h b/include/linux/security.h
index 0a0a03b36a3b..42df0d9b4c37 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -23,6 +23,7 @@
#ifndef __LINUX_SECURITY_H
#define __LINUX_SECURITY_H
+#include <linux/kernel_read_file.h>
#include <linux/key.h>
#include <linux/capability.h>
#include <linux/fs.h>
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index ca40bef75a61..1cc82557f4c1 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -24,6 +24,7 @@
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/kernel.h>
+#include <linux/kernel_read_file.h>
#include <linux/syscalls.h>
#include <linux/vmalloc.h>
#include "kexec_internal.h"
diff --git a/kernel/module.c b/kernel/module.c
index b2808acac46b..4218abd272ee 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -18,6 +18,7 @@
#include <linux/fs.h>
#include <linux/sysfs.h>
#include <linux/kernel.h>
+#include <linux/kernel_read_file.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index ac02b7632353..f8869be45d8f 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -10,6 +10,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/cred.h>
+#include <linux/kernel_read_file.h>
#include <linux/key-type.h>
#include <linux/digsig.h>
#include <linux/vmalloc.h>
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 15a44c5022f7..e13ffece3726 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -13,6 +13,7 @@
*/
#include <linux/fcntl.h>
+#include <linux/kernel_read_file.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/seq_file.h>
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 2f187784c5bc..5f89970c5ab7 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -18,6 +18,7 @@
#include <linux/module.h>
#include <linux/file.h>
#include <linux/binfmts.h>
+#include <linux/kernel_read_file.h>
#include <linux/mount.h>
#include <linux/mman.h>
#include <linux/slab.h>
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index b4de33074b37..3b0b43e18ecf 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -9,6 +9,7 @@
#include <linux/init.h>
#include <linux/list.h>
+#include <linux/kernel_read_file.h>
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/magic.h>
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index 670a1aebb8a1..163c48216d13 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/fs.h>
+#include <linux/kernel_read_file.h>
#include <linux/lsm_hooks.h>
#include <linux/mount.h>
#include <linux/blkdev.h>
diff --git a/security/security.c b/security/security.c
index 70a7ad357bc6..19d3150f68f4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -16,6 +16,7 @@
#include <linux/export.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/kernel_read_file.h>
#include <linux/lsm_hooks.h>
#include <linux/integrity.h>
#include <linux/ima.h>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index a340986aa92e..96f5f8b3b9f0 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -24,6 +24,7 @@
#include <linux/init.h>
#include <linux/kd.h>
#include <linux/kernel.h>
+#include <linux/kernel_read_file.h>
#include <linux/tracehook.h>
#include <linux/errno.h>
#include <linux/sched/signal.h>
--
2.25.1
FIRMWARE_PREALLOC_BUFFER is a "how", not a "what", and confuses the LSMs
that are interested in filtering between types of things. The "how"
should be an internal detail made uninteresting to the LSMs.
Fixes: a098ecd2fa7d ("firmware: support loading into a pre-allocated buffer")
Fixes: fd90bc559bfb ("ima: based on policy verify firmware signatures (pre-allocated buffer)")
Fixes: 4f0496d8ffa3 ("ima: based on policy warn about loading firmware (pre-allocated buffer)")
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Acked-by: Scott Branden <[email protected]>
Cc: [email protected]
---
drivers/base/firmware_loader/main.c | 5 ++---
fs/exec.c | 7 ++++---
include/linux/fs.h | 2 +-
kernel/module.c | 2 +-
security/integrity/digsig.c | 2 +-
security/integrity/ima/ima_fs.c | 2 +-
security/integrity/ima/ima_main.c | 6 ++----
7 files changed, 12 insertions(+), 14 deletions(-)
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 63b9714a0154..b0ec2721f55d 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -470,14 +470,12 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
int i, len;
int rc = -ENOENT;
char *path;
- enum kernel_read_file_id id = READING_FIRMWARE;
size_t msize = INT_MAX;
void *buffer = NULL;
/* Already populated data member means we're loading into a buffer */
if (!decompress && fw_priv->data) {
buffer = fw_priv->data;
- id = READING_FIRMWARE_PREALLOC_BUFFER;
msize = fw_priv->allocated_size;
}
@@ -501,7 +499,8 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
/* load firmware files from the mount namespace of init */
rc = kernel_read_file_from_path_initns(path, &buffer,
- &size, msize, id);
+ &size, msize,
+ READING_FIRMWARE);
if (rc) {
if (rc != -ENOENT)
dev_warn(device, "loading %s failed with error %d\n",
diff --git a/fs/exec.c b/fs/exec.c
index a91003e28eaa..9233cd50dc4c 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -954,6 +954,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
{
loff_t i_size, pos;
ssize_t bytes = 0;
+ void *allocated = NULL;
int ret;
if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0)
@@ -977,8 +978,8 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
goto out;
}
- if (id != READING_FIRMWARE_PREALLOC_BUFFER)
- *buf = vmalloc(i_size);
+ if (!*buf)
+ *buf = allocated = vmalloc(i_size);
if (!*buf) {
ret = -ENOMEM;
goto out;
@@ -1007,7 +1008,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
out_free:
if (ret < 0) {
- if (id != READING_FIRMWARE_PREALLOC_BUFFER) {
+ if (allocated) {
vfree(*buf);
*buf = NULL;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7519ae003a08..7336e22d0c5d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2858,10 +2858,10 @@ static inline void i_readcount_inc(struct inode *inode)
#endif
extern int do_pipe_flags(int *, int);
+/* This is a list of *what* is being read, not *how*. */
#define __kernel_read_file_id(id) \
id(UNKNOWN, unknown) \
id(FIRMWARE, firmware) \
- id(FIRMWARE_PREALLOC_BUFFER, firmware) \
id(FIRMWARE_EFI_EMBEDDED, firmware) \
id(MODULE, kernel-module) \
id(KEXEC_IMAGE, kexec-image) \
diff --git a/kernel/module.c b/kernel/module.c
index 1c5cff34d9f2..b2808acac46b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4035,7 +4035,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
{
struct load_info info = { };
loff_t size;
- void *hdr;
+ void *hdr = NULL;
int err;
err = may_init_module();
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index e9cbadade74b..ac02b7632353 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -169,7 +169,7 @@ int __init integrity_add_key(const unsigned int id, const void *data,
int __init integrity_load_x509(const unsigned int id, const char *path)
{
- void *data;
+ void *data = NULL;
loff_t size;
int rc;
key_perm_t perm;
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index e3fcad871861..15a44c5022f7 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -272,7 +272,7 @@ static const struct file_operations ima_ascii_measurements_ops = {
static ssize_t ima_read_policy(char *path)
{
- void *data;
+ void *data = NULL;
char *datap;
loff_t size;
int rc, pathlen = strlen(path);
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 8a91711ca79b..2f187784c5bc 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -611,19 +611,17 @@ void ima_post_path_mknod(struct dentry *dentry)
int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
{
/*
- * READING_FIRMWARE_PREALLOC_BUFFER
- *
* Do devices using pre-allocated memory run the risk of the
* firmware being accessible to the device prior to the completion
* of IMA's signature verification any more than when using two
- * buffers?
+ * buffers? It may be desirable to include the buffer address
+ * in this API and walk all the dma_map_single() mappings to check.
*/
return 0;
}
const int read_idmap[READING_MAX_ID] = {
[READING_FIRMWARE] = FIRMWARE_CHECK,
- [READING_FIRMWARE_PREALLOC_BUFFER] = FIRMWARE_CHECK,
[READING_MODULE] = MODULE_CHECK,
[READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
[READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
--
2.25.1
Now that security_post_load_data() is wired up, use it instead
of the NULL file argument style of security_post_read_file(),
and update the security_kernel_load_data() call to indicate that a
security_kernel_post_load_data() call is expected.
Wire up the IMA check to match earlier logic. Perhaps a generalized
change to ima_post_load_data() might look something like this:
return process_buffer_measurement(buf, size,
kernel_load_data_id_str(load_id),
read_idmap[load_id] ?: FILE_CHECK,
0, NULL);
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
---
drivers/base/firmware_loader/fallback.c | 8 ++++----
.../base/firmware_loader/fallback_platform.c | 8 +++++++-
security/integrity/ima/ima_main.c | 20 +++++++++----------
3 files changed, 21 insertions(+), 15 deletions(-)
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index bff4717cc6b5..251d92fc8bae 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -272,9 +272,9 @@ static ssize_t firmware_loading_store(struct device *dev,
dev_err(dev, "%s: map pages failed\n",
__func__);
else
- rc = security_kernel_post_read_file(NULL,
- fw_priv->data, fw_priv->size,
- READING_FIRMWARE);
+ rc = security_kernel_post_load_data(fw_priv->data,
+ fw_priv->size,
+ LOADING_FIRMWARE, "blob");
/*
* Same logic as fw_load_abort, only the DONE bit
@@ -613,7 +613,7 @@ static bool fw_run_sysfs_fallback(u32 opt_flags)
return false;
/* Also permit LSMs and IMA to fail firmware sysfs fallback */
- ret = security_kernel_load_data(LOADING_FIRMWARE, false);
+ ret = security_kernel_load_data(LOADING_FIRMWARE, true);
if (ret < 0)
return false;
diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c
index a12c79d47efc..8bdf88043079 100644
--- a/drivers/base/firmware_loader/fallback_platform.c
+++ b/drivers/base/firmware_loader/fallback_platform.c
@@ -17,7 +17,7 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
if (!(opt_flags & FW_OPT_FALLBACK_PLATFORM))
return -ENOENT;
- rc = security_kernel_load_data(LOADING_FIRMWARE, false);
+ rc = security_kernel_load_data(LOADING_FIRMWARE, true);
if (rc)
return rc;
@@ -27,6 +27,12 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
if (fw_priv->data && size > fw_priv->allocated_size)
return -ENOMEM;
+
+ rc = security_kernel_post_load_data((u8 *)data, size, LOADING_FIRMWARE,
+ "platform");
+ if (rc)
+ return rc;
+
if (!fw_priv->data)
fw_priv->data = vmalloc(size);
if (!fw_priv->data)
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 9dd9c5f4d736..6f2b8352573a 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -648,15 +648,6 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum ima_hooks func;
u32 secid;
- if (!file && read_id == READING_FIRMWARE) {
- if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
- (ima_appraise & IMA_APPRAISE_ENFORCE)) {
- pr_err("Prevent firmware loading_store.\n");
- return -EACCES; /* INTEGRITY_UNKNOWN */
- }
- return 0;
- }
-
/* permit signed certs */
if (!file && read_id == READING_X509_CERTIFICATE)
return 0;
@@ -706,7 +697,7 @@ int ima_load_data(enum kernel_load_data_id id, bool contents)
}
break;
case LOADING_FIRMWARE:
- if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE)) {
+ if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE) && !contents) {
pr_err("Prevent firmware sysfs fallback loading.\n");
return -EACCES; /* INTEGRITY_UNKNOWN */
}
@@ -742,6 +733,15 @@ int ima_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id load_id,
char *description)
{
+ if (load_id == LOADING_FIRMWARE) {
+ if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
+ (ima_appraise & IMA_APPRAISE_ENFORCE)) {
+ pr_err("Prevent firmware loading_store.\n");
+ return -EACCES; /* INTEGRITY_UNKNOWN */
+ }
+ return 0;
+ }
+
return 0;
}
--
2.25.1
From: Scott Branden <[email protected]>
Add request_partial_firmware_into_buf() to allow for portions of a
firmware file to be read into a buffer. This is needed when large firmware
must be loaded in portions from a file on memory constrained systems.
Signed-off-by: Scott Branden <[email protected]>
Co-developed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
drivers/base/firmware_loader/firmware.h | 4 +
drivers/base/firmware_loader/main.c | 101 +++++++++++++++++++-----
include/linux/firmware.h | 12 +++
3 files changed, 99 insertions(+), 18 deletions(-)
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index f86de5d7e0d7..63bd29fdcb9c 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -32,6 +32,8 @@
* @FW_OPT_FALLBACK_PLATFORM: Enable fallback to device fw copy embedded in
* the platform's main firmware. If both this fallback and the sysfs
* fallback are enabled, then this fallback will be tried first.
+ * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
+ * entire file.
*/
enum fw_opt {
FW_OPT_UEVENT = BIT(0),
@@ -41,6 +43,7 @@ enum fw_opt {
FW_OPT_NOCACHE = BIT(4),
FW_OPT_NOFALLBACK_SYSFS = BIT(5),
FW_OPT_FALLBACK_PLATFORM = BIT(6),
+ FW_OPT_PARTIAL = BIT(7),
};
enum fw_status {
@@ -68,6 +71,7 @@ struct fw_priv {
void *data;
size_t size;
size_t allocated_size;
+ size_t offset;
u32 opt_flags;
#ifdef CONFIG_FW_LOADER_PAGED_BUF
bool is_paged_buf;
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 78c8e44c08cb..78355095e00d 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -170,10 +170,19 @@ static struct fw_priv *__allocate_fw_priv(const char *fw_name,
struct firmware_cache *fwc,
void *dbuf,
size_t size,
+ size_t offset,
u32 opt_flags)
{
struct fw_priv *fw_priv;
+ /* For a partial read, the buffer must be preallocated. */
+ if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
+ return NULL;
+
+ /* Only partial reads are allowed to use an offset. */
+ if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
+ return NULL;
+
fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
if (!fw_priv)
return NULL;
@@ -188,6 +197,7 @@ static struct fw_priv *__allocate_fw_priv(const char *fw_name,
fw_priv->fwc = fwc;
fw_priv->data = dbuf;
fw_priv->allocated_size = size;
+ fw_priv->offset = offset;
fw_priv->opt_flags = opt_flags;
fw_state_init(fw_priv);
#ifdef CONFIG_FW_LOADER_USER_HELPER
@@ -216,12 +226,17 @@ static int alloc_lookup_fw_priv(const char *fw_name,
struct fw_priv **fw_priv,
void *dbuf,
size_t size,
+ size_t offset,
u32 opt_flags)
{
struct fw_priv *tmp;
spin_lock(&fwc->lock);
- if (!(opt_flags & FW_OPT_NOCACHE)) {
+ /*
+ * Do not merge requests that are marked to be non-cached or
+ * are performing partial reads.
+ */
+ if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
tmp = __lookup_fw_priv(fw_name);
if (tmp) {
kref_get(&tmp->ref);
@@ -232,7 +247,7 @@ static int alloc_lookup_fw_priv(const char *fw_name,
}
}
- tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, opt_flags);
+ tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
if (tmp) {
INIT_LIST_HEAD(&tmp->list);
if (!(opt_flags & FW_OPT_NOCACHE))
@@ -490,6 +505,9 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
+ size_t file_size = 0;
+ size_t *file_size_ptr = NULL;
+
/* skip the unset customized path */
if (!fw_path[i][0])
continue;
@@ -503,9 +521,18 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
fw_priv->size = 0;
+ /*
+ * The total file size is only examined when doing a partial
+ * read; the "full read" case needs to fail if the whole
+ * firmware was not completely loaded.
+ */
+ if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
+ file_size_ptr = &file_size;
+
/* load firmware files from the mount namespace of init */
- rc = kernel_read_file_from_path_initns(path, 0, &buffer, msize,
- NULL,
+ rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
+ &buffer, msize,
+ file_size_ptr,
READING_FIRMWARE);
if (rc < 0) {
if (rc != -ENOENT)
@@ -696,7 +723,7 @@ int assign_fw(struct firmware *fw, struct device *device)
static int
_request_firmware_prepare(struct firmware **firmware_p, const char *name,
struct device *device, void *dbuf, size_t size,
- u32 opt_flags)
+ size_t offset, u32 opt_flags)
{
struct firmware *firmware;
struct fw_priv *fw_priv;
@@ -715,7 +742,7 @@ _request_firmware_prepare(struct firmware **firmware_p, const char *name,
}
ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
- opt_flags);
+ offset, opt_flags);
/*
* bind with 'priv' now to avoid warning in failure path
@@ -762,9 +789,10 @@ static void fw_abort_batch_reqs(struct firmware *fw)
static int
_request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device, void *buf, size_t size,
- u32 opt_flags)
+ size_t offset, u32 opt_flags)
{
struct firmware *fw = NULL;
+ bool nondirect = false;
int ret;
if (!firmware_p)
@@ -776,18 +804,22 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
}
ret = _request_firmware_prepare(&fw, name, device, buf, size,
- opt_flags);
+ offset, opt_flags);
if (ret <= 0) /* error or already assigned */
goto out;
ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
+
+ /* Only full reads can support decompression, platform, and sysfs. */
+ if (!(opt_flags & FW_OPT_PARTIAL))
+ nondirect = true;
+
#ifdef CONFIG_FW_LOADER_COMPRESS
- if (ret == -ENOENT)
+ if (ret == -ENOENT && nondirect)
ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
fw_decompress_xz);
#endif
-
- if (ret == -ENOENT)
+ if (ret == -ENOENT && nondirect)
ret = firmware_fallback_platform(fw->priv);
if (ret) {
@@ -795,7 +827,9 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
dev_warn(device,
"Direct firmware load for %s failed with error %d\n",
name, ret);
- ret = firmware_fallback_sysfs(fw, name, device, opt_flags, ret);
+ if (nondirect)
+ ret = firmware_fallback_sysfs(fw, name, device,
+ opt_flags, ret);
} else
ret = assign_fw(fw, device);
@@ -838,7 +872,7 @@ request_firmware(const struct firmware **firmware_p, const char *name,
/* Need to pin this module until return */
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware_p, name, device, NULL, 0,
+ ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
FW_OPT_UEVENT);
module_put(THIS_MODULE);
return ret;
@@ -865,7 +899,7 @@ int firmware_request_nowarn(const struct firmware **firmware, const char *name,
/* Need to pin this module until return */
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware, name, device, NULL, 0,
+ ret = _request_firmware(firmware, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN);
module_put(THIS_MODULE);
return ret;
@@ -889,7 +923,7 @@ int request_firmware_direct(const struct firmware **firmware_p,
int ret;
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware_p, name, device, NULL, 0,
+ ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN |
FW_OPT_NOFALLBACK_SYSFS);
module_put(THIS_MODULE);
@@ -914,7 +948,7 @@ int firmware_request_platform(const struct firmware **firmware,
/* Need to pin this module until return */
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware, name, device, NULL, 0,
+ ret = _request_firmware(firmware, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
module_put(THIS_MODULE);
return ret;
@@ -970,13 +1004,44 @@ request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
return -EOPNOTSUPP;
__module_get(THIS_MODULE);
- ret = _request_firmware(firmware_p, name, device, buf, size,
+ ret = _request_firmware(firmware_p, name, device, buf, size, 0,
FW_OPT_UEVENT | FW_OPT_NOCACHE);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_firmware_into_buf);
+/**
+ * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
+ * @firmware_p: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded and DMA region allocated
+ * @buf: address of buffer to load firmware into
+ * @size: size of buffer
+ * @offset: offset into file to read
+ *
+ * This function works pretty much like request_firmware_into_buf except
+ * it allows a partial read of the file.
+ */
+int
+request_partial_firmware_into_buf(const struct firmware **firmware_p,
+ const char *name, struct device *device,
+ void *buf, size_t size, size_t offset)
+{
+ int ret;
+
+ if (fw_cache_is_setup(device, name))
+ return -EOPNOTSUPP;
+
+ __module_get(THIS_MODULE);
+ ret = _request_firmware(firmware_p, name, device, buf, size, offset,
+ FW_OPT_UEVENT | FW_OPT_NOCACHE |
+ FW_OPT_PARTIAL);
+ module_put(THIS_MODULE);
+ return ret;
+}
+EXPORT_SYMBOL(request_partial_firmware_into_buf);
+
/**
* release_firmware() - release the resource associated with a firmware image
* @fw: firmware resource to release
@@ -1009,7 +1074,7 @@ static void request_firmware_work_func(struct work_struct *work)
fw_work = container_of(work, struct firmware_work, work);
- _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
+ _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
fw_work->opt_flags);
fw_work->cont(fw, fw_work->context);
put_device(fw_work->device); /* taken in request_firmware_nowait() */
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index cb3e2c06ed8a..c15acadc6cf4 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -53,6 +53,9 @@ int request_firmware_direct(const struct firmware **fw, const char *name,
struct device *device);
int request_firmware_into_buf(const struct firmware **firmware_p,
const char *name, struct device *device, void *buf, size_t size);
+int request_partial_firmware_into_buf(const struct firmware **firmware_p,
+ const char *name, struct device *device,
+ void *buf, size_t size, size_t offset);
void release_firmware(const struct firmware *fw);
#else
@@ -102,6 +105,15 @@ static inline int request_firmware_into_buf(const struct firmware **firmware_p,
return -EINVAL;
}
+static inline int request_partial_firmware_into_buf
+ (const struct firmware **firmware_p,
+ const char *name,
+ struct device *device,
+ void *buf, size_t size, size_t offset)
+{
+ return -EINVAL;
+}
+
#endif
int firmware_request_cache(struct device *device, const char *name);
--
2.25.1
The "FIRMWARE_EFI_EMBEDDED" enum is a "where", not a "what". It
should not be distinguished separately from just "FIRMWARE", as this
confuses the LSMs about what is being loaded. Additionally, there was
no actual validation of the firmware contents happening.
Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firmware_request_platform()")
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Acked-by: Scott Branden <[email protected]>
Cc: [email protected]
---
drivers/base/firmware_loader/fallback_platform.c | 2 +-
include/linux/fs.h | 3 +--
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c
index 685edb7dd05a..6958ab1a8059 100644
--- a/drivers/base/firmware_loader/fallback_platform.c
+++ b/drivers/base/firmware_loader/fallback_platform.c
@@ -17,7 +17,7 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
if (!(opt_flags & FW_OPT_FALLBACK_PLATFORM))
return -ENOENT;
- rc = security_kernel_load_data(LOADING_FIRMWARE_EFI_EMBEDDED);
+ rc = security_kernel_load_data(LOADING_FIRMWARE);
if (rc)
return rc;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7336e22d0c5d..3fb7af12d033 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2858,11 +2858,10 @@ static inline void i_readcount_inc(struct inode *inode)
#endif
extern int do_pipe_flags(int *, int);
-/* This is a list of *what* is being read, not *how*. */
+/* This is a list of *what* is being read, not *how* nor *where*. */
#define __kernel_read_file_id(id) \
id(UNKNOWN, unknown) \
id(FIRMWARE, firmware) \
- id(FIRMWARE_EFI_EMBEDDED, firmware) \
id(MODULE, kernel-module) \
id(KEXEC_IMAGE, kexec-image) \
id(KEXEC_INITRAMFS, kexec-initramfs) \
--
2.25.1
From: Scott Branden <[email protected]>
Add additional hooks to test_firmware to pass in support
for partial file read using request_firmware_into_buf():
buf_size: size of buffer to request firmware into
partial: indicates that a partial file request is being made
file_offset: to indicate offset into file to request
Also update firmware selftests to use the new partial read test API.
Signed-off-by: Scott Branden <[email protected]>
Co-developed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
lib/test_firmware.c | 154 ++++++++++++++++--
.../selftests/firmware/fw_filesystem.sh | 91 +++++++++++
2 files changed, 233 insertions(+), 12 deletions(-)
diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 06c955057756..2baa275a6ddf 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -52,6 +52,9 @@ struct test_batched_req {
* @name: the name of the firmware file to look for
* @into_buf: when the into_buf is used if this is true
* request_firmware_into_buf() will be used instead.
+ * @buf_size: size of buf to allocate when into_buf is true
+ * @file_offset: file offset to request when calling request_firmware_into_buf
+ * @partial: partial read opt when calling request_firmware_into_buf
* @sync_direct: when the sync trigger is used if this is true
* request_firmware_direct() will be used instead.
* @send_uevent: whether or not to send a uevent for async requests
@@ -91,6 +94,9 @@ struct test_batched_req {
struct test_config {
char *name;
bool into_buf;
+ size_t buf_size;
+ size_t file_offset;
+ bool partial;
bool sync_direct;
bool send_uevent;
u8 num_requests;
@@ -185,6 +191,9 @@ static int __test_firmware_config_init(void)
test_fw_config->num_requests = TEST_FIRMWARE_NUM_REQS;
test_fw_config->send_uevent = true;
test_fw_config->into_buf = false;
+ test_fw_config->buf_size = TEST_FIRMWARE_BUF_SIZE;
+ test_fw_config->file_offset = 0;
+ test_fw_config->partial = false;
test_fw_config->sync_direct = false;
test_fw_config->req_firmware = request_firmware;
test_fw_config->test_result = 0;
@@ -238,28 +247,35 @@ static ssize_t config_show(struct device *dev,
dev_name(dev));
if (test_fw_config->name)
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"name:\t%s\n",
test_fw_config->name);
else
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"name:\tEMTPY\n");
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"num_requests:\t%u\n", test_fw_config->num_requests);
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"send_uevent:\t\t%s\n",
test_fw_config->send_uevent ?
"FW_ACTION_HOTPLUG" :
"FW_ACTION_NOHOTPLUG");
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"into_buf:\t\t%s\n",
test_fw_config->into_buf ? "true" : "false");
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "buf_size:\t%zu\n", test_fw_config->buf_size);
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "file_offset:\t%zu\n", test_fw_config->file_offset);
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "partial:\t\t%s\n",
+ test_fw_config->partial ? "true" : "false");
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"sync_direct:\t\t%s\n",
test_fw_config->sync_direct ? "true" : "false");
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"read_fw_idx:\t%u\n", test_fw_config->read_fw_idx);
mutex_unlock(&test_fw_mutex);
@@ -317,6 +333,30 @@ static ssize_t test_dev_config_show_bool(char *buf, bool val)
return snprintf(buf, PAGE_SIZE, "%d\n", val);
}
+static int test_dev_config_update_size_t(const char *buf,
+ size_t size,
+ size_t *cfg)
+{
+ int ret;
+ long new;
+
+ ret = kstrtol(buf, 10, &new);
+ if (ret)
+ return ret;
+
+ mutex_lock(&test_fw_mutex);
+ *(size_t *)cfg = new;
+ mutex_unlock(&test_fw_mutex);
+
+ /* Always return full write size even if we didn't consume all */
+ return size;
+}
+
+static ssize_t test_dev_config_show_size_t(char *buf, size_t val)
+{
+ return snprintf(buf, PAGE_SIZE, "%zu\n", val);
+}
+
static ssize_t test_dev_config_show_int(char *buf, int val)
{
return snprintf(buf, PAGE_SIZE, "%d\n", val);
@@ -402,6 +442,83 @@ static ssize_t config_into_buf_show(struct device *dev,
}
static DEVICE_ATTR_RW(config_into_buf);
+static ssize_t config_buf_size_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc;
+
+ mutex_lock(&test_fw_mutex);
+ if (test_fw_config->reqs) {
+ pr_err("Must call release_all_firmware prior to changing config\n");
+ rc = -EINVAL;
+ mutex_unlock(&test_fw_mutex);
+ goto out;
+ }
+ mutex_unlock(&test_fw_mutex);
+
+ rc = test_dev_config_update_size_t(buf, count,
+ &test_fw_config->buf_size);
+
+out:
+ return rc;
+}
+
+static ssize_t config_buf_size_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return test_dev_config_show_size_t(buf, test_fw_config->buf_size);
+}
+static DEVICE_ATTR_RW(config_buf_size);
+
+static ssize_t config_file_offset_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc;
+
+ mutex_lock(&test_fw_mutex);
+ if (test_fw_config->reqs) {
+ pr_err("Must call release_all_firmware prior to changing config\n");
+ rc = -EINVAL;
+ mutex_unlock(&test_fw_mutex);
+ goto out;
+ }
+ mutex_unlock(&test_fw_mutex);
+
+ rc = test_dev_config_update_size_t(buf, count,
+ &test_fw_config->file_offset);
+
+out:
+ return rc;
+}
+
+static ssize_t config_file_offset_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return test_dev_config_show_size_t(buf, test_fw_config->file_offset);
+}
+static DEVICE_ATTR_RW(config_file_offset);
+
+static ssize_t config_partial_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return test_dev_config_update_bool(buf,
+ count,
+ &test_fw_config->partial);
+}
+
+static ssize_t config_partial_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return test_dev_config_show_bool(buf, test_fw_config->partial);
+}
+static DEVICE_ATTR_RW(config_partial);
+
static ssize_t config_sync_direct_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
@@ -659,11 +776,21 @@ static int test_fw_run_batch_request(void *data)
if (!test_buf)
return -ENOSPC;
- req->rc = request_firmware_into_buf(&req->fw,
- req->name,
- req->dev,
- test_buf,
- TEST_FIRMWARE_BUF_SIZE);
+ if (test_fw_config->partial)
+ req->rc = request_partial_firmware_into_buf
+ (&req->fw,
+ req->name,
+ req->dev,
+ test_buf,
+ test_fw_config->buf_size,
+ test_fw_config->file_offset);
+ else
+ req->rc = request_firmware_into_buf
+ (&req->fw,
+ req->name,
+ req->dev,
+ test_buf,
+ test_fw_config->buf_size);
if (!req->fw)
kfree(test_buf);
} else {
@@ -936,6 +1063,9 @@ static struct attribute *test_dev_attrs[] = {
TEST_FW_DEV_ATTR(config_name),
TEST_FW_DEV_ATTR(config_num_requests),
TEST_FW_DEV_ATTR(config_into_buf),
+ TEST_FW_DEV_ATTR(config_buf_size),
+ TEST_FW_DEV_ATTR(config_file_offset),
+ TEST_FW_DEV_ATTR(config_partial),
TEST_FW_DEV_ATTR(config_sync_direct),
TEST_FW_DEV_ATTR(config_send_uevent),
TEST_FW_DEV_ATTR(config_read_fw_idx),
diff --git a/tools/testing/selftests/firmware/fw_filesystem.sh b/tools/testing/selftests/firmware/fw_filesystem.sh
index fcc281373b4d..c2a2a100114b 100755
--- a/tools/testing/selftests/firmware/fw_filesystem.sh
+++ b/tools/testing/selftests/firmware/fw_filesystem.sh
@@ -149,6 +149,26 @@ config_unset_into_buf()
echo 0 > $DIR/config_into_buf
}
+config_set_buf_size()
+{
+ echo $1 > $DIR/config_buf_size
+}
+
+config_set_file_offset()
+{
+ echo $1 > $DIR/config_file_offset
+}
+
+config_set_partial()
+{
+ echo 1 > $DIR/config_partial
+}
+
+config_unset_partial()
+{
+ echo 0 > $DIR/config_partial
+}
+
config_set_sync_direct()
{
echo 1 > $DIR/config_sync_direct
@@ -207,6 +227,35 @@ read_firmwares()
done
}
+read_partial_firmwares()
+{
+ if [ "$(cat $DIR/config_into_buf)" == "1" ]; then
+ fwfile="${FW_INTO_BUF}"
+ else
+ fwfile="${FW}"
+ fi
+
+ if [ "$1" = "xzonly" ]; then
+ fwfile="${fwfile}-orig"
+ fi
+
+ # Strip fwfile down to match partial offset and length
+ partial_data="$(cat $fwfile)"
+ partial_data="${partial_data:$2:$3}"
+
+ for i in $(seq 0 3); do
+ config_set_read_fw_idx $i
+
+ read_firmware="$(cat $DIR/read_firmware)"
+
+ # Verify the contents are what we expect.
+ if [ $read_firmware != $partial_data ]; then
+ echo "request #$i: partial firmware was not loaded" >&2
+ exit 1
+ fi
+ done
+}
+
read_firmwares_expect_nofile()
{
for i in $(seq 0 3); do
@@ -242,6 +291,21 @@ test_batched_request_firmware_into_buf_nofile()
echo "OK"
}
+test_request_partial_firmware_into_buf_nofile()
+{
+ echo -n "Test request_partial_firmware_into_buf() off=$1 size=$2 nofile: "
+ config_reset
+ config_set_name nope-test-firmware.bin
+ config_set_into_buf
+ config_set_partial
+ config_set_buf_size $2
+ config_set_file_offset $1
+ config_trigger_sync
+ read_firmwares_expect_nofile
+ release_all_firmware
+ echo "OK"
+}
+
test_batched_request_firmware_direct_nofile()
{
echo -n "Batched request_firmware_direct() nofile try #$1: "
@@ -356,6 +420,21 @@ test_request_firmware_nowait_custom()
echo "OK"
}
+test_request_partial_firmware_into_buf()
+{
+ echo -n "Test request_partial_firmware_into_buf() off=$1 size=$2: "
+ config_reset
+ config_set_name $TEST_FIRMWARE_INTO_BUF_FILENAME
+ config_set_into_buf
+ config_set_partial
+ config_set_buf_size $2
+ config_set_file_offset $1
+ config_trigger_sync
+ read_partial_firmwares normal $1 $2
+ release_all_firmware
+ echo "OK"
+}
+
# Only continue if batched request triggers are present on the
# test-firmware driver
test_config_present
@@ -383,6 +462,12 @@ for i in $(seq 1 5); do
test_request_firmware_nowait_custom $i normal
done
+# Partial loads cannot use fallback, so do not repeat tests.
+test_request_partial_firmware_into_buf 0 10
+test_request_partial_firmware_into_buf 0 5
+test_request_partial_firmware_into_buf 1 6
+test_request_partial_firmware_into_buf 2 10
+
# Test for file not found, errors are expected, the failure would be
# a hung task, which would require a hard reset.
echo
@@ -407,6 +492,12 @@ for i in $(seq 1 5); do
test_request_firmware_nowait_custom_nofile $i
done
+# Partial loads cannot use fallback, so do not repeat tests.
+test_request_partial_firmware_into_buf_nofile 0 10
+test_request_partial_firmware_into_buf_nofile 0 5
+test_request_partial_firmware_into_buf_nofile 1 6
+test_request_partial_firmware_into_buf_nofile 2 10
+
test "$HAS_FW_LOADER_COMPRESS" != "yes" && exit 0
# test with both files present
--
2.25.1
On Fri, 2 Oct 2020, Kees Cook wrote:
> FIRMWARE_PREALLOC_BUFFER is a "how", not a "what", and confuses the LSMs
> that are interested in filtering between types of things. The "how"
> should be an internal detail made uninteresting to the LSMs.
>
> Fixes: a098ecd2fa7d ("firmware: support loading into a pre-allocated buffer")
> Fixes: fd90bc559bfb ("ima: based on policy verify firmware signatures (pre-allocated buffer)")
> Fixes: 4f0496d8ffa3 ("ima: based on policy warn about loading firmware (pre-allocated buffer)")
> Signed-off-by: Kees Cook <[email protected]>
> Reviewed-by: Mimi Zohar <[email protected]>
> Reviewed-by: Luis Chamberlain <[email protected]>
> Acked-by: Scott Branden <[email protected]>
> Cc: [email protected]
Reviewed-by: James Morris <[email protected]>
--
James Morris
<[email protected]>
On Fri, 2 Oct 2020, Kees Cook wrote:
> Signed-off-by: Kees Cook <[email protected]>
> Reviewed-by: Mimi Zohar <[email protected]>
Reviewed-by: James Morris <[email protected]>
--
James Morris
<[email protected]>
On Fri, 2 Oct 2020, Kees Cook wrote:
> Now that there is an API for checking loaded contents for modules
> loaded without a file, call into the LSM hooks.
>
> Signed-off-by: Kees Cook <[email protected]>
> Reviewed-by: KP Singh <[email protected]>
> Acked-by: Jessica Yu <[email protected]>
Reviewed-by: James Morris <[email protected]>
--
James Morris
<[email protected]>
On Fri, 2 Oct 2020, Kees Cook wrote:
> These routines are used in places outside of exec(2), so in preparation
> for refactoring them, move them into a separate source file,
> fs/kernel_read_file.c.
>
> Signed-off-by: Kees Cook <[email protected]>
> Reviewed-by: Mimi Zohar <[email protected]>
> Reviewed-by: Luis Chamberlain <[email protected]>
> Acked-by: Scott Branden <[email protected]>
Reviewed-by: James Morris <[email protected]>
--
James Morris
<[email protected]>