SELinux would like to implement a new labeling behavior of newly created
inodes. We currently label new inodes based on the parent and the creating
process. This new behavior would also take into account the name of the
new object when deciding the new label. This is not the (supposed) full path,
just the last component of the path.
This is very useful because creating /etc/shadow is different than creating
/etc/passwd but the kernel hooks are unable to differentiate these
operations. We currently require that userspace realize it is doing some
difficult operation like that and than userspace jumps through SELinux hoops
to get things set up correctly. This patch does not implement new
behavior, that is obviously contained in a seperate SELinux patch, but it
does pass the needed name down to the correct LSM hook. If no such name
exists it is fine to pass NULL.
Signed-off-by: Eric Paris <[email protected]>
---
fs/btrfs/inode.c | 13 +++++++------
fs/btrfs/xattr.c | 6 ++++--
fs/btrfs/xattr.h | 3 ++-
fs/ext2/ext2.h | 2 +-
fs/ext2/ialloc.c | 5 +++--
fs/ext2/namei.c | 8 ++++----
fs/ext2/xattr.h | 6 ++++--
fs/ext2/xattr_security.c | 5 +++--
fs/ext3/ialloc.c | 5 +++--
fs/ext3/namei.c | 8 ++++----
fs/ext3/xattr.h | 4 ++--
fs/ext3/xattr_security.c | 5 +++--
fs/ext4/ialloc.c | 2 +-
fs/ext4/xattr.h | 4 ++--
fs/ext4/xattr_security.c | 5 +++--
fs/gfs2/inode.c | 7 ++++---
fs/jffs2/dir.c | 9 ++++-----
fs/jffs2/nodelist.h | 2 +-
fs/jffs2/security.c | 5 +++--
fs/jffs2/write.c | 18 ++++++++++--------
fs/jffs2/xattr.h | 5 +++--
fs/jfs/jfs_xattr.h | 5 +++--
fs/jfs/namei.c | 8 ++++----
fs/jfs/xattr.c | 6 ++++--
fs/ocfs2/namei.c | 4 ++--
fs/ocfs2/refcounttree.c | 3 ++-
fs/ocfs2/xattr.c | 10 ++++++----
fs/ocfs2/xattr.h | 4 +++-
fs/reiserfs/namei.c | 9 +++++----
fs/reiserfs/xattr_security.c | 3 ++-
fs/xfs/linux-2.6/xfs_iops.c | 9 +++++----
include/linux/ext3_fs.h | 3 ++-
include/linux/reiserfs_xattr.h | 2 ++
include/linux/security.h | 9 +++++++--
mm/shmem.c | 9 +++++----
security/capability.c | 3 ++-
security/security.c | 6 ++++--
security/selinux/hooks.c | 5 +++--
security/smack/smack_lsm.c | 5 ++++-
39 files changed, 136 insertions(+), 94 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8039390..ffc6e15 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -90,13 +90,14 @@ static noinline int cow_file_range(struct inode *inode,
unsigned long *nr_written, int unlock);
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
- struct inode *inode, struct inode *dir)
+ struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
int err;
err = btrfs_init_acl(trans, inode, dir);
if (!err)
- err = btrfs_xattr_security_init(trans, inode, dir);
+ err = btrfs_xattr_security_init(trans, inode, dir, qstr);
return err;
}
@@ -4675,7 +4676,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
if (IS_ERR(inode))
goto out_unlock;
- err = btrfs_init_inode_security(trans, inode, dir);
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err) {
drop_inode = 1;
goto out_unlock;
@@ -4736,7 +4737,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
if (IS_ERR(inode))
goto out_unlock;
- err = btrfs_init_inode_security(trans, inode, dir);
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err) {
drop_inode = 1;
goto out_unlock;
@@ -4864,7 +4865,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
drop_on_err = 1;
- err = btrfs_init_inode_security(trans, inode, dir);
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_fail;
@@ -6940,7 +6941,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
if (IS_ERR(inode))
goto out_unlock;
- err = btrfs_init_inode_security(trans, inode, dir);
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err) {
drop_inode = 1;
goto out_unlock;
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 698fdd2..3338a7e 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -352,7 +352,8 @@ int btrfs_removexattr(struct dentry *dentry, const char *name)
}
int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
- struct inode *inode, struct inode *dir)
+ struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
int err;
size_t len;
@@ -360,7 +361,8 @@ int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
char *suffix;
char *name;
- err = security_inode_init_security(inode, dir, &suffix, &value, &len);
+ err = security_inode_init_security(inode, dir, qstr, &suffix, &value,
+ &len);
if (err) {
if (err == -EOPNOTSUPP)
return 0;
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
index 7a43fd6..b3cc803 100644
--- a/fs/btrfs/xattr.h
+++ b/fs/btrfs/xattr.h
@@ -37,6 +37,7 @@ extern int btrfs_setxattr(struct dentry *dentry, const char *name,
extern int btrfs_removexattr(struct dentry *dentry, const char *name);
extern int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
- struct inode *inode, struct inode *dir);
+ struct inode *inode, struct inode *dir,
+ const struct qstr *qstr);
#endif /* __XATTR__ */
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 6346a2a..1b48c33 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -110,7 +110,7 @@ extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int);
/* ialloc.c */
-extern struct inode * ext2_new_inode (struct inode *, int);
+extern struct inode * ext2_new_inode (struct inode *, int, const struct qstr *);
extern void ext2_free_inode (struct inode *);
extern unsigned long ext2_count_free_inodes (struct super_block *);
extern void ext2_check_inodes_bitmap (struct super_block *);
diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index ad70479..ee9ed31 100644
--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -429,7 +429,8 @@ found:
return group;
}
-struct inode *ext2_new_inode(struct inode *dir, int mode)
+struct inode *ext2_new_inode(struct inode *dir, int mode,
+ const struct qstr *qstr)
{
struct super_block *sb;
struct buffer_head *bitmap_bh = NULL;
@@ -585,7 +586,7 @@ got:
if (err)
goto fail_free_drop;
- err = ext2_init_security(inode,dir);
+ err = ext2_init_security(inode, dir, qstr);
if (err)
goto fail_free_drop;
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index f8aecd2..368d704 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -104,7 +104,7 @@ static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, st
dquot_initialize(dir);
- inode = ext2_new_inode(dir, mode);
+ inode = ext2_new_inode(dir, mode, &dentry->d_name);
if (IS_ERR(inode))
return PTR_ERR(inode);
@@ -133,7 +133,7 @@ static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_
dquot_initialize(dir);
- inode = ext2_new_inode (dir, mode);
+ inode = ext2_new_inode (dir, mode, &dentry->d_name);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
@@ -159,7 +159,7 @@ static int ext2_symlink (struct inode * dir, struct dentry * dentry,
dquot_initialize(dir);
- inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
+ inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out;
@@ -230,7 +230,7 @@ static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
inode_inc_link_count(dir);
- inode = ext2_new_inode (dir, S_IFDIR | mode);
+ inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_dir;
diff --git a/fs/ext2/xattr.h b/fs/ext2/xattr.h
index a1a1c21..5e41ccc 100644
--- a/fs/ext2/xattr.h
+++ b/fs/ext2/xattr.h
@@ -116,9 +116,11 @@ exit_ext2_xattr(void)
# endif /* CONFIG_EXT2_FS_XATTR */
#ifdef CONFIG_EXT2_FS_SECURITY
-extern int ext2_init_security(struct inode *inode, struct inode *dir);
+extern int ext2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr);
#else
-static inline int ext2_init_security(struct inode *inode, struct inode *dir)
+static inline int ext2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
return 0;
}
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index 3004e15..5d979b4 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -47,14 +47,15 @@ ext2_xattr_security_set(struct dentry *dentry, const char *name,
}
int
-ext2_init_security(struct inode *inode, struct inode *dir)
+ext2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
int err;
size_t len;
void *value;
char *name;
- err = security_inode_init_security(inode, dir, &name, &value, &len);
+ err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
if (err) {
if (err == -EOPNOTSUPP)
return 0;
diff --git a/fs/ext3/ialloc.c b/fs/ext3/ialloc.c
index 9724aef..bfc2dc4 100644
--- a/fs/ext3/ialloc.c
+++ b/fs/ext3/ialloc.c
@@ -404,7 +404,8 @@ static int find_group_other(struct super_block *sb, struct inode *parent)
* For other inodes, search forward from the parent directory's block
* group to find a free inode.
*/
-struct inode *ext3_new_inode(handle_t *handle, struct inode * dir, int mode)
+struct inode *ext3_new_inode(handle_t *handle, struct inode * dir,
+ const struct qstr *qstr, int mode)
{
struct super_block *sb;
struct buffer_head *bitmap_bh = NULL;
@@ -589,7 +590,7 @@ got:
if (err)
goto fail_free_drop;
- err = ext3_init_security(handle,inode, dir);
+ err = ext3_init_security(handle, inode, dir, qstr);
if (err)
goto fail_free_drop;
diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index bce9dce..a900033 100644
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -1707,7 +1707,7 @@ retry:
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
- inode = ext3_new_inode (handle, dir, mode);
+ inode = ext3_new_inode (handle, dir, &dentry->d_name, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext3_file_inode_operations;
@@ -1743,7 +1743,7 @@ retry:
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
- inode = ext3_new_inode (handle, dir, mode);
+ inode = ext3_new_inode (handle, dir, &dentry->d_name, mode);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
@@ -1781,7 +1781,7 @@ retry:
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
- inode = ext3_new_inode (handle, dir, S_IFDIR | mode);
+ inode = ext3_new_inode (handle, dir, &dentry->d_name, S_IFDIR | mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
@@ -2195,7 +2195,7 @@ retry:
if (IS_DIRSYNC(dir))
handle->h_sync = 1;
- inode = ext3_new_inode (handle, dir, S_IFLNK|S_IRWXUGO);
+ inode = ext3_new_inode (handle, dir, &dentry->d_name, S_IFLNK|S_IRWXUGO);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
diff --git a/fs/ext3/xattr.h b/fs/ext3/xattr.h
index 377fe72..2be4f69 100644
--- a/fs/ext3/xattr.h
+++ b/fs/ext3/xattr.h
@@ -128,10 +128,10 @@ exit_ext3_xattr(void)
#ifdef CONFIG_EXT3_FS_SECURITY
extern int ext3_init_security(handle_t *handle, struct inode *inode,
- struct inode *dir);
+ struct inode *dir, const struct qstr *qstr);
#else
static inline int ext3_init_security(handle_t *handle, struct inode *inode,
- struct inode *dir)
+ struct inode *dir, const struct qstr *qstr)
{
return 0;
}
diff --git a/fs/ext3/xattr_security.c b/fs/ext3/xattr_security.c
index 03a99bf..b8d9f83 100644
--- a/fs/ext3/xattr_security.c
+++ b/fs/ext3/xattr_security.c
@@ -49,14 +49,15 @@ ext3_xattr_security_set(struct dentry *dentry, const char *name,
}
int
-ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir)
+ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
int err;
size_t len;
void *value;
char *name;
- err = security_inode_init_security(inode, dir, &name, &value, &len);
+ err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
if (err) {
if (err == -EOPNOTSUPP)
return 0;
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 1ce240a..49b6cfd 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -1042,7 +1042,7 @@ got:
if (err)
goto fail_free_drop;
- err = ext4_init_security(handle, inode, dir);
+ err = ext4_init_security(handle, inode, dir, qstr);
if (err)
goto fail_free_drop;
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index 1ef1652..25b7387 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -145,10 +145,10 @@ ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
#ifdef CONFIG_EXT4_FS_SECURITY
extern int ext4_init_security(handle_t *handle, struct inode *inode,
- struct inode *dir);
+ struct inode *dir, const struct qstr *qstr);
#else
static inline int ext4_init_security(handle_t *handle, struct inode *inode,
- struct inode *dir)
+ struct inode *dir, const struct qstr *qstr)
{
return 0;
}
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 9b21268..007c3bf 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -49,14 +49,15 @@ ext4_xattr_security_set(struct dentry *dentry, const char *name,
}
int
-ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir)
+ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
int err;
size_t len;
void *value;
char *name;
- err = security_inode_init_security(inode, dir, &name, &value, &len);
+ err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
if (err) {
if (err == -EOPNOTSUPP)
return 0;
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index e1213f7..52fd31e 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -791,14 +791,15 @@ fail:
return error;
}
-static int gfs2_security_init(struct gfs2_inode *dip, struct gfs2_inode *ip)
+static int gfs2_security_init(struct gfs2_inode *dip, struct gfs2_inode *ip,
+ const struct qstr *qstr)
{
int err;
size_t len;
void *value;
char *name;
- err = security_inode_init_security(&ip->i_inode, &dip->i_inode,
+ err = security_inode_init_security(&ip->i_inode, &dip->i_inode, qstr,
&name, &value, &len);
if (err) {
@@ -882,7 +883,7 @@ struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,
if (error)
goto fail_gunlock2;
- error = gfs2_security_init(dip, GFS2_I(inode));
+ error = gfs2_security_init(dip, GFS2_I(inode), name);
if (error)
goto fail_gunlock2;
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index 9297865..82faddd 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -215,8 +215,7 @@ static int jffs2_create(struct inode *dir_i, struct dentry *dentry, int mode,
no chance of AB-BA deadlock involving its f->sem). */
mutex_unlock(&f->sem);
- ret = jffs2_do_create(c, dir_f, f, ri,
- dentry->d_name.name, dentry->d_name.len);
+ ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
if (ret)
goto fail;
@@ -386,7 +385,7 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char
jffs2_complete_reservation(c);
- ret = jffs2_init_security(inode, dir_i);
+ ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
if (ret)
goto fail;
@@ -530,7 +529,7 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int mode)
jffs2_complete_reservation(c);
- ret = jffs2_init_security(inode, dir_i);
+ ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
if (ret)
goto fail;
@@ -703,7 +702,7 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, de
jffs2_complete_reservation(c);
- ret = jffs2_init_security(inode, dir_i);
+ ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
if (ret)
goto fail;
diff --git a/fs/jffs2/nodelist.h b/fs/jffs2/nodelist.h
index 5a53d9b..e4619b0 100644
--- a/fs/jffs2/nodelist.h
+++ b/fs/jffs2/nodelist.h
@@ -401,7 +401,7 @@ int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
struct jffs2_raw_inode *ri, unsigned char *buf,
uint32_t offset, uint32_t writelen, uint32_t *retlen);
int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f,
- struct jffs2_raw_inode *ri, const char *name, int namelen);
+ struct jffs2_raw_inode *ri, const struct qstr *qstr);
int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, const char *name,
int namelen, struct jffs2_inode_info *dead_f, uint32_t time);
int jffs2_do_link(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, uint32_t ino,
diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c
index 239f512..cfeb716 100644
--- a/fs/jffs2/security.c
+++ b/fs/jffs2/security.c
@@ -23,14 +23,15 @@
#include "nodelist.h"
/* ---- Initial Security Label Attachment -------------- */
-int jffs2_init_security(struct inode *inode, struct inode *dir)
+int jffs2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
int rc;
size_t len;
void *value;
char *name;
- rc = security_inode_init_security(inode, dir, &name, &value, &len);
+ rc = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
if (rc) {
if (rc == -EOPNOTSUPP)
return 0;
diff --git a/fs/jffs2/write.c b/fs/jffs2/write.c
index c819eb0..30d175b 100644
--- a/fs/jffs2/write.c
+++ b/fs/jffs2/write.c
@@ -424,7 +424,9 @@ int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
return ret;
}
-int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f, struct jffs2_raw_inode *ri, const char *name, int namelen)
+int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f,
+ struct jffs2_inode_info *f, struct jffs2_raw_inode *ri,
+ const struct qstr *qstr)
{
struct jffs2_raw_dirent *rd;
struct jffs2_full_dnode *fn;
@@ -466,15 +468,15 @@ int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, str
mutex_unlock(&f->sem);
jffs2_complete_reservation(c);
- ret = jffs2_init_security(&f->vfs_inode, &dir_f->vfs_inode);
+ ret = jffs2_init_security(&f->vfs_inode, &dir_f->vfs_inode, qstr);
if (ret)
return ret;
ret = jffs2_init_acl_post(&f->vfs_inode);
if (ret)
return ret;
- ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
- ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
+ ret = jffs2_reserve_space(c, sizeof(*rd)+qstr->len, &alloclen,
+ ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(qstr->len));
if (ret) {
/* Eep. */
@@ -493,19 +495,19 @@ int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, str
rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
- rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
+ rd->totlen = cpu_to_je32(sizeof(*rd) + qstr->len);
rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
rd->pino = cpu_to_je32(dir_f->inocache->ino);
rd->version = cpu_to_je32(++dir_f->highest_version);
rd->ino = ri->ino;
rd->mctime = ri->ctime;
- rd->nsize = namelen;
+ rd->nsize = qstr->len;
rd->type = DT_REG;
rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
- rd->name_crc = cpu_to_je32(crc32(0, name, namelen));
+ rd->name_crc = cpu_to_je32(crc32(0, qstr->name, qstr->len));
- fd = jffs2_write_dirent(c, dir_f, rd, name, namelen, ALLOC_NORMAL);
+ fd = jffs2_write_dirent(c, dir_f, rd, qstr->name, qstr->len, ALLOC_NORMAL);
jffs2_free_raw_dirent(rd);
diff --git a/fs/jffs2/xattr.h b/fs/jffs2/xattr.h
index cf4f575..7be4beb 100644
--- a/fs/jffs2/xattr.h
+++ b/fs/jffs2/xattr.h
@@ -121,10 +121,11 @@ extern ssize_t jffs2_listxattr(struct dentry *, char *, size_t);
#endif /* CONFIG_JFFS2_FS_XATTR */
#ifdef CONFIG_JFFS2_FS_SECURITY
-extern int jffs2_init_security(struct inode *inode, struct inode *dir);
+extern int jffs2_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr);
extern const struct xattr_handler jffs2_security_xattr_handler;
#else
-#define jffs2_init_security(inode,dir) (0)
+#define jffs2_init_security(inode,dir,qstr) (0)
#endif /* CONFIG_JFFS2_FS_SECURITY */
#endif /* _JFFS2_FS_XATTR_H_ */
diff --git a/fs/jfs/jfs_xattr.h b/fs/jfs/jfs_xattr.h
index 88b6cc5..e9e100f 100644
--- a/fs/jfs/jfs_xattr.h
+++ b/fs/jfs/jfs_xattr.h
@@ -62,10 +62,11 @@ extern ssize_t jfs_listxattr(struct dentry *, char *, size_t);
extern int jfs_removexattr(struct dentry *, const char *);
#ifdef CONFIG_JFS_SECURITY
-extern int jfs_init_security(tid_t, struct inode *, struct inode *);
+extern int jfs_init_security(tid_t, struct inode *, struct inode *,
+ const struct qstr *);
#else
static inline int jfs_init_security(tid_t tid, struct inode *inode,
- struct inode *dir)
+ struct inode *dir, const struct qstr *qstr)
{
return 0;
}
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 231ca4a..ff0fda9 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -114,7 +114,7 @@ static int jfs_create(struct inode *dip, struct dentry *dentry, int mode,
if (rc)
goto out3;
- rc = jfs_init_security(tid, ip, dip);
+ rc = jfs_init_security(tid, ip, dip, &dentry->d_name);
if (rc) {
txAbort(tid, 0);
goto out3;
@@ -252,7 +252,7 @@ static int jfs_mkdir(struct inode *dip, struct dentry *dentry, int mode)
if (rc)
goto out3;
- rc = jfs_init_security(tid, ip, dip);
+ rc = jfs_init_security(tid, ip, dip, &dentry->d_name);
if (rc) {
txAbort(tid, 0);
goto out3;
@@ -931,7 +931,7 @@ static int jfs_symlink(struct inode *dip, struct dentry *dentry,
mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
- rc = jfs_init_security(tid, ip, dip);
+ rc = jfs_init_security(tid, ip, dip, &dentry->d_name);
if (rc)
goto out3;
@@ -1394,7 +1394,7 @@ static int jfs_mknod(struct inode *dir, struct dentry *dentry,
if (rc)
goto out3;
- rc = jfs_init_security(tid, ip, dir);
+ rc = jfs_init_security(tid, ip, dir, &dentry->d_name);
if (rc) {
txAbort(tid, 0);
goto out3;
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index 2d7f165..3fa4c32 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -1091,7 +1091,8 @@ int jfs_removexattr(struct dentry *dentry, const char *name)
}
#ifdef CONFIG_JFS_SECURITY
-int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir)
+int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
{
int rc;
size_t len;
@@ -1099,7 +1100,8 @@ int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir)
char *suffix;
char *name;
- rc = security_inode_init_security(inode, dir, &suffix, &value, &len);
+ rc = security_inode_init_security(inode, dir, qstr, &suffix, &value,
+ &len);
if (rc) {
if (rc == -EOPNOTSUPP)
return 0;
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index ff5744e..7740bc0 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -294,7 +294,7 @@ static int ocfs2_mknod(struct inode *dir,
}
/* get security xattr */
- status = ocfs2_init_security_get(inode, dir, &si);
+ status = ocfs2_init_security_get(inode, dir, &dentry->d_name, &si);
if (status) {
if (status == -EOPNOTSUPP)
si.enable = 0;
@@ -1665,7 +1665,7 @@ static int ocfs2_symlink(struct inode *dir,
}
/* get security xattr */
- status = ocfs2_init_security_get(inode, dir, &si);
+ status = ocfs2_init_security_get(inode, dir, &dentry->d_name, &si);
if (status) {
if (status == -EOPNOTSUPP)
si.enable = 0;
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index b5f9160..cd3f5b4 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4325,7 +4325,8 @@ static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
/* If the security isn't preserved, we need to re-initialize them. */
if (!preserve) {
- error = ocfs2_init_security_and_acl(dir, new_orphan_inode);
+ error = ocfs2_init_security_and_acl(dir, new_orphan_inode,
+ &new_dentry->d_name);
if (error)
mlog_errno(error);
}
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 67cd439..6bb6024 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -7185,7 +7185,8 @@ out:
* must not hold any lock expect i_mutex.
*/
int ocfs2_init_security_and_acl(struct inode *dir,
- struct inode *inode)
+ struct inode *inode,
+ const struct qstr *qstr)
{
int ret = 0;
struct buffer_head *dir_bh = NULL;
@@ -7193,7 +7194,7 @@ int ocfs2_init_security_and_acl(struct inode *dir,
.enable = 1,
};
- ret = ocfs2_init_security_get(inode, dir, &si);
+ ret = ocfs2_init_security_get(inode, dir, qstr, &si);
if (!ret) {
ret = ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_SECURITY,
si.name, si.value, si.value_len,
@@ -7261,13 +7262,14 @@ static int ocfs2_xattr_security_set(struct dentry *dentry, const char *name,
int ocfs2_init_security_get(struct inode *inode,
struct inode *dir,
+ const struct qstr *qstr,
struct ocfs2_security_xattr_info *si)
{
/* check whether ocfs2 support feature xattr */
if (!ocfs2_supports_xattr(OCFS2_SB(dir->i_sb)))
return -EOPNOTSUPP;
- return security_inode_init_security(inode, dir, &si->name, &si->value,
- &si->value_len);
+ return security_inode_init_security(inode, dir, qstr, &si->name,
+ &si->value, &si->value_len);
}
int ocfs2_init_security_set(handle_t *handle,
diff --git a/fs/ocfs2/xattr.h b/fs/ocfs2/xattr.h
index aa64bb3..d63cfb7 100644
--- a/fs/ocfs2/xattr.h
+++ b/fs/ocfs2/xattr.h
@@ -57,6 +57,7 @@ int ocfs2_has_inline_xattr_value_outside(struct inode *inode,
struct ocfs2_dinode *di);
int ocfs2_xattr_remove(struct inode *, struct buffer_head *);
int ocfs2_init_security_get(struct inode *, struct inode *,
+ const struct qstr *,
struct ocfs2_security_xattr_info *);
int ocfs2_init_security_set(handle_t *, struct inode *,
struct buffer_head *,
@@ -94,5 +95,6 @@ int ocfs2_reflink_xattrs(struct inode *old_inode,
struct buffer_head *new_bh,
bool preserve_security);
int ocfs2_init_security_and_acl(struct inode *dir,
- struct inode *inode);
+ struct inode *inode,
+ const struct qstr *qstr);
#endif /* OCFS2_XATTR_H */
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index ba5f51e..d5b22ed 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -593,7 +593,7 @@ static int reiserfs_create(struct inode *dir, struct dentry *dentry, int mode,
new_inode_init(inode, dir, mode);
jbegin_count += reiserfs_cache_default_acl(dir);
- retval = reiserfs_security_init(dir, inode, &security);
+ retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
if (retval < 0) {
drop_new_inode(inode);
return retval;
@@ -667,7 +667,7 @@ static int reiserfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
new_inode_init(inode, dir, mode);
jbegin_count += reiserfs_cache_default_acl(dir);
- retval = reiserfs_security_init(dir, inode, &security);
+ retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
if (retval < 0) {
drop_new_inode(inode);
return retval;
@@ -747,7 +747,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
new_inode_init(inode, dir, mode);
jbegin_count += reiserfs_cache_default_acl(dir);
- retval = reiserfs_security_init(dir, inode, &security);
+ retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
if (retval < 0) {
drop_new_inode(inode);
return retval;
@@ -1032,7 +1032,8 @@ static int reiserfs_symlink(struct inode *parent_dir,
}
new_inode_init(inode, parent_dir, mode);
- retval = reiserfs_security_init(parent_dir, inode, &security);
+ retval = reiserfs_security_init(parent_dir, inode, &dentry->d_name,
+ &security);
if (retval < 0) {
drop_new_inode(inode);
return retval;
diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
index 237c692..ef66c18 100644
--- a/fs/reiserfs/xattr_security.c
+++ b/fs/reiserfs/xattr_security.c
@@ -54,6 +54,7 @@ static size_t security_list(struct dentry *dentry, char *list, size_t list_len,
* of blocks needed for the transaction. If successful, reiserfs_security
* must be released using reiserfs_security_free when the caller is done. */
int reiserfs_security_init(struct inode *dir, struct inode *inode,
+ const struct qstr *qstr,
struct reiserfs_security_handle *sec)
{
int blocks = 0;
@@ -65,7 +66,7 @@ int reiserfs_security_init(struct inode *dir, struct inode *inode,
if (IS_PRIVATE(dir))
return 0;
- error = security_inode_init_security(inode, dir, &sec->name,
+ error = security_inode_init_security(inode, dir, qstr, &sec->name,
&sec->value, &sec->length);
if (error) {
if (error == -EOPNOTSUPP)
diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 94d5fd6..d9298cf 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -103,7 +103,8 @@ xfs_mark_inode_dirty(
STATIC int
xfs_init_security(
struct inode *inode,
- struct inode *dir)
+ struct inode *dir,
+ const struct qstr *qstr)
{
struct xfs_inode *ip = XFS_I(inode);
size_t length;
@@ -111,7 +112,7 @@ xfs_init_security(
unsigned char *name;
int error;
- error = security_inode_init_security(inode, dir, (char **)&name,
+ error = security_inode_init_security(inode, dir, qstr, (char **)&name,
&value, &length);
if (error) {
if (error == -EOPNOTSUPP)
@@ -195,7 +196,7 @@ xfs_vn_mknod(
inode = VFS_I(ip);
- error = xfs_init_security(inode, dir);
+ error = xfs_init_security(inode, dir, &dentry->d_name);
if (unlikely(error))
goto out_cleanup_inode;
@@ -368,7 +369,7 @@ xfs_vn_symlink(
inode = VFS_I(cip);
- error = xfs_init_security(inode, dir);
+ error = xfs_init_security(inode, dir, &dentry->d_name);
if (unlikely(error))
goto out_cleanup_inode;
diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h
index 6ce1bca..87312a8 100644
--- a/include/linux/ext3_fs.h
+++ b/include/linux/ext3_fs.h
@@ -874,7 +874,8 @@ extern int ext3fs_dirhash(const char *name, int len, struct
dx_hash_info *hinfo);
/* ialloc.c */
-extern struct inode * ext3_new_inode (handle_t *, struct inode *, int);
+extern struct inode * ext3_new_inode (handle_t *, struct inode *,
+ const struct qstr *, int);
extern void ext3_free_inode (handle_t *, struct inode *);
extern struct inode * ext3_orphan_get (struct super_block *, unsigned long);
extern unsigned long ext3_count_free_inodes (struct super_block *);
diff --git a/include/linux/reiserfs_xattr.h b/include/linux/reiserfs_xattr.h
index b2cf208..c2b7147 100644
--- a/include/linux/reiserfs_xattr.h
+++ b/include/linux/reiserfs_xattr.h
@@ -63,6 +63,7 @@ extern const struct xattr_handler reiserfs_xattr_trusted_handler;
extern const struct xattr_handler reiserfs_xattr_security_handler;
#ifdef CONFIG_REISERFS_FS_SECURITY
int reiserfs_security_init(struct inode *dir, struct inode *inode,
+ const struct qstr *qstr,
struct reiserfs_security_handle *sec);
int reiserfs_security_write(struct reiserfs_transaction_handle *th,
struct inode *inode,
@@ -130,6 +131,7 @@ static inline void reiserfs_init_xattr_rwsem(struct inode *inode)
#ifndef CONFIG_REISERFS_FS_SECURITY
static inline int reiserfs_security_init(struct inode *dir,
struct inode *inode,
+ const struct qstr *qstr,
struct reiserfs_security_handle *sec)
{
return 0;
diff --git a/include/linux/security.h b/include/linux/security.h
index 4ab684e..02fcc0e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -25,6 +25,7 @@
#include <linux/fs.h>
#include <linux/fsnotify.h>
#include <linux/binfmts.h>
+#include <linux/dcache.h>
#include <linux/signal.h>
#include <linux/resource.h>
#include <linux/sem.h>
@@ -315,6 +316,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* then it should return -EOPNOTSUPP to skip this processing.
* @inode contains the inode structure of the newly created inode.
* @dir contains the inode structure of the parent directory.
+ * @qstr contains the last path component of the new object
* @name will be set to the allocated name suffix (e.g. selinux).
* @value will be set to the allocated attribute value.
* @len will be set to the length of the value.
@@ -1437,7 +1439,8 @@ struct security_operations {
int (*inode_alloc_security) (struct inode *inode);
void (*inode_free_security) (struct inode *inode);
int (*inode_init_security) (struct inode *inode, struct inode *dir,
- char **name, void **value, size_t *len);
+ const struct qstr *qstr, char **name,
+ void **value, size_t *len);
int (*inode_create) (struct inode *dir,
struct dentry *dentry, int mode);
int (*inode_link) (struct dentry *old_dentry,
@@ -1701,7 +1704,8 @@ int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts);
int security_inode_alloc(struct inode *inode);
void security_inode_free(struct inode *inode);
int security_inode_init_security(struct inode *inode, struct inode *dir,
- char **name, void **value, size_t *len);
+ const struct qstr *qstr, char **name,
+ void **value, size_t *len);
int security_inode_create(struct inode *dir, struct dentry *dentry, int mode);
int security_inode_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry);
@@ -2028,6 +2032,7 @@ static inline void security_inode_free(struct inode *inode)
static inline int security_inode_init_security(struct inode *inode,
struct inode *dir,
+ const struct qstr *qstr,
char **name,
void **value,
size_t *len)
diff --git a/mm/shmem.c b/mm/shmem.c
index 47fdeeb..86cd21d 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1843,8 +1843,9 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
if (inode) {
- error = security_inode_init_security(inode, dir, NULL, NULL,
- NULL);
+ error = security_inode_init_security(inode, dir,
+ &dentry->d_name, NULL,
+ NULL, NULL);
if (error) {
if (error != -EOPNOTSUPP) {
iput(inode);
@@ -1983,8 +1984,8 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
if (!inode)
return -ENOSPC;
- error = security_inode_init_security(inode, dir, NULL, NULL,
- NULL);
+ error = security_inode_init_security(inode, dir, &dentry->d_name, NULL,
+ NULL, NULL);
if (error) {
if (error != -EOPNOTSUPP) {
iput(inode);
diff --git a/security/capability.c b/security/capability.c
index 92a1bff..c3d796c 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -118,7 +118,8 @@ static void cap_inode_free_security(struct inode *inode)
}
static int cap_inode_init_security(struct inode *inode, struct inode *dir,
- char **name, void **value, size_t *len)
+ const struct qstr *qstr, char **name,
+ void **value, size_t *len)
{
return -EOPNOTSUPP;
}
diff --git a/security/security.c b/security/security.c
index 799239d..7ebeb86 100644
--- a/security/security.c
+++ b/security/security.c
@@ -336,11 +336,13 @@ void security_inode_free(struct inode *inode)
}
int security_inode_init_security(struct inode *inode, struct inode *dir,
- char **name, void **value, size_t *len)
+ const struct qstr *qstr, char **name,
+ void **value, size_t *len)
{
if (unlikely(IS_PRIVATE(inode)))
return -EOPNOTSUPP;
- return security_ops->inode_init_security(inode, dir, name, value, len);
+ return security_ops->inode_init_security(inode, dir, qstr, name, value,
+ len);
}
EXPORT_SYMBOL(security_inode_init_security);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index b8dcd05..7699e23 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -39,6 +39,7 @@
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
+#include <linux/dcache.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/namei.h>
@@ -2509,8 +2510,8 @@ static void selinux_inode_free_security(struct inode *inode)
}
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
- char **name, void **value,
- size_t *len)
+ const struct qstr *qstr, char **name,
+ void **value, size_t *len)
{
const struct task_security_struct *tsec = current_security();
struct inode_security_struct *dsec;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 489a85a..581b65e 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -31,6 +31,7 @@
#include <net/cipso_ipv4.h>
#include <linux/audit.h>
#include <linux/magic.h>
+#include <linux/dcache.h>
#include "smack.h"
#define task_security(task) (task_cred_xxx((task), security))
@@ -424,6 +425,7 @@ static void smack_inode_free_security(struct inode *inode)
* smack_inode_init_security - copy out the smack from an inode
* @inode: the inode
* @dir: unused
+ * @qstr: unused
* @name: where to put the attribute name
* @value: where to put the attribute value
* @len: where to put the length of the attribute
@@ -431,7 +433,8 @@ static void smack_inode_free_security(struct inode *inode)
* Returns 0 if it all works out, -ENOMEM if there's no memory
*/
static int smack_inode_init_security(struct inode *inode, struct inode *dir,
- char **name, void **value, size_t *len)
+ const struct qstr *qstr, char **name,
+ void **value, size_t *len)
{
char *isp = smk_of_inode(inode);
>>>>> "Eric" == Eric Paris <[email protected]> writes:
Eric> SELinux would like to implement a new labeling behavior of newly
Eric> created inodes. We currently label new inodes based on the
Eric> parent and the creating process. This new behavior would also
Eric> take into account the name of the new object when deciding the
Eric> new label. This is not the (supposed) full path, just the last
Eric> component of the path.
Eric> This is very useful because creating /etc/shadow is different
Eric> than creating /etc/passwd but the kernel hooks are unable to
Eric> differentiate these operations. We currently require that
Eric> userspace realize it is doing some difficult operation like that
Eric> and than userspace jumps through SELinux hoops to get things set
Eric> up correctly. This patch does not implement new behavior, that
Eric> is obviously contained in a seperate SELinux patch, but it does
Eric> pass the needed name down to the correct LSM hook. If no such
Eric> name exists it is fine to pass NULL.
I've looked this patch over, and maybe I'm missing something, but how
does knowing the name of the file really tell you anything, esp when
you only get the filename, not the path? What threat are you
addressing with this change?
So what happens when I create a file /home/john/shadow, does selinux
(or LSM in general) then run extra checks because the filename is
'shadow' in your model?
I *think* the overhead shouldn't be there if SELINUX is disabled, but
have you confirmed this? How you run performance tests before/after
this change when doing lots of creations of inodes to see what sort of
performance changes might be there?
Thanks,
John
On Thu, 2010-12-09 at 10:05 -0500, John Stoffel wrote:
> >>>>> "Eric" == Eric Paris <[email protected]> writes:
> So what happens when I create a file /home/john/shadow, does selinux
> (or LSM in general) then run extra checks because the filename is
> 'shadow' in your model?
It's entirely a question of labeling and one that was discussed on the
LSM list in some detail:
http://marc.info/?t=129141308200002&r=1&w=2
The basic synopsis is that when a new inode is created SELinux must
apply some label. It makes the decision for what label to apply based
on 3 pieces of information.
The label of the parent inode.
The label of the process creating the new inode.
The 'class' of the inode, S_ISREG, S_ISDIR, S_ISLNK, etc
This patch adds a 4th piece of information, the name of the object being
created. An obvious situation where this will be useful is devtmpfs
(although you'll find other examples in the above thread). devtmpfs
when it creates char/block devices is unable to distinguish between kmem
and console and so they are created with a generic label. hotplug/udev
is then called which does some pathname like matching and relabels them
to something more specific. We've found that many people are able to
race against this particular updating and get spurious denials in /dev.
With this patch devtmpfs will be able to get the labels correct to begin
with.
I'm certainly willing to discuss the security implications of this
patch, but that would probably be best done with a significantly
shortened cc-list. You'll see in the above mentioned thread that a
number of 'security' people (even those who are staunchly anti-SELinux)
recognize there is value in this and that it is certainly much better
than we have today.
> I *think* the overhead shouldn't be there if SELINUX is disabled, but
> have you confirmed this? How you run performance tests before/after
> this change when doing lots of creations of inodes to see what sort of
> performance changes might be there?
I've actually recently done some perf testing on creating large numbers
of inodes using bonnie++, since SELinux was a noticeable overhead in
that operation. Doing that same test with SELinux disabled (or enabled)
I do not see a noticeable difference when this patch is applied or not.
It's just an extra argument to a function that goes unused.
-Eric
Quoting John Stoffel ([email protected]):
> >>>>> "Eric" == Eric Paris <[email protected]> writes:
>
> Eric> SELinux would like to implement a new labeling behavior of newly
> Eric> created inodes. We currently label new inodes based on the
> Eric> parent and the creating process. This new behavior would also
> Eric> take into account the name of the new object when deciding the
> Eric> new label. This is not the (supposed) full path, just the last
> Eric> component of the path.
>
> Eric> This is very useful because creating /etc/shadow is different
> Eric> than creating /etc/passwd but the kernel hooks are unable to
> Eric> differentiate these operations. We currently require that
> Eric> userspace realize it is doing some difficult operation like that
> Eric> and than userspace jumps through SELinux hoops to get things set
> Eric> up correctly. This patch does not implement new behavior, that
> Eric> is obviously contained in a seperate SELinux patch, but it does
> Eric> pass the needed name down to the correct LSM hook. If no such
> Eric> name exists it is fine to pass NULL.
>
> I've looked this patch over, and maybe I'm missing something, but how
> does knowing the name of the file really tell you anything, esp when
> you only get the filename, not the path? What threat are you
> addressing with this change?
Like you, I keep thinking back to this patch and going back and forth.
But to answer your question: in some cases, the name of the file
(plus the context of the directory in which it is created) can tell
you what assumptions userspace will make about it. And userspace most
definately is a part of the TCB, i.e. /bin/passwd and /bin/login.
-serge
>>>>> "Eric" == Eric Paris <[email protected]> writes:
Eric> On Thu, 2010-12-09 at 10:05 -0500, John Stoffel wrote:
>> >>>>> "Eric" == Eric Paris <[email protected]> writes:
>> So what happens when I create a file /home/john/shadow, does selinux
>> (or LSM in general) then run extra checks because the filename is
>> 'shadow' in your model?
Eric> It's entirely a question of labeling and one that was discussed on the
Eric> LSM list in some detail:
Eric> http://marc.info/?t=129141308200002&r=1&w=2
Thank you for pointing me at this discussion. I'm working my way
through it, but so far I'm not seeing any consensus that this is
really the proper thing to do. I personally feel this should be in
userspace if at all possible.
Eric> The basic synopsis is that when a new inode is created SELinux
Eric> must apply some label. It makes the decision for what label to
Eric> apply based on 3 pieces of information.
Eric> The label of the parent inode.
Eric> The label of the process creating the new inode.
Eric> The 'class' of the inode, S_ISREG, S_ISDIR, S_ISLNK, etc
These seem to be ok, if you're using label based security. But since
I freely admit I'm not an expert or even a user, I'm just trying to
understand and push back to make sure we do what's good. And which
doesn't impact non-SElinux users.
Eric> This patch adds a 4th piece of information, the name of the
Eric> object being created. An obvious situation where this will be
Eric> useful is devtmpfs (although you'll find other examples in the
Eric> above thread). devtmpfs when it creates char/block devices is
Eric> unable to distinguish between kmem and console and so they are
Eric> created with a generic label. hotplug/udev is then called which
Eric> does some pathname like matching and relabels them to something
Eric> more specific. We've found that many people are able to race
Eric> against this particular updating and get spurious denials in
Eric> /dev. With this patch devtmpfs will be able to get the labels
Eric> correct to begin with.
So your Label based access controls are *also* based on pathnames?
Right?
Eric> I'm certainly willing to discuss the security implications of this
Eric> patch, but that would probably be best done with a significantly
Eric> shortened cc-list. You'll see in the above mentioned thread that a
Eric> number of 'security' people (even those who are staunchly anti-SELinux)
Eric> recognize there is value in this and that it is certainly much better
Eric> than we have today.
>> I *think* the overhead shouldn't be there if SELINUX is disabled, but
>> have you confirmed this? How you run performance tests before/after
>> this change when doing lots of creations of inodes to see what sort of
>> performance changes might be there?
Eric> I've actually recently done some perf testing on creating large
Eric> numbers of inodes using bonnie++, since SELinux was a noticeable
Eric> overhead in that operation. Doing that same test with SELinux
Eric> disabled (or enabled) I do not see a noticeable difference when
Eric> this patch is applied or not. It's just an extra argument to a
Eric> function that goes unused.
That answers alot of my concerns then. Not having it impact users in
a non-SELinux context is vitally important to me.
Thanks,
John
On Thu, 2010-12-09 at 12:48 -0500, John Stoffel wrote:
> >>>>> "Eric" == Eric Paris <[email protected]> writes:
>
> Eric> On Thu, 2010-12-09 at 10:05 -0500, John Stoffel wrote:
> >> >>>>> "Eric" == Eric Paris <[email protected]> writes:
>
> Eric> This patch adds a 4th piece of information, the name of the
> Eric> object being created. An obvious situation where this will be
> Eric> useful is devtmpfs (although you'll find other examples in the
> Eric> above thread). devtmpfs when it creates char/block devices is
> Eric> unable to distinguish between kmem and console and so they are
> Eric> created with a generic label. hotplug/udev is then called which
> Eric> does some pathname like matching and relabels them to something
> Eric> more specific. We've found that many people are able to race
> Eric> against this particular updating and get spurious denials in
> Eric> /dev. With this patch devtmpfs will be able to get the labels
> Eric> correct to begin with.
>
> So your Label based access controls are *also* based on pathnames?
> Right?
Access decisions are still based solely on the label. This patch can
influence how new objects get their label, which makes the access
decisions indirectly path based. You'll find a reasonable summary and
commentary on lwn in this weeks security section.