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Message-ID: <045f54ea-4057-43b8-81e2-5cc1b3966d04@schaufler-ca.com>
Date: Wed, 13 Mar 2024 08:56:12 -0700
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From: Casey Schaufler <casey@schaufler-ca.com>
Subject: [PATCH v2] LSM: use 32 bit compatible data types in LSM syscalls.
To: "Dmitry V. Levin" <ldv@strace.io>, Paul Moore <paul@paul-moore.com>,
 LSM List <linux-security-module@vger.kernel.org>
Cc: Linux kernel mailing list <linux-kernel@vger.kernel.org>,
 linux-api@vger.kernel.org, =?UTF-8?Q?Micka=C3=ABl_Sala=C3=BCn?=
 <mic@digikod.net>, James Morris <jmorris@namei.org>,
 Serge Hallyn <serge@hallyn.com>, John Johansen
 <john.johansen@canonical.com>,
 Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
 Stephen Smalley <stephen.smalley.work@gmail.com>,
 Casey Schaufler <casey@schaufler-ca.com>
References: <00734a64-a5fe-420c-bf6e-bee27c9d83be.ref@schaufler-ca.com>
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In-Reply-To: <00734a64-a5fe-420c-bf6e-bee27c9d83be.ref@schaufler-ca.com>
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LSM: use 32 bit compatible data types in LSM syscalls.

Change the size paramters in lsm_list_modules(), lsm_set_self_attr()
and lsm_get_self_attr() from size_t to u32. This avoids the need to
have different interfaces for 32 and 64 bit systems.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hook_defs.h                        |  4 ++--
 include/linux/security.h                             |  8 ++++----
 security/apparmor/lsm.c                              |  4 ++--
 security/lsm_syscalls.c                              | 10 +++++-----
 security/security.c                                  | 14 +++++++-------
 security/selinux/hooks.c                             |  4 ++--
 security/smack/smack_lsm.c                           |  4 ++--
 tools/testing/selftests/lsm/common.h                 |  6 +++---
 tools/testing/selftests/lsm/lsm_get_self_attr_test.c | 12 ++++++------
 tools/testing/selftests/lsm/lsm_list_modules_test.c  |  8 ++++----
 tools/testing/selftests/lsm/lsm_set_self_attr_test.c |  6 +++---
 11 files changed, 40 insertions(+), 40 deletions(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 76458b6d53da..f9b5baf1b5f4 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -265,9 +265,9 @@ LSM_HOOK(int, 0, netlink_send, struct sock *sk, struct sk_buff *skb)
 LSM_HOOK(void, LSM_RET_VOID, d_instantiate, struct dentry *dentry,
 	 struct inode *inode)
 LSM_HOOK(int, -EOPNOTSUPP, getselfattr, unsigned int attr,
-	 struct lsm_ctx __user *ctx, size_t *size, u32 flags)
+	 struct lsm_ctx __user *ctx, u32 *size, u32 flags)
 LSM_HOOK(int, -EOPNOTSUPP, setselfattr, unsigned int attr,
-	 struct lsm_ctx *ctx, size_t size, u32 flags)
+	 struct lsm_ctx *ctx, u32 size, u32 flags)
 LSM_HOOK(int, -EINVAL, getprocattr, struct task_struct *p, const char *name,
 	 char **value)
 LSM_HOOK(int, -EINVAL, setprocattr, const char *name, void *value, size_t size)
diff --git a/include/linux/security.h b/include/linux/security.h
index d0eb20f90b26..3180d823e023 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -478,9 +478,9 @@ int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops,
 			unsigned nsops, int alter);
 void security_d_instantiate(struct dentry *dentry, struct inode *inode);
 int security_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
-			 size_t __user *size, u32 flags);
+			 u32 __user *size, u32 flags);
 int security_setselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
-			 size_t size, u32 flags);
+			 u32 size, u32 flags);
 int security_getprocattr(struct task_struct *p, int lsmid, const char *name,
 			 char **value);
 int security_setprocattr(int lsmid, const char *name, void *value, size_t size);
@@ -494,7 +494,7 @@ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
 int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
 int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
 int security_locked_down(enum lockdown_reason what);
-int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, size_t *uctx_len,
+int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, u32 *uctx_len,
 		      void *val, size_t val_len, u64 id, u64 flags);
 #else /* CONFIG_SECURITY */
 
@@ -1434,7 +1434,7 @@ static inline int security_locked_down(enum lockdown_reason what)
 	return 0;
 }
 static inline int lsm_fill_user_ctx(struct lsm_ctx __user *uctx,
-				    size_t *uctx_len, void *val, size_t val_len,
+				    u32 *uctx_len, void *val, size_t val_len,
 				    u64 id, u64 flags)
 {
 	return -EOPNOTSUPP;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 9a3dcaafb5b1..cef8c466af80 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -779,7 +779,7 @@ static int apparmor_sb_pivotroot(const struct path *old_path,
 }
 
 static int apparmor_getselfattr(unsigned int attr, struct lsm_ctx __user *lx,
-				size_t *size, u32 flags)
+				u32 *size, u32 flags)
 {
 	int error = -ENOENT;
 	struct aa_task_ctx *ctx = task_ctx(current);
@@ -924,7 +924,7 @@ static int do_setattr(u64 attr, void *value, size_t size)
 }
 
 static int apparmor_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
-				size_t size, u32 flags)
+				u32 size, u32 flags)
 {
 	int rc;
 
diff --git a/security/lsm_syscalls.c b/security/lsm_syscalls.c
index 5d391b1f7e69..8440948a690c 100644
--- a/security/lsm_syscalls.c
+++ b/security/lsm_syscalls.c
@@ -53,7 +53,7 @@ u64 lsm_name_to_attr(const char *name)
  * value indicating the reason for the error is returned.
  */
 SYSCALL_DEFINE4(lsm_set_self_attr, unsigned int, attr, struct lsm_ctx __user *,
-		ctx, size_t, size, u32, flags)
+		ctx, u32, size, u32, flags)
 {
 	return security_setselfattr(attr, ctx, size, flags);
 }
@@ -75,7 +75,7 @@ SYSCALL_DEFINE4(lsm_set_self_attr, unsigned int, attr, struct lsm_ctx __user *,
  * a negative value indicating the error is returned.
  */
 SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *,
-		ctx, size_t __user *, size, u32, flags)
+		ctx, u32 __user *, size, u32, flags)
 {
 	return security_getselfattr(attr, ctx, size, flags);
 }
@@ -93,11 +93,11 @@ SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *,
  * required size. In all other cases a negative value indicating the
  * error is returned.
  */
-SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, size_t __user *, size,
+SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, u32 __user *, size,
 		u32, flags)
 {
-	size_t total_size = lsm_active_cnt * sizeof(*ids);
-	size_t usize;
+	u32 total_size = lsm_active_cnt * sizeof(*ids);
+	u32 usize;
 	int i;
 
 	if (flags)
diff --git a/security/security.c b/security/security.c
index 7035ee35a393..a0f9caf89ae1 100644
--- a/security/security.c
+++ b/security/security.c
@@ -785,7 +785,7 @@ static int lsm_superblock_alloc(struct super_block *sb)
  * Returns 0 on success, -E2BIG if userspace buffer is not large enough,
  * -EFAULT on a copyout error, -ENOMEM if memory can't be allocated.
  */
-int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, size_t *uctx_len,
+int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, u32 *uctx_len,
 		      void *val, size_t val_len,
 		      u64 id, u64 flags)
 {
@@ -810,7 +810,7 @@ int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, size_t *uctx_len,
 	nctx->ctx_len = val_len;
 	memcpy(nctx->ctx, val, val_len);
 
-	if (copy_to_user(uctx, nctx, nctx_len))
+	if (uctx && copy_to_user(uctx, nctx, nctx_len))
 		rc = -EFAULT;
 
 out:
@@ -3918,14 +3918,14 @@ EXPORT_SYMBOL(security_d_instantiate);
  * If @size is insufficient to contain the data -E2BIG is returned.
  */
 int security_getselfattr(unsigned int attr, struct lsm_ctx __user *uctx,
-			 size_t __user *size, u32 flags)
+			 u32 __user *size, u32 flags)
 {
 	struct security_hook_list *hp;
 	struct lsm_ctx lctx = { .id = LSM_ID_UNDEF, };
 	u8 __user *base = (u8 __user *)uctx;
-	size_t total = 0;
-	size_t entrysize;
-	size_t left;
+	u32 entrysize;
+	u32 total = 0;
+	u32 left;
 	bool toobig = false;
 	bool single = false;
 	int count = 0;
@@ -4011,7 +4011,7 @@ int security_getselfattr(unsigned int attr, struct lsm_ctx __user *uctx,
  * LSM specific failure.
  */
 int security_setselfattr(unsigned int attr, struct lsm_ctx __user *uctx,
-			 size_t size, u32 flags)
+			 u32 size, u32 flags)
 {
 	struct security_hook_list *hp;
 	struct lsm_ctx *lctx;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 338b023a8c3e..71e6e7079d7f 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6556,7 +6556,7 @@ static int selinux_lsm_setattr(u64 attr, void *value, size_t size)
  * There will only ever be one attribute.
  */
 static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
-			       size_t *size, u32 flags)
+			       u32 *size, u32 flags)
 {
 	int rc;
 	char *val = NULL;
@@ -6571,7 +6571,7 @@ static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
 }
 
 static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
-			       size_t size, u32 flags)
+			       u32 size, u32 flags)
 {
 	int rc;
 
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 0fdbf04cc258..0891fcc11e40 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3641,7 +3641,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
  * There will only ever be one attribute.
  */
 static int smack_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
-			     size_t *size, u32 flags)
+			     u32 *size, u32 flags)
 {
 	int rc;
 	struct smack_known *skp;
@@ -3762,7 +3762,7 @@ static int do_setattr(u64 attr, void *value, size_t size)
  * Returns 0 on success, an error code otherwise.
  */
 static int smack_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
-			     size_t size, u32 flags)
+			     u32 size, u32 flags)
 {
 	int rc;
 
diff --git a/tools/testing/selftests/lsm/common.h b/tools/testing/selftests/lsm/common.h
index d404329e5eeb..06d12110d241 100644
--- a/tools/testing/selftests/lsm/common.h
+++ b/tools/testing/selftests/lsm/common.h
@@ -7,7 +7,7 @@
 
 #ifndef lsm_get_self_attr
 static inline int lsm_get_self_attr(unsigned int attr, struct lsm_ctx *ctx,
-				    size_t *size, __u32 flags)
+				    __u32 *size, __u32 flags)
 {
 	return syscall(__NR_lsm_get_self_attr, attr, ctx, size, flags);
 }
@@ -15,14 +15,14 @@ static inline int lsm_get_self_attr(unsigned int attr, struct lsm_ctx *ctx,
 
 #ifndef lsm_set_self_attr
 static inline int lsm_set_self_attr(unsigned int attr, struct lsm_ctx *ctx,
-				    size_t size, __u32 flags)
+				    __u32 size, __u32 flags)
 {
 	return syscall(__NR_lsm_set_self_attr, attr, ctx, size, flags);
 }
 #endif
 
 #ifndef lsm_list_modules
-static inline int lsm_list_modules(__u64 *ids, size_t *size, __u32 flags)
+static inline int lsm_list_modules(__u64 *ids, __u32 *size, __u32 flags)
 {
 	return syscall(__NR_lsm_list_modules, ids, size, flags);
 }
diff --git a/tools/testing/selftests/lsm/lsm_get_self_attr_test.c b/tools/testing/selftests/lsm/lsm_get_self_attr_test.c
index e0e313d9047a..288302a444e0 100644
--- a/tools/testing/selftests/lsm/lsm_get_self_attr_test.c
+++ b/tools/testing/selftests/lsm/lsm_get_self_attr_test.c
@@ -40,7 +40,7 @@ TEST(size_null_lsm_get_self_attr)
 TEST(ctx_null_lsm_get_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
-	size_t size = page_size;
+	__u32 size = page_size;
 	int rc;
 
 	rc = lsm_get_self_attr(LSM_ATTR_CURRENT, NULL, &size, 0);
@@ -57,7 +57,7 @@ TEST(size_too_small_lsm_get_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	struct lsm_ctx *ctx = calloc(page_size, 1);
-	size_t size = 1;
+	__u32 size = 1;
 
 	ASSERT_NE(NULL, ctx);
 	errno = 0;
@@ -76,8 +76,8 @@ TEST(flags_zero_lsm_get_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	struct lsm_ctx *ctx = calloc(page_size, 1);
-	__u64 *syscall_lsms = calloc(page_size, 1);
-	size_t size;
+	__u32 *syscall_lsms = calloc(page_size, 1);
+	__u32 size;
 	int lsmcount;
 	int i;
 
@@ -117,7 +117,7 @@ TEST(flags_overset_lsm_get_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	struct lsm_ctx *ctx = calloc(page_size, 1);
-	size_t size;
+	__u32 size;
 
 	ASSERT_NE(NULL, ctx);
 
@@ -140,7 +140,7 @@ TEST(flags_overset_lsm_get_self_attr)
 TEST(basic_lsm_get_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
-	size_t size = page_size;
+	__u32 size = page_size;
 	struct lsm_ctx *ctx = calloc(page_size, 1);
 	struct lsm_ctx *tctx = NULL;
 	__u64 *syscall_lsms = calloc(page_size, 1);
diff --git a/tools/testing/selftests/lsm/lsm_list_modules_test.c b/tools/testing/selftests/lsm/lsm_list_modules_test.c
index 9df29b1e3497..868641dbb309 100644
--- a/tools/testing/selftests/lsm/lsm_list_modules_test.c
+++ b/tools/testing/selftests/lsm/lsm_list_modules_test.c
@@ -31,7 +31,7 @@ TEST(size_null_lsm_list_modules)
 TEST(ids_null_lsm_list_modules)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
-	size_t size = page_size;
+	__u32 size = page_size;
 
 	errno = 0;
 	ASSERT_EQ(-1, lsm_list_modules(NULL, &size, 0));
@@ -43,7 +43,7 @@ TEST(size_too_small_lsm_list_modules)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	__u64 *syscall_lsms = calloc(page_size, 1);
-	size_t size = 1;
+	__u32 size = 1;
 
 	ASSERT_NE(NULL, syscall_lsms);
 	errno = 0;
@@ -58,7 +58,7 @@ TEST(flags_set_lsm_list_modules)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	__u64 *syscall_lsms = calloc(page_size, 1);
-	size_t size = page_size;
+	__u32 size = page_size;
 
 	ASSERT_NE(NULL, syscall_lsms);
 	errno = 0;
@@ -72,7 +72,7 @@ TEST(flags_set_lsm_list_modules)
 TEST(correct_lsm_list_modules)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
-	size_t size = page_size;
+	__u32 size = page_size;
 	__u64 *syscall_lsms = calloc(page_size, 1);
 	char *sysfs_lsms = calloc(page_size, 1);
 	char *name;
diff --git a/tools/testing/selftests/lsm/lsm_set_self_attr_test.c b/tools/testing/selftests/lsm/lsm_set_self_attr_test.c
index e9712c6cf596..66dec47e3ca3 100644
--- a/tools/testing/selftests/lsm/lsm_set_self_attr_test.c
+++ b/tools/testing/selftests/lsm/lsm_set_self_attr_test.c
@@ -25,7 +25,7 @@ TEST(size_too_small_lsm_set_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	struct lsm_ctx *ctx = calloc(page_size, 1);
-	size_t size = page_size;
+	__u32 size = page_size;
 
 	ASSERT_NE(NULL, ctx);
 	if (attr_lsm_count()) {
@@ -41,7 +41,7 @@ TEST(flags_zero_lsm_set_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	struct lsm_ctx *ctx = calloc(page_size, 1);
-	size_t size = page_size;
+	__u32 size = page_size;
 
 	ASSERT_NE(NULL, ctx);
 	if (attr_lsm_count()) {
@@ -57,7 +57,7 @@ TEST(flags_overset_lsm_set_self_attr)
 {
 	const long page_size = sysconf(_SC_PAGESIZE);
 	char *ctx = calloc(page_size, 1);
-	size_t size = page_size;
+	__u32 size = page_size;
 	struct lsm_ctx *tctx = (struct lsm_ctx *)ctx;
 
 	ASSERT_NE(NULL, ctx);