lsm: use 32-bit compatible data types in LSM syscalls

Change the size parameters 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.

Cc: stable@vger.kernel.org
Fixes: a04a1198 ("LSM: syscalls for current process attributes")
Fixes: ad4aff9e ("LSM: Create lsm_list_modules system call")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-and-reviewed-by: Dmitry V. Levin <ldv@strace.io>
[PM: subject and metadata tweaks, syscall.h fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

include/linux/lsm_hook_defs.h

@@ -280,9 +280,9 @@ 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)

include/linux/security.h

@@ -491,9 +491,9 @@ 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);
@@ -507,7 +507,7 @@ 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 */
 
@@ -1478,7 +1478,7 @@ 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;

include/linux/syscalls.h

@@ -960,10 +960,10 @@ asmlinkage long sys_cachestat(unsigned int fd,
 		struct cachestat __user *cstat, unsigned int flags);
 asmlinkage long sys_map_shadow_stack(unsigned long addr, unsigned long size, unsigned int flags);
 asmlinkage long sys_lsm_get_self_attr(unsigned int attr, struct lsm_ctx *ctx,
-				      size_t *size, __u32 flags);
+				      u32 *size, u32 flags);
 asmlinkage long sys_lsm_set_self_attr(unsigned int attr, struct lsm_ctx *ctx,
-				      size_t size, __u32 flags);
-asmlinkage long sys_lsm_list_modules(u64 *ids, size_t *size, u32 flags);
+				      u32 size, u32 flags);
+asmlinkage long sys_lsm_list_modules(u64 *ids, u32 *size, u32 flags);
 
 /*
  * Architecture-specific system calls

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;
 

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)

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)
 {
@@ -3931,14 +3931,14 @@ 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;
@@ -4024,7 +4024,7 @@ 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;

security/selinux/hooks.c

@@ -6559,7 +6559,7 @@ 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;
@@ -6574,7 +6574,7 @@ 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;
 

security/smack/smack_lsm.c

@@ -3653,7 +3653,7 @@ 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;
@@ -3774,7 +3774,7 @@ 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;
 

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);
 }

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;
@@ -77,7 +77,7 @@ 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 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);

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;

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);