Unverified Commit 8c6e03ff authored by Thorsten Blum's avatar Thorsten Blum Committed by Christian Brauner
Browse files

acl: Annotate struct posix_acl with __counted_by() 



Add the __counted_by compiler attribute to the flexible array member
a_entries to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Use struct_size() to calculate the number of bytes to allocate for new
and cloned acls and remove the local size variables.

Change the posix_acl_alloc() function parameter count from int to
unsigned int to match posix_acl's a_count data type. Add identifier
names to the function definition to silence two checkpatch warnings.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarThorsten Blum <thorsten.blum@linux.dev>
Link: https://lore.kernel.org/r/20241018121426.155247-2-thorsten.blum@linux.dev


Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 99bdadbd

fs/posix_acl.c

+6 −7
Original line number Diff line number Diff line
@@ -200,11 +200,11 @@ EXPORT_SYMBOL(posix_acl_init); 
 * Allocate a new ACL with the specified number of entries.

 */

struct posix_acl *

posix_acl_alloc(int count, gfp_t flags)

posix_acl_alloc(unsigned int count, gfp_t flags)

{

	const size_t size = sizeof(struct posix_acl) +

	                    count * sizeof(struct posix_acl_entry);

	struct posix_acl *acl = kmalloc(size, flags);

	struct posix_acl *acl;



	acl = kmalloc(struct_size(acl, a_entries, count), flags);

	if (acl)

		posix_acl_init(acl, count);

	return acl;
@@ -220,9 +220,8 @@ posix_acl_clone(const struct posix_acl *acl, gfp_t flags) 
	struct posix_acl *clone = NULL;



	if (acl) {

		int size = sizeof(struct posix_acl) + acl->a_count *

		           sizeof(struct posix_acl_entry);

		clone = kmemdup(acl, size, flags);

		clone = kmemdup(acl, struct_size(acl, a_entries, acl->a_count),

				flags);

		if (clone)

			refcount_set(&clone->a_refcount, 1);

	}

include/linux/posix_acl.h

+2 −2
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ struct posix_acl { 
	refcount_t		a_refcount;

	unsigned int		a_count;

	struct rcu_head		a_rcu;

	struct posix_acl_entry	a_entries[];

	struct posix_acl_entry	a_entries[] __counted_by(a_count);

};



#define FOREACH_ACL_ENTRY(pa, acl, pe) \
@@ -62,7 +62,7 @@ posix_acl_release(struct posix_acl *acl) 
/* posix_acl.c */



extern void posix_acl_init(struct posix_acl *, int);

extern struct posix_acl *posix_acl_alloc(int, gfp_t);

extern struct posix_acl *posix_acl_alloc(unsigned int count, gfp_t flags);

extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);

extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);

extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);