We've seen cases where people passed negative numbers to
posix_acl_alloc() and we fixed the caller. For example 093019cf1b "xfs:
fix acl count validation in xfs_acl_from_disk()". But there are other
places which might be affected like ext4_acl_from_disk() which checks
for negative but doesn't check an upper limit.
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index cea4623..cd7fd2f 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -46,7 +46,12 @@ posix_acl_alloc(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;
+
+ if (count < 0 || count > (SIZE_MAX - sizeof(struct posix_acl) /
+ sizeof(struct posix_acl_entry)))
+ return NULL;
+ acl = kmalloc(size, flags);
if (acl)
posix_acl_init(acl, count);
return acl;
--
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