xfs: validate acl count

This prevents in-memory corruption and possible panics if the on-disk ACL is badly corrupted. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
mariux64 · Nov 29, 2011 · fa8b18e · fa8b18e
1 parent c889132
commit fa8b18e
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
@@ -42,6 +42,8 @@ xfs_acl_from_disk(struct xfs_acl *aclp)
 	int count, i;
 
 	count = be32_to_cpu(aclp->acl_cnt);
+	if (count > XFS_ACL_MAX_ENTRIES)
+		return ERR_PTR(-EFSCORRUPTED);
 
 	acl = posix_acl_alloc(count, GFP_KERNEL);
 	if (!acl)