[Ocfs2-devel] [PATCH] ocfs2: fix possible double free in ocfs2_reflink_xattr_rec

[Joseph Qi]

In ocfs2_reflink_xattr_rec(), meta_ac and data_ac are allocated by
calling ocfs2_lock_reflink_xattr_rec_allocators().
Once an error occurs when allocating *data_ac, it frees *meta_ac which
is allocated before. Here it mistakenly sets meta_ac to NULL but
*meta_ac. Then ocfs2_reflink_xattr_rec() will try to free meta_ac again
which is already invalid.

Signed-off-by: Joseph Qi <joseph.qi at huawei.com>
---
 fs/ocfs2/xattr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 87daa44..bd2a1f0 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -6799,7 +6799,7 @@ out:
 	if (ret) {
 		if (*meta_ac) {
 			ocfs2_free_alloc_context(*meta_ac);
-			meta_ac = NULL;
+			*meta_ac = NULL;
 		}
 	}

-- 
1.7.9.7