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ocfs2: fix possible double free in ocfs2_reflink_xattr_rec

PATCH New Joseph Qi 2 participants 2 messages Aug 2, 2013 – Aug 6, 2013 OCFS2

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Joseph Qi

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#0 lore raw

PATCH 1/1 ocfs2: fix possible double free in ocfs2_reflink_xattr_rec

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.

---
 fs/ocfs2/xattr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
fs/ocfs2/xattr.c +1 -1
index 87daa44..bd2a1f0 100644
@@ -6799,7 +6799,7 @@ out:
 	if (ret) {
 		if (*meta_ac) {
 			ocfs2_free_alloc_context(*meta_ac);
-			meta_ac = NULL;
+			*meta_ac = NULL;
 		}
 	}
 
Signature · 1 line
1.7.9.7
#1 lore raw

PATCH 1/1 ocfs2: fix possible double free in ocfs2_reflink_xattr_rec

Quoted 8 lines · 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.

Looks good to me, thanks.

Quoted 17 lines
---
 fs/ocfs2/xattr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
fs/ocfs2/xattr.c +1 -1
index 87daa44..bd2a1f0 100644
@@ -6799,7 +6799,7 @@ out:
 	if (ret) {
 		if (*meta_ac) {
 			ocfs2_free_alloc_context(*meta_ac);
-			meta_ac = NULL;
+			*meta_ac = NULL;
 		}
 	}