[3.16.y-ckt stable] Patch "Btrfs: fix kfree on list_head in btrfs_lookup_csums_range error cleanup" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Btrfs: fix kfree on list_head in btrfs_lookup_csums_range error cleanup

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 86acba1a164954b585f615171685e15c0902bd0b Mon Sep 17 00:00:00 2001
From: Chris Mason <clm at fb.com>
Date: Tue, 4 Nov 2014 06:59:04 -0800
Subject: Btrfs: fix kfree on list_head in btrfs_lookup_csums_range error
 cleanup

commit 6e5aafb27419f32575b27ef9d6a31e5d54661aca upstream.

If we hit any errors in btrfs_lookup_csums_range, we'll loop through all
the csums we allocate and free them.  But the code was using list_entry
incorrectly, and ended up trying to free the on-stack list_head instead.

This bug came from commit 0678b6185

btrfs: Don't BUG_ON kzalloc error in btrfs_lookup_csums_range()

Signed-off-by: Chris Mason <clm at fb.com>
Reported-by: Erik Berg <btrfs at slipsprogrammoer.no>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/btrfs/file-item.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 54c84daec9b5..74097722ad9f 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -423,7 +423,7 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
 	ret = 0;
 fail:
 	while (ret < 0 && !list_empty(&tmplist)) {
-		sums = list_entry(&tmplist, struct btrfs_ordered_sum, list);
+		sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
 		list_del(&sums->list);
 		kfree(sums);
 	}
--
2.1.0