Patch "btrfs: fix NULL pointer dereference from free_reloc_roots()" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

btrfs: fix NULL pointer dereference from free_reloc_roots()

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
btrfs-fix-null-pointer-dereference-from-free_reloc_roots.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Naohiro Aota <[email protected]>
Date: Fri, 25 Aug 2017 14:15:14 +0900
Subject: btrfs: fix NULL pointer dereference from free_reloc_roots()

From: Naohiro Aota <[email protected]>

commit bb166d7207432d3c7d10c45dc052f12ba3a2121d upstream.

__del_reloc_root should be called before freeing up reloc_root->node. If not, calling __del_reloc_root() dereference reloc_root->node, causing the system BUG.

---
 fs/btrfs/relocation.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -2350,11 +2350,11 @@ void free_reloc_roots(struct list_head *
 	while (!list_empty(list)) {
 		reloc_root = list_entry(list->next, struct btrfs_root,
 					root_list);
+		__del_reloc_root(reloc_root);
 		free_extent_buffer(reloc_root->node);
 		free_extent_buffer(reloc_root->commit_root);
 		reloc_root->node = NULL;
 		reloc_root->commit_root = NULL;
-		__del_reloc_root(reloc_root);
 	}
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/btrfs-propagate-error-to-btrfs_cmp_data_prepare-caller.patch queue-4.4/btrfs-fix-null-pointer-dereference-from-free_reloc_roots.patch