[3.16.y-ckt stable] Patch "Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref." 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:__add_inode_ref: out of bounds memory read when looking for extended ref.

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-ckt9.

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 028a0a83e2e2a0910adfe3e9a5f40b818056a8ed Mon Sep 17 00:00:00 2001
From: Quentin Casasnovas <quentin.casasnovas at oracle.com>
Date: Tue, 3 Mar 2015 16:31:38 +0100
Subject: Btrfs:__add_inode_ref: out of bounds memory read when looking for
 extended ref.

commit dd9ef135e3542ffc621c4eb7f0091870ec7a1504 upstream.

Improper arithmetics when calculting the address of the extended ref could
lead to an out of bounds memory read and kernel panic.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas at oracle.com>
Reviewed-by: David Sterba <dsterba at suse.cz>
Signed-off-by: Chris Mason <clm at fb.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/btrfs/tree-log.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 76bbe6557eb6..0a8194955e6b 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1007,7 +1007,7 @@ again:
 		base = btrfs_item_ptr_offset(leaf, path->slots[0]);

 		while (cur_offset < item_size) {
-			extref = (struct btrfs_inode_extref *)base + cur_offset;
+			extref = (struct btrfs_inode_extref *)(base + cur_offset);

 			victim_name_len = btrfs_inode_extref_name_len(leaf, extref);