[ 3.5.yuz extended stable ] Patch "ceph: Fix oops when handling mdsmap that decreases" has been added to staging queue

[Herton Ronaldo Krzesinski]

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

    ceph: Fix oops when handling mdsmap that decreases

to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

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

For more information about the 3.5.yuz tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 838edc050d32d511cbf30df783dcc9e6041b5fad Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zheng.z.yan at intel.com>
Date: Thu, 20 Sep 2012 17:42:25 +0800
Subject: [PATCH 76/78] ceph: Fix oops when handling mdsmap that decreases
 max_mds

commit 3e8f43a089f06279c5f76a9ccd42578eebf7bfa5 upstream.

When i >= newmap->m_max_mds, ceph_mdsmap_get_addr(newmap, i) return
NULL. Passing NULL to memcmp() triggers oops.

Signed-off-by: Yan, Zheng <zheng.z.yan at intel.com>
Signed-off-by: Sage Weil <sage at inktank.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 fs/ceph/mds_client.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 5ac6434..7f1682d 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2634,7 +2634,8 @@ static void check_new_map(struct ceph_mds_client *mdsc,
 		     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
 		     session_state_name(s->s_state));

-		if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
+		if (i >= newmap->m_max_mds ||
+		    memcmp(ceph_mdsmap_get_addr(oldmap, i),
 			   ceph_mdsmap_get_addr(newmap, i),
 			   sizeof(struct ceph_entity_addr))) {
 			if (s->s_state == CEPH_MDS_SESSION_OPENING) {
--
1.7.9.5