[3.11.y.z extended stable] Patch "libceph: potential NULL dereference in ceph_osdc_handle_map()" has been added to staging queue

[Luis Henriques]

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

    libceph: potential NULL dereference in ceph_osdc_handle_map()

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.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 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 4de1a38fc50f5520f0e545a99747e496ab29904e Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter at oracle.com>
Date: Thu, 15 Aug 2013 08:52:48 +0300
Subject: libceph: potential NULL dereference in ceph_osdc_handle_map()

commit b72e19b9225d4297a18715b0998093d843d170fa upstream.

There are two places where we read "nr_maps" if both of them are set to
zero then we would hit a NULL dereference here.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Reviewed-by: Sage Weil <sage at inktank.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ceph/osd_client.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 559a832..56f1fe5 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1786,6 +1786,8 @@ void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
 		nr_maps--;
 	}

+	if (!osdc->osdmap)
+		goto bad;
 done:
 	downgrade_write(&osdc->map_sem);
 	ceph_monc_got_osdmap(&osdc->client->monc, osdc->osdmap->epoch);
--
1.8.3.2