[PATCH 3.11 119/208] libceph: potential NULL dereference in ceph_osdc_handle_map()

[Luis Henriques]

3.11.10.3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter at oracle.com>

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