[ 12/24] ceph: Fix oops when handling mdsmap that decreases max_mds

Greg Kroah-Hartman
2012-11-02T17:12:19Z

From: "Yan, Zheng" <zheng.z.yan@intel.com>

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@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ceph/mds_client.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2625,7 +2625,8 @@ static void check_new_map(struct ceph_md
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) {