From 73bba6fc44591587254fec8e867a99b5a2a28ba7 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 20 Sep 2012 17:42:25 +0800 Subject: ceph: Fix oops when handling mdsmap that decreases max_mds (cherry picked from commit 3e8f43a089f06279c5f76a9ccd42578eebf7bfa5) 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 Signed-off-by: Sage Weil Signed-off-by: Greg Kroah-Hartman --- 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 5ac6434185a..7f1682da29a 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) { -- cgit v1.2.3