From: "Yan, Zheng" <zheng.z.yan@xxxxxxxxx> 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@xxxxxxxxx> --- 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 a5a7354..1bcf712 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -2625,7 +2625,8 @@ 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) { -- 1.7.11.4 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html