From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, "Yan, Zheng" , Sage Weil Subject: [ 12/24] ceph: Fix oops when handling mdsmap that decreases max_mds Date: Fri, 2 Nov 2012 10:07:00 -0700 Message-Id: <20121102170248.303699016@linuxfoundation.org> In-Reply-To: <20121102170247.406319110@linuxfoundation.org> References: <20121102170247.406319110@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Yan, Zheng" 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 Signed-off-by: Sage Weil Signed-off-by: Greg Kroah-Hartman --- 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) {