From: Ilya Dryomov <ilya.dryomov@xxxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit f2be82b0058e90b5d9ac2cb896b4914276fb50ef upstream. The check that makes sure that we have enough memory allocated to read in the entire header of the message in question is currently busted. It compares front_len of the incoming message with iov_len field of ceph_msg::front structure, which is used primarily to indicate the amount of data already read in, and not the size of the allocated buffer. Under certain conditions (e.g. a short read from a socket followed by that socket's shutdown and owning ceph_connection reset) this results in a warning similar to [85688.975866] libceph: get_reply front 198 > preallocated 122 (4#0) and, through another bug, leads to forever hung tasks and forced reboots. Fix this by comparing front_len with front_alloc_len field of struct ceph_msg, which stores the actual size of the buffer. Fixes: http://tracker.ceph.com/issues/5425 Signed-off-by: Ilya Dryomov <ilya.dryomov@xxxxxxxxxxx> Reviewed-by: Sage Weil <sage@xxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- net/ceph/messenger.c | 3 +-- net/ceph/osd_client.c | 4 ++-- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 30db7a69f061..464303f61730 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -3126,7 +3126,6 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags, INIT_LIST_HEAD(&m->data); /* front */ - m->front_alloc_len = front_len; if (front_len) { if (front_len > PAGE_CACHE_SIZE) { m->front.iov_base = __vmalloc(front_len, flags, @@ -3143,7 +3142,7 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags, } else { m->front.iov_base = NULL; } - m->front.iov_len = front_len; + m->front_alloc_len = m->front.iov_len = front_len; dout("ceph_msg_new %p front %d\n", m, front_len); return m; diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index 2efae981acd5..e6b2db68b4fa 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -2515,9 +2515,9 @@ static struct ceph_msg *get_reply(struct ceph_connection *con, req->r_reply, req->r_reply->con); ceph_msg_revoke_incoming(req->r_reply); - if (front_len > req->r_reply->front.iov_len) { + if (front_len > req->r_reply->front_alloc_len) { pr_warning("get_reply front %d > preallocated %d (%u#%llu)\n", - front_len, (int)req->r_reply->front.iov_len, + front_len, req->r_reply->front_alloc_len, (unsigned int)con->peer_name.type, le64_to_cpu(con->peer_name.num)); m = ceph_msg_new(CEPH_MSG_OSD_OPREPLY, front_len, GFP_NOFS, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html