From 9bd952615a42d7e2ce3fa2c632e808e804637a1a Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Wed, 24 Oct 2012 16:12:58 -0700 Subject: [PATCH] libceph: avoid NULL kref_put when osd reset races with alloc_msg The ceph_on_in_msg_alloc() method drops con->mutex while it allocates a message. If that races with a timeout that resends a zillion messages and resets the connection, and the ->alloc_msg() method returns a NULL message, it will call ceph_msg_put(NULL) and BUG. Fix by only calling put if msg is non-NULL. Fixes http://tracker.newdream.net/issues/3142 Signed-off-by: Sage Weil --- net/ceph/messenger.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index cad0d17ec45e..3ef1759403b4 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2750,7 +2750,8 @@ static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip) msg = con->ops->alloc_msg(con, hdr, skip); mutex_lock(&con->mutex); if (con->state != CON_STATE_OPEN) { - ceph_msg_put(msg); + if (msg) + ceph_msg_put(msg); return -EAGAIN; } con->in_msg = msg; -- 2.30.2