[ 3.5.yuz extended stable ] Patch "libceph: avoid NULL kref_put when osd reset races with" has been added to staging queue

Herton Ronaldo Krzesinski herton.krzesinski at canonical.com
Tue Nov 20 17:19:44 UTC 2012

This is a note to let you know that I have just added a patch titled

    libceph: avoid NULL kref_put when osd reset races with

to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.yuz tree, see



>From c62b5860135c577cc9d950b2421506c236908c73 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage at inktank.com>
Date: Wed, 24 Oct 2012 16:12:58 -0700
Subject: [PATCH 74/78] libceph: avoid NULL kref_put when osd reset races with

commit 9bd952615a42d7e2ce3fa2c632e808e804637a1a upstream.

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 <sage at inktank.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
 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 0de041f..692243a 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2746,7 +2746,8 @@ static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
 		msg = con->ops->alloc_msg(con, hdr, skip);
 		if (con->state != CON_STATE_OPEN) {
-			ceph_msg_put(msg);
+			if (msg)
+				ceph_msg_put(msg);
 			return -EAGAIN;
 		con->in_msg = msg;

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