| From | Greg Kroah-Hartman <> | Subject | [ 166/171] libceph: avoid NULL kref_put when osd reset races with alloc_msg | Date | Wed, 21 Nov 2012 16:41:52 -0800 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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From: Sage Weil <sage@inktank.com>
(cherry picked from commit 9bd952615a42d7e2ce3fa2c632e808e804637a1a)
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@inktank.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ceph/messenger.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2746,7 +2746,8 @@ static int ceph_con_in_msg_alloc(struct 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;
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