From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754972Ab1JWGe0 (ORCPT ); Sun, 23 Oct 2011 02:34:26 -0400 Received: from cantor2.suse.de ([195.135.220.15]:40162 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754934Ab1JWGeX (ORCPT ); Sun, 23 Oct 2011 02:34:23 -0400 X-Mailbox-Line: From gregkh@pistachio.kroah.org Sun Oct 23 08:25:40 2011 Message-Id: <20111023062540.528834786@pistachio.kroah.org> User-Agent: quilt/0.48-16.4 Date: Sun, 23 Oct 2011 08:24:49 +0200 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: stable-review@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Chris Boot , Stefan Richter Subject: [21/27] firewire: sbp2: fix panic after rmmod with slow targets In-Reply-To: <20111023062833.GA8126@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let us know. ------------------ From: Chris Boot commit 0278ccd9d53e07c4e699432b2fed9de6c56f506c upstream. If firewire-sbp2 starts a login to a target that doesn't complete ORBs in a timely manner (and has to retry the login), and the module is removed before the operation times out, you end up with a null-pointer dereference and a kernel panic. [SR: This happens because sbp2_target_get/put() do not maintain module references. scsi_device_get/put() do, but at occasions like Chris describes one, nobody holds a reference to an SBP-2 sdev.] This patch cancels pending work for each unit in sbp2_remove(), which hopefully means there are no extra references around that prevent us from unloading. This fixes my crash. Signed-off-by: Chris Boot Signed-off-by: Stefan Richter Signed-off-by: Greg Kroah-Hartman --- drivers/firewire/sbp2.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/firewire/sbp2.c +++ b/drivers/firewire/sbp2.c @@ -1198,6 +1198,10 @@ static int sbp2_remove(struct device *de { struct fw_unit *unit = fw_unit(dev); struct sbp2_target *tgt = dev_get_drvdata(&unit->device); + struct sbp2_logical_unit *lu; + + list_for_each_entry(lu, &tgt->lu_list, link) + cancel_delayed_work_sync(&lu->work); sbp2_target_put(tgt); return 0;