Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760708Ab2FHFjL (ORCPT ); Fri, 8 Jun 2012 01:39:11 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:59962 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756636Ab2FHFjI (ORCPT ); Fri, 8 Jun 2012 01:39:08 -0400 From: Ming Lei To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Ming Lei , Alan Stern , stable@vger.kernel.org Subject: [PATCH] driver core: fix shutdown races with probe/remove(v1) Date: Fri, 8 Jun 2012 13:38:49 +0800 Message-Id: <1339133929-30679-1-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1544 Lines: 51 Firstly, .shutdown callback may touch a uninitialized hardware if dev->driver is set and .probe is not completed. Secondly, device_shutdown() may dereference a null pointer to cause oops when dev->driver is cleared after it is checked in device_shutdown(). So just hold device lock and its parent lock if it has to fix the races. Cc: Alan Stern Cc: stable@vger.kernel.org Signed-off-by: Ming Lei --- drivers/base/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 346be8b..cbc8bd2 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1820,6 +1820,11 @@ void device_shutdown(void) list_del_init(&dev->kobj.entry); spin_unlock(&devices_kset->list_lock); + /*hold lock[s] to avoid races with .probe/.release*/ + if (dev->parent) + device_lock(dev->parent); + device_lock(dev); + /* Don't allow any more runtime suspends */ pm_runtime_get_noresume(dev); pm_runtime_barrier(dev); @@ -1831,6 +1836,9 @@ void device_shutdown(void) dev_dbg(dev, "shutdown\n"); dev->driver->shutdown(dev); } + device_unlock(dev); + if (dev->parent) + device_unlock(dev->parent); put_device(dev); spin_lock(&devices_kset->list_lock); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/