From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE799C433B4 for ; Thu, 15 Apr 2021 15:07:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEDD661131 for ; Thu, 15 Apr 2021 15:07:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233983AbhDOPHv (ORCPT ); Thu, 15 Apr 2021 11:07:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:46150 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234743AbhDOO7e (ORCPT ); Thu, 15 Apr 2021 10:59:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1921261407; Thu, 15 Apr 2021 14:55:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618498545; bh=cQU0+XOWp0nJM700UOu15PgUUqFBCwBNwQGEhRmYy+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zTNs4jouX6vjcDfU9rshbhwTKxzXwCKkfL+beioy3cV8YpGhTN+tgiD76dve4PR6E Onl+RAVgBxy31uhBqRPI7YlzMXN2nyjToxcmL7eKQIZ81e6WKoHFkkeWH/Dbq8DQ3S kKyS0BpA5+GHANVH8PgYjB13YjXPjqLXErgTyszY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Saravana Kannan Subject: [PATCH 4.19 11/13] driver core: Fix locking bug in deferred_probe_timeout_work_func() Date: Thu, 15 Apr 2021 16:48:00 +0200 Message-Id: <20210415144411.970293701@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210415144411.596695196@linuxfoundation.org> References: <20210415144411.596695196@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Saravana Kannan commit eed6e41813deb9ee622cd9242341f21430d7789f upstream. list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list. Cc: stable@vger.kernel.org Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -254,14 +254,16 @@ int driver_deferred_probe_check_state(st static void deferred_probe_timeout_work_func(struct work_struct *work) { - struct device_private *private, *p; + struct device_private *p; deferred_probe_timeout = 0; driver_deferred_probe_trigger(); flush_work(&deferred_probe_work); - list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe) - dev_info(private->device, "deferred probe pending"); + mutex_lock(&deferred_probe_mutex); + list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe) + dev_info(p->device, "deferred probe pending\n"); + mutex_unlock(&deferred_probe_mutex); } static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);