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=-20.2 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, 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 F3AC6C433EF for ; Fri, 24 Sep 2021 12:47:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D81366124C for ; Fri, 24 Sep 2021 12:47:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344352AbhIXMt0 (ORCPT ); Fri, 24 Sep 2021 08:49:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:44324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344181AbhIXMsQ (ORCPT ); Fri, 24 Sep 2021 08:48:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E220A61261; Fri, 24 Sep 2021 12:46:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632487603; bh=i6QYdBqtc+JJTAEGfyXHvpk66/JLKkbfuHpzfb6jMxM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JhQMNzpYnMapitrITFudaUjfB40xKEDrhk31QycUAa3VhknXauSk828+D7y7U1SVN yO3aVhuwTWc/sjNCyRYqf9uQpf8VeTee2B0woe008PYlx13JcKP1Q68NNE9L82U3Lh RPbtg+cKXWz8E06rdG/g8wBKl/2S31h2/UFAfasw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Li Jinlin , Jens Axboe , Sasha Levin Subject: [PATCH 4.9 24/26] blk-throttle: fix UAF by deleteing timer in blk_throtl_exit() Date: Fri, 24 Sep 2021 14:44:12 +0200 Message-Id: <20210924124329.149547694@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210924124328.336953942@linuxfoundation.org> References: <20210924124328.336953942@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: Li Jinlin [ Upstream commit 884f0e84f1e3195b801319c8ec3d5774e9bf2710 ] The pending timer has been set up in blk_throtl_init(). However, the timer is not deleted in blk_throtl_exit(). This means that the timer handler may still be running after freeing the timer, which would result in a use-after-free. Fix by calling del_timer_sync() to delete the timer in blk_throtl_exit(). Signed-off-by: Li Jinlin Link: https://lore.kernel.org/r/20210907121242.2885564-1-lijinlin3@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-throttle.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 3a4c9a3c1427..6435dc25be0a 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1584,6 +1584,7 @@ int blk_throtl_init(struct request_queue *q) void blk_throtl_exit(struct request_queue *q) { BUG_ON(!q->td); + del_timer_sync(&q->td->service_queue.pending_timer); throtl_shutdown_wq(q); blkcg_deactivate_policy(q, &blkcg_policy_throtl); kfree(q->td); -- 2.33.0