From patchwork Tue Sep 7 12:12:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Jinlin X-Patchwork-Id: 12478381 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 BA5C8C433EF for ; Tue, 7 Sep 2021 11:43:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9255D61057 for ; Tue, 7 Sep 2021 11:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237399AbhIGLom (ORCPT ); Tue, 7 Sep 2021 07:44:42 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:15301 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229827AbhIGLoj (ORCPT ); Tue, 7 Sep 2021 07:44:39 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4H3k0j4mfVz8srh; Tue, 7 Sep 2021 19:43:01 +0800 (CST) Received: from dggema773-chm.china.huawei.com (10.1.198.217) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.8; Tue, 7 Sep 2021 19:43:30 +0800 Received: from localhost.huawei.com (10.175.124.27) by dggema773-chm.china.huawei.com (10.1.198.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Tue, 7 Sep 2021 19:43:29 +0800 From: Li Jinlin To: , CC: , , , , Subject: [PATCH] blk-throttle: fix UAF by deleteing timer in blk_throtl_exit() Date: Tue, 7 Sep 2021 20:12:42 +0800 Message-ID: <20210907121242.2885564-1-lijinlin3@huawei.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggema773-chm.china.huawei.com (10.1.198.217) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Li Jinlin 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 --- block/blk-throttle.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 55c49015e533..dbe49e181a88 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2458,6 +2458,7 @@ 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); free_percpu(q->td->latency_buckets[READ]);