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=-19.0 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 7F2B8C433E3 for ; Mon, 22 Mar 2021 12:40:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B415619EF for ; Mon, 22 Mar 2021 12:40:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231379AbhCVMjw (ORCPT ); Mon, 22 Mar 2021 08:39:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:56134 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231685AbhCVMem (ORCPT ); Mon, 22 Mar 2021 08:34:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 868836191A; Mon, 22 Mar 2021 12:34:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1616416482; bh=z3f1V9uZjD/V19KIeAUNsK2dX+kH3ujXiRjv4WcmBXg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yvzQFQHPsS2Wms8mSFqcHonbRLkfcmIAKUDiqSQ5nhsRdY1cpc4xqApdMNuyZ3dLk DLtjo4gKfZ9A7GsAfaPpv/sUfOt5M0y4GqalEPtJ8iuiy7/YWknxBZB7yUcVlYG8YN mzKlEaBLBfqPR600p7vYmnTlou566Bux6gFZRfLc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+628472a2aac693ab0fcd@syzkaller.appspotmail.com, Jan Kara , Theodore Tso Subject: [PATCH 5.11 112/120] ext4: fix timer use-after-free on failed mount Date: Mon, 22 Mar 2021 13:28:15 +0100 Message-Id: <20210322121933.396744528@linuxfoundation.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210322121929.669628946@linuxfoundation.org> References: <20210322121929.669628946@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: Jan Kara commit 2a4ae3bcdf05b8639406eaa09a2939f3c6dd8e75 upstream. When filesystem mount fails because of corrupted filesystem we first cancel the s_err_report timer reminding fs errors every day and only then we flush s_error_work. However s_error_work may report another fs error and re-arm timer thus resulting in timer use-after-free. Fix the problem by first flushing the work and only after that canceling the s_err_report timer. Reported-by: syzbot+628472a2aac693ab0fcd@syzkaller.appspotmail.com Fixes: 2d01ddc86606 ("ext4: save error info to sb through journal if available") CC: stable@vger.kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20210315165906.2175-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5149,8 +5149,8 @@ failed_mount_wq: failed_mount3a: ext4_es_unregister_shrinker(sbi); failed_mount3: - del_timer_sync(&sbi->s_err_report); flush_work(&sbi->s_error_work); + del_timer_sync(&sbi->s_err_report); if (sbi->s_mmp_tsk) kthread_stop(sbi->s_mmp_tsk); failed_mount2: