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=-19.4 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 1C45FC47063 for ; Mon, 10 May 2021 11:21:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB67A61627 for ; Mon, 10 May 2021 11:21:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238823AbhEJLUI (ORCPT ); Mon, 10 May 2021 07:20:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:52164 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234007AbhEJKzo (ORCPT ); Mon, 10 May 2021 06:55:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3689B61C1F; Mon, 10 May 2021 10:43:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620643391; bh=YbwQKJAa9lOssjby/mnJkHTghR654Wic2HUcafAaiwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C2alBq5FJ1/N8V8trxvCEv1KduqvWoL3Aw9rwlH/b7Wi3l9vHFmc+jPBqhMoxgqXh ucYO+85LC7u7IyDRdCGqydiNyCVY3m2CxlT1xOxI/t9h3SR8lxlcRXYFZcS/tLZaxC IlBhhUuh9L6zY97Ared0xQ/YiaWd1CLphg9aOvcE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benjamin Block , Mike Snitzer Subject: [PATCH 5.10 296/299] dm rq: fix double free of blk_mq_tag_set in dev remove after table load fails Date: Mon, 10 May 2021 12:21:33 +0200 Message-Id: <20210510102014.707942849@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102004.821838356@linuxfoundation.org> References: <20210510102004.821838356@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: Benjamin Block commit 8e947c8f4a5620df77e43c9c75310dc510250166 upstream. When loading a device-mapper table for a request-based mapped device, and the allocation/initialization of the blk_mq_tag_set for the device fails, a following device remove will cause a double free. E.g. (dmesg): device-mapper: core: Cannot initialize queue for request-based dm-mq mapped device device-mapper: ioctl: unable to set up device queue for new table. Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0305e098835de000 TEID: 0305e098835de803 Fault in home space mode while using kernel ASCE. AS:000000025efe0007 R3:0000000000000024 Oops: 0038 ilc:3 [#1] SMP Modules linked in: ... lots of modules ... Supported: Yes, External CPU: 0 PID: 7348 Comm: multipathd Kdump: loaded Tainted: G W X 5.3.18-53-default #1 SLE15-SP3 Hardware name: IBM 8561 T01 7I2 (LPAR) Krnl PSW : 0704e00180000000 000000025e368eca (kfree+0x42/0x330) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 000000000000004a 000000025efe5230 c1773200d779968d 0000000000000000 000000025e520270 000000025e8d1b40 0000000000000003 00000007aae10000 000000025e5202a2 0000000000000001 c1773200d779968d 0305e098835de640 00000007a8170000 000003ff80138650 000000025e5202a2 000003e00396faa8 Krnl Code: 000000025e368eb8: c4180041e100 lgrl %r1,25eba50b8 000000025e368ebe: ecba06b93a55 risbg %r11,%r10,6,185,58 #000000025e368ec4: e3b010000008 ag %r11,0(%r1) >000000025e368eca: e310b0080004 lg %r1,8(%r11) 000000025e368ed0: a7110001 tmll %r1,1 000000025e368ed4: a7740129 brc 7,25e369126 000000025e368ed8: e320b0080004 lg %r2,8(%r11) 000000025e368ede: b904001b lgr %r1,%r11 Call Trace: [<000000025e368eca>] kfree+0x42/0x330 [<000000025e5202a2>] blk_mq_free_tag_set+0x72/0xb8 [<000003ff801316a8>] dm_mq_cleanup_mapped_device+0x38/0x50 [dm_mod] [<000003ff80120082>] free_dev+0x52/0xd0 [dm_mod] [<000003ff801233f0>] __dm_destroy+0x150/0x1d0 [dm_mod] [<000003ff8012bb9a>] dev_remove+0x162/0x1c0 [dm_mod] [<000003ff8012a988>] ctl_ioctl+0x198/0x478 [dm_mod] [<000003ff8012ac8a>] dm_ctl_ioctl+0x22/0x38 [dm_mod] [<000000025e3b11ee>] ksys_ioctl+0xbe/0xe0 [<000000025e3b127a>] __s390x_sys_ioctl+0x2a/0x40 [<000000025e8c15ac>] system_call+0xd8/0x2c8 Last Breaking-Event-Address: [<000000025e52029c>] blk_mq_free_tag_set+0x6c/0xb8 Kernel panic - not syncing: Fatal exception: panic_on_oops When allocation/initialization of the blk_mq_tag_set fails in dm_mq_init_request_queue(), it is uninitialized/freed, but the pointer is not reset to NULL; so when dev_remove() later gets into dm_mq_cleanup_mapped_device() it sees the pointer and tries to uninitialize and free it again. Fix this by setting the pointer to NULL in dm_mq_init_request_queue() error-handling. Also set it to NULL in dm_mq_cleanup_mapped_device(). Cc: # 4.6+ Fixes: 1c357a1e86a4 ("dm: allocate blk_mq_tag_set rather than embed in mapped_device") Signed-off-by: Benjamin Block Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-rq.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -569,6 +569,7 @@ out_tag_set: blk_mq_free_tag_set(md->tag_set); out_kfree_tag_set: kfree(md->tag_set); + md->tag_set = NULL; return err; } @@ -578,6 +579,7 @@ void dm_mq_cleanup_mapped_device(struct if (md->tag_set) { blk_mq_free_tag_set(md->tag_set); kfree(md->tag_set); + md->tag_set = NULL; } }