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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADE2CC25B0E for ; Mon, 15 Aug 2022 19:55:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241289AbiHOTzZ (ORCPT ); Mon, 15 Aug 2022 15:55:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345468AbiHOTx2 (ORCPT ); Mon, 15 Aug 2022 15:53:28 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECD4E45982; Mon, 15 Aug 2022 11:51:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A218AB81057; Mon, 15 Aug 2022 18:51:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0C7DC433D6; Mon, 15 Aug 2022 18:51:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589497; bh=r2kVNVinlWkjZTWdJsscXrmKGXmHoK6A7xEXISd9w5I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BhQKH3n9dCOhbKx1wGmVbAn/xje7V/hIHJtZqtzNTc72nYnEPGnGQy6sZoxOFWshq 2fYGum1m5eflWYYlDxufRXMHVk6AJYrROJhtPKr39gijLHkumNbEXaX0+QJZFq8zz9 9vYktU85aKmFuu34XC8DNbXhRHCEEyHU9hM8tkRY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Mike Snitzer , Sasha Levin Subject: [PATCH 5.15 737/779] dm raid: fix address sanitizer warning in raid_status Date: Mon, 15 Aug 2022 20:06:21 +0200 Message-Id: <20220815180408.946194050@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@linuxfoundation.org> User-Agent: quilt/0.67 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: Mikulas Patocka [ Upstream commit 1fbeea217d8f297fe0e0956a1516d14ba97d0396 ] There is this warning when using a kernel with the address sanitizer and running this testsuite: https://gitlab.com/cki-project/kernel-tests/-/tree/main/storage/swraid/scsi_raid ================================================================== BUG: KASAN: slab-out-of-bounds in raid_status+0x1747/0x2820 [dm_raid] Read of size 4 at addr ffff888079d2c7e8 by task lvcreate/13319 CPU: 0 PID: 13319 Comm: lvcreate Not tainted 5.18.0-0.rc3. #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: dump_stack_lvl+0x6a/0x9c print_address_description.constprop.0+0x1f/0x1e0 print_report.cold+0x55/0x244 kasan_report+0xc9/0x100 raid_status+0x1747/0x2820 [dm_raid] dm_ima_measure_on_table_load+0x4b8/0xca0 [dm_mod] table_load+0x35c/0x630 [dm_mod] ctl_ioctl+0x411/0x630 [dm_mod] dm_ctl_ioctl+0xa/0x10 [dm_mod] __x64_sys_ioctl+0x12a/0x1a0 do_syscall_64+0x5b/0x80 The warning is caused by reading conf->max_nr_stripes in raid_status. The code in raid_status reads mddev->private, casts it to struct r5conf and reads the entry max_nr_stripes. However, if we have different raid type than 4/5/6, mddev->private doesn't point to struct r5conf; it may point to struct r0conf, struct r1conf, struct r10conf or struct mpconf. If we cast a pointer to one of these structs to struct r5conf, we will be reading invalid memory and KASAN warns about it. Fix this bug by reading struct r5conf only if raid type is 4, 5 or 6. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin --- drivers/md/dm-raid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index b0566aabc186..5f7e40c48e47 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3514,7 +3514,7 @@ static void raid_status(struct dm_target *ti, status_type_t type, { struct raid_set *rs = ti->private; struct mddev *mddev = &rs->md; - struct r5conf *conf = mddev->private; + struct r5conf *conf = rs_is_raid456(rs) ? mddev->private : NULL; int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0; unsigned long recovery; unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */ -- 2.35.1