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 3C47DC433F5 for ; Wed, 24 Nov 2021 13:48:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350018AbhKXNvr (ORCPT ); Wed, 24 Nov 2021 08:51:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:37488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344044AbhKXNrB (ORCPT ); Wed, 24 Nov 2021 08:47:01 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 942776120A; Wed, 24 Nov 2021 13:01:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637758880; bh=JhgAtN774Pou7HOw4OaGDPO929cZub21tWdavgvxMMs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cBc1oMh6HSMFXfoCJY13p69uO/zIva5ZtPUrsigkT3+Xo2kFAlqNbJ36LFOiWZKKH ZRuPK49nrk8SvbPpOyfu/wolS0lCm06vi8S+bVssj94huuL8TDx9MCOMZcOkSM2B3F xBoiKiSxdndeyr6xMM50n/vnx2FFOjq2YIL6oBe0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Douglas Gilbert , Ye Bin , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 5.15 061/279] scsi: scsi_debug: Fix out-of-bound read in resp_readcap16() Date: Wed, 24 Nov 2021 12:55:48 +0100 Message-Id: <20211124115720.825384760@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115718.776172708@linuxfoundation.org> References: <20211124115718.776172708@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: Ye Bin [ Upstream commit 4e3ace0051e7e504b55d239daab8789dd89b863c ] The following warning was observed running syzkaller: [ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in; [ 3813.830724] program syz-executor not setting count and/or reply_len properly [ 3813.836956] ================================================================== [ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0 [ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549 [ 3813.846612] Call Trace: [ 3813.846995] dump_stack+0x108/0x15f [ 3813.847524] print_address_description+0xa5/0x372 [ 3813.848243] kasan_report.cold+0x236/0x2a8 [ 3813.849439] check_memory_region+0x240/0x270 [ 3813.850094] memcpy+0x30/0x80 [ 3813.850553] sg_copy_buffer+0x157/0x1e0 [ 3813.853032] sg_copy_from_buffer+0x13/0x20 [ 3813.853660] fill_from_dev_buffer+0x135/0x370 [ 3813.854329] resp_readcap16+0x1ac/0x280 [ 3813.856917] schedule_resp+0x41f/0x1630 [ 3813.858203] scsi_debug_queuecommand+0xb32/0x17e0 [ 3813.862699] scsi_dispatch_cmd+0x330/0x950 [ 3813.863329] scsi_request_fn+0xd8e/0x1710 [ 3813.863946] __blk_run_queue+0x10b/0x230 [ 3813.864544] blk_execute_rq_nowait+0x1d8/0x400 [ 3813.865220] sg_common_write.isra.0+0xe61/0x2420 [ 3813.871637] sg_write+0x6c8/0xef0 [ 3813.878853] __vfs_write+0xe4/0x800 [ 3813.883487] vfs_write+0x17b/0x530 [ 3813.884008] ksys_write+0x103/0x270 [ 3813.886268] __x64_sys_write+0x77/0xc0 [ 3813.886841] do_syscall_64+0x106/0x360 [ 3813.887415] entry_SYSCALL_64_after_hwframe+0x44/0xa9 This issue can be reproduced with the following syzkaller log: r0 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x26e1, 0x0) r1 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='fd/3\x00') open_by_handle_at(r1, &(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000) r2 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x40782) write$binfmt_aout(r2, &(0x7f0000000340)=ANY=[@ANYBLOB="00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d"], 0x126) In resp_readcap16() we get "int alloc_len" value -1104926854, and then pass the huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This leads to OOB in sg_copy_buffer(). To solve this issue, define alloc_len as u32. Link: https://lore.kernel.org/r/20211013033913.2551004-2-yebin10@huawei.com Acked-by: Douglas Gilbert Signed-off-by: Ye Bin Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/scsi_debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 66f507469a31a..be04405457447 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -1856,7 +1856,7 @@ static int resp_readcap16(struct scsi_cmnd *scp, { unsigned char *cmd = scp->cmnd; unsigned char arr[SDEBUG_READCAP16_ARR_SZ]; - int alloc_len; + u32 alloc_len; alloc_len = get_unaligned_be32(cmd + 10); /* following just in case virtual_gb changed */ @@ -1885,7 +1885,7 @@ static int resp_readcap16(struct scsi_cmnd *scp, } return fill_from_dev_buffer(scp, arr, - min_t(int, alloc_len, SDEBUG_READCAP16_ARR_SZ)); + min_t(u32, alloc_len, SDEBUG_READCAP16_ARR_SZ)); } #define SDEBUG_MAX_TGTPGS_ARR_SZ 1412 -- 2.33.0