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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C32BC433F5 for ; Wed, 13 Oct 2021 18:40:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 433A7610E8 for ; Wed, 13 Oct 2021 18:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238738AbhJMSmn (ORCPT ); Wed, 13 Oct 2021 14:42:43 -0400 Received: from mail-1.ca.inter.net ([208.85.220.69]:59798 "EHLO mail-1.ca.inter.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229967AbhJMSmm (ORCPT ); Wed, 13 Oct 2021 14:42:42 -0400 Received: from mp-mx11.ca.inter.net (mp-mx11.ca.inter.net [208.85.217.19]) by mail-1.ca.inter.net (Postfix) with ESMTP id E45392EAA0E; Wed, 13 Oct 2021 14:40:37 -0400 (EDT) Received: from mail-1.ca.inter.net ([208.85.220.69]) by mp-mx11.ca.inter.net (mp-mx11.ca.inter.net [208.85.217.19]) (amavisd-new, port 10024) with ESMTP id gzAhiMfkuP1q; Wed, 13 Oct 2021 14:40:37 -0400 (EDT) Received: from [192.168.48.23] (host-23-91-187-47.dyn.295.ca [23.91.187.47]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: dgilbert@interlog.com) by mail-1.ca.inter.net (Postfix) with ESMTPSA id 4551A2EA530; Wed, 13 Oct 2021 14:40:37 -0400 (EDT) Reply-To: dgilbert@interlog.com Subject: Re: [PATCH v2 resend 1/2] scsi:scsi_debug: Fix out-of-bound read in resp_readcap16 To: Ye Bin , jejb@linux.ibm.com, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, bvanassche@acm.org References: <20211013033913.2551004-1-yebin10@huawei.com> <20211013033913.2551004-2-yebin10@huawei.com> From: Douglas Gilbert Message-ID: <7f2622fe-de37-525a-5f93-961b510e1389@interlog.com> Date: Wed, 13 Oct 2021 14:40:37 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20211013033913.2551004-2-yebin10@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-CA Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-10-12 11:39 p.m., Ye Bin wrote: > We got following warning when runing 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 > > We can reproduce this issue with 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) > > As in resp_readcap16 we get "int alloc_len" value -1104926854, and then pass > huge arr_len to fill_from_dev_buffer, but arr is only has 32 bytes space. So > lead to OOB in sg_copy_buffer. > To solve this issue just define alloc_len with U32 type. > > Signed-off-by: Ye Bin Acked-by: Douglas Gilbert Thanks. > --- > 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 66f507469a31..be0440545744 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 >