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 85E9EC433F5 for ; Wed, 13 Oct 2021 18:40:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6515D610E8 for ; Wed, 13 Oct 2021 18:40:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238670AbhJMSmi (ORCPT ); Wed, 13 Oct 2021 14:42:38 -0400 Received: from mail-1.ca.inter.net ([208.85.220.69]:59760 "EHLO mail-1.ca.inter.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229967AbhJMSmg (ORCPT ); Wed, 13 Oct 2021 14:42:36 -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 BFFB32EA525; Wed, 13 Oct 2021 14:40:31 -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 gmdedJn2uhmy; Wed, 13 Oct 2021 14:40:31 -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 B3C7E2EA078; Wed, 13 Oct 2021 14:40:30 -0400 (EDT) Reply-To: dgilbert@interlog.com Subject: Re: [PATCH v2 resend 2/2] scsi:scsi_debug:Fix out-of-bound read in resp_report_tgtpgs 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> <20211013033913.2551004-3-yebin10@huawei.com> From: Douglas Gilbert Message-ID: Date: Wed, 13 Oct 2021 14:40:29 -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: <20211013033913.2551004-3-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 follow issue when run syzkaller: > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:377 [inline] > BUG: KASAN: slab-out-of-bounds in sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831 > Read of size 2132 at addr ffff8880aea95dc8 by task syz-executor.0/9815 > > CPU: 0 PID: 9815 Comm: syz-executor.0 Not tainted 4.19.202-00874-gfc0fe04215a9 #2 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xe4/0x14a lib/dump_stack.c:118 > print_address_description+0x73/0x280 mm/kasan/report.c:253 > kasan_report_error mm/kasan/report.c:352 [inline] > kasan_report+0x272/0x370 mm/kasan/report.c:410 > memcpy+0x1f/0x50 mm/kasan/kasan.c:302 > memcpy include/linux/string.h:377 [inline] > sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831 > fill_from_dev_buffer+0x14f/0x340 drivers/scsi/scsi_debug.c:1021 > resp_report_tgtpgs+0x5aa/0x770 drivers/scsi/scsi_debug.c:1772 > schedule_resp+0x464/0x12f0 drivers/scsi/scsi_debug.c:4429 > scsi_debug_queuecommand+0x467/0x1390 drivers/scsi/scsi_debug.c:5835 > scsi_dispatch_cmd+0x3fc/0x9b0 drivers/scsi/scsi_lib.c:1896 > scsi_request_fn+0x1042/0x1810 drivers/scsi/scsi_lib.c:2034 > __blk_run_queue_uncond block/blk-core.c:464 [inline] > __blk_run_queue+0x1a4/0x380 block/blk-core.c:484 > blk_execute_rq_nowait+0x1c2/0x2d0 block/blk-exec.c:78 > sg_common_write.isra.19+0xd74/0x1dc0 drivers/scsi/sg.c:847 > sg_write.part.23+0x6e0/0xd00 drivers/scsi/sg.c:716 > sg_write+0x64/0xa0 drivers/scsi/sg.c:622 > __vfs_write+0xed/0x690 fs/read_write.c:485 > kill_bdev:block_device:00000000e138492c > vfs_write+0x184/0x4c0 fs/read_write.c:549 > ksys_write+0x107/0x240 fs/read_write.c:599 > do_syscall_64+0xc2/0x560 arch/x86/entry/common.c:293 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > As with previous patch, we get 'alen' from command, and 'alen''s type is > int, If userspace pass large length we will get negative 'alen'. > So just set 'n'/'alen'/'rlen' with u32 type. > > Signed-off-by: Ye Bin Acked-by: Douglas Gilbert Thanks. > --- > drivers/scsi/scsi_debug.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c > index be0440545744..ead65cdfb522 100644 > --- a/drivers/scsi/scsi_debug.c > +++ b/drivers/scsi/scsi_debug.c > @@ -1896,8 +1896,9 @@ static int resp_report_tgtpgs(struct scsi_cmnd *scp, > unsigned char *cmd = scp->cmnd; > unsigned char *arr; > int host_no = devip->sdbg_host->shost->host_no; > - int n, ret, alen, rlen; > int port_group_a, port_group_b, port_a, port_b; > + u32 alen, n, rlen; > + int ret; > > alen = get_unaligned_be32(cmd + 6); > arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_ATOMIC); > @@ -1959,9 +1960,9 @@ static int resp_report_tgtpgs(struct scsi_cmnd *scp, > * - The constructed command length > * - The maximum array size > */ > - rlen = min_t(int, alen, n); > + rlen = min(alen, n); > ret = fill_from_dev_buffer(scp, arr, > - min_t(int, rlen, SDEBUG_MAX_TGTPGS_ARR_SZ)); > + min_t(u32, rlen, SDEBUG_MAX_TGTPGS_ARR_SZ)); > kfree(arr); > return ret; > } >