From patchwork Wed Jul 20 02:51:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 592083 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 C2010C433EF for ; Wed, 20 Jul 2022 02:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239146AbiGTCjP (ORCPT ); Tue, 19 Jul 2022 22:39:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238975AbiGTCjO (ORCPT ); Tue, 19 Jul 2022 22:39:14 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFF6C6E893; Tue, 19 Jul 2022 19:39:11 -0700 (PDT) Received: from canpemm500004.china.huawei.com (unknown [172.30.72.53]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Lnfw95TWKz1M89f; Wed, 20 Jul 2022 10:36:25 +0800 (CST) Received: from huawei.com (10.175.127.227) by canpemm500004.china.huawei.com (7.192.104.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 20 Jul 2022 10:39:08 +0800 From: Jason Yan To: , CC: , , , , , Jason Yan , Subject: [PATCH v2] scsi: fix WARNING in scsi_alloc_sgtables Date: Wed, 20 Jul 2022 10:51:20 +0800 Message-ID: <20220720025120.3226770-1-yanaijie@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500004.china.huawei.com (7.192.104.92) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org As explained in SG_IO howto[1]: "If iovec_count is non-zero then 'dxfer_len' should be equal to the sum of iov_len lengths. If not, the minimum of the two is the transfer length." When iovec_count is non-zero and dxfer_len is zero, the sg_io() just genarated a null bio, and finally caused a warning below. To fix it, skip generating a bio for this request if dxfer_len is zero. [1] https://tldp.org/HOWTO/SCSI-Generic-HOWTO/x198.html WARNING: CPU: 2 PID: 3643 at drivers/scsi/scsi_lib.c:1032 scsi_alloc_sgtables+0xc7d/0xf70 drivers/scsi/scsi_lib.c:1032 Modules linked in: CPU: 2 PID: 3643 Comm: syz-executor397 Not tainted 5.17.0-rc3-syzkaller-00316-gb81b1829e7e3 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-204/01/2014 RIP: 0010:scsi_alloc_sgtables+0xc7d/0xf70 drivers/scsi/scsi_lib.c:1032 Code: e7 fc 31 ff 44 89 f6 e8 c1 4e e7 fc 45 85 f6 0f 84 1a f5 ff ff e8 93 4c e7 fc 83 c5 01 0f b7 ed e9 0f f5 ff ff e8 83 4c e7 fc <0f> 0b 41 bc 0a 00 00 00 e9 2b fb ff ff 41 bc 09 00 00 00 e9 20 fb RSP: 0018:ffffc90000d07558 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88801bfc96a0 RCX: 0000000000000000 RDX: ffff88801c876000 RSI: ffffffff849060bd RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff849055b9 R11: 0000000000000000 R12: ffff888012b8c000 R13: ffff88801bfc9580 R14: 0000000000000000 R15: ffff88801432c000 FS: 00007effdec8e700(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007effdec6d718 CR3: 00000000206d6000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: scsi_setup_scsi_cmnd drivers/scsi/scsi_lib.c:1219 [inline] scsi_prepare_cmd drivers/scsi/scsi_lib.c:1614 [inline] scsi_queue_rq+0x283e/0x3630 drivers/scsi/scsi_lib.c:1730 blk_mq_dispatch_rq_list+0x6ea/0x22e0 block/blk-mq.c:1851 __blk_mq_sched_dispatch_requests+0x20b/0x410 block/blk-mq-sched.c:299 blk_mq_sched_dispatch_requests+0xfb/0x180 block/blk-mq-sched.c:332 __blk_mq_run_hw_queue+0xf9/0x350 block/blk-mq.c:1968 __blk_mq_delay_run_hw_queue+0x5b6/0x6c0 block/blk-mq.c:2045 blk_mq_run_hw_queue+0x30f/0x480 block/blk-mq.c:2096 blk_mq_sched_insert_request+0x340/0x440 block/blk-mq-sched.c:451 blk_execute_rq+0xcc/0x340 block/blk-mq.c:1231 sg_io+0x67c/0x1210 drivers/scsi/scsi_ioctl.c:485 scsi_ioctl_sg_io drivers/scsi/scsi_ioctl.c:866 [inline] scsi_ioctl+0xa66/0x1560 drivers/scsi/scsi_ioctl.c:921 sd_ioctl+0x199/0x2a0 drivers/scsi/sd.c:1576 blkdev_ioctl+0x37a/0x800 block/ioctl.c:588 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7effdecdc5d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007effdec8e2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007effded664c0 RCX: 00007effdecdc5d9 RDX: 0000000020002300 RSI: 0000000000002285 RDI: 0000000000000004 RBP: 00007effded34034 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007effded34054 R14: 2f30656c69662f2e R15: 00007effded664c8 Reported-by: syzbot+d44b35ecfb807e5af0b5@syzkaller.appspotmail.com Fixes: 25636e282fe9 (block: fix SG_IO vector request data length handling) Signed-off-by: Jason Yan Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche --- drivers/scsi/scsi_ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c index a480c4d589f5..729e309e6034 100644 --- a/drivers/scsi/scsi_ioctl.c +++ b/drivers/scsi/scsi_ioctl.c @@ -450,7 +450,7 @@ static int sg_io(struct scsi_device *sdev, struct sg_io_hdr *hdr, fmode_t mode) goto out_put_request; ret = 0; - if (hdr->iovec_count) { + if (hdr->iovec_count && hdr->dxfer_len) { struct iov_iter i; struct iovec *iov = NULL;