From patchwork Mon May 27 14:22:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yue Haibing X-Patchwork-Id: 10963247 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BF4EC1390 for ; Mon, 27 May 2019 14:23:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AECBB28B86 for ; Mon, 27 May 2019 14:23:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2C4E28B83; Mon, 27 May 2019 14:23:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 37E3A28972 for ; Mon, 27 May 2019 14:23:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726207AbfE0OXX (ORCPT ); Mon, 27 May 2019 10:23:23 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:17167 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726115AbfE0OXX (ORCPT ); Mon, 27 May 2019 10:23:23 -0400 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 1E1FFFED7482FF4080F8; Mon, 27 May 2019 22:23:21 +0800 (CST) Received: from localhost (10.177.31.96) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.439.0; Mon, 27 May 2019 22:23:14 +0800 From: YueHaibing To: , , , , CC: , , YueHaibing Subject: [PATCH] scsi: scsi_dh_alua: Fix possible null-ptr-deref Date: Mon, 27 May 2019 22:22:09 +0800 Message-ID: <20190527142209.21768-1-yuehaibing@huawei.com> X-Mailer: git-send-email 2.10.2.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.177.31.96] X-CFilter-Loop: Reflected Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If alloc_workqueue fails in alua_init, it should return -ENOMEM, otherwise it will trigger null-ptr-deref while unloading module which calls destroy_workqueue dereference wq->lock like this: BUG: KASAN: null-ptr-deref in __lock_acquire+0x6b4/0x1ee0 Read of size 8 at addr 0000000000000080 by task syz-executor.0/7045 CPU: 0 PID: 7045 Comm: syz-executor.0 Tainted: G C 5.1.0+ #28 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 Call Trace: dump_stack+0xa9/0x10e __kasan_report+0x171/0x18d ? __lock_acquire+0x6b4/0x1ee0 kasan_report+0xe/0x20 __lock_acquire+0x6b4/0x1ee0 lock_acquire+0xb4/0x1b0 __mutex_lock+0xd8/0xb90 drain_workqueue+0x25/0x290 destroy_workqueue+0x1f/0x3f0 __x64_sys_delete_module+0x244/0x330 do_syscall_64+0x72/0x2a0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reported-by: Hulk Robot Fixes: 03197b61c5ec ("scsi_dh_alua: Use workqueue for RTPG") Signed-off-by: YueHaibing Reviewed-by: Bart Van Assche --- drivers/scsi/device_handler/scsi_dh_alua.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index d7ac498ba35a..2a9dcb8973b7 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -1174,10 +1174,8 @@ static int __init alua_init(void) int r; kaluad_wq = alloc_workqueue("kaluad", WQ_MEM_RECLAIM, 0); - if (!kaluad_wq) { - /* Temporary failure, bypass */ - return SCSI_DH_DEV_TEMP_BUSY; - } + if (!kaluad_wq) + return -ENOMEM; r = scsi_register_device_handler(&alua_dh); if (r != 0) {