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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E032EC04E53 for ; Wed, 15 May 2019 14:39:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD6892084E for ; Wed, 15 May 2019 14:39:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728267AbfEOOjz (ORCPT ); Wed, 15 May 2019 10:39:55 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:47382 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726452AbfEOOjy (ORCPT ); Wed, 15 May 2019 10:39:54 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id AF3D9B02FB4AF1FEF342; Wed, 15 May 2019 22:39:45 +0800 (CST) Received: from huawei.com (10.184.227.228) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.439.0; Wed, 15 May 2019 22:39:37 +0800 From: Wang Hai To: , , , CC: , , Subject: [PATCH] memstick: Fix error cleanup path of memstick_init Date: Wed, 15 May 2019 22:37:25 +0800 Message-ID: <20190515143725.18872-1-wanghai26@huawei.com> X-Mailer: git-send-email 2.10.2.windows.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.184.227.228] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If bus_register fails. On its error handling path, it has cleaned up what it has done. There is no need to call bus_unregister again. Otherwise, if bus_unregister is called, issues such as null-ptr-deref will arise. Syzkaller report this: kobject_add_internal failed for memstick (error: -12 parent: bus) BUG: KASAN: null-ptr-deref in sysfs_remove_file_ns+0x1b/0x40 fs/sysfs/file.c:467 Read of size 8 at addr 0000000000000078 by task syz-executor.0/4460 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xa9/0x10e lib/dump_stack.c:113 __kasan_report+0x171/0x18d mm/kasan/report.c:321 kasan_report+0xe/0x20 mm/kasan/common.c:614 sysfs_remove_file_ns+0x1b/0x40 fs/sysfs/file.c:467 sysfs_remove_file include/linux/sysfs.h:519 [inline] bus_remove_file+0x6c/0x90 drivers/base/bus.c:145 remove_probe_files drivers/base/bus.c:599 [inline] bus_unregister+0x6e/0x100 drivers/base/bus.c:916 ? 0xffffffffc1590000 memstick_init+0x7a/0x1000 [memstick] do_one_initcall+0xb9/0x3b5 init/main.c:914 do_init_module+0xe0/0x330 kernel/module.c:3468 load_module+0x38eb/0x4270 kernel/module.c:3819 __do_sys_finit_module+0x162/0x190 kernel/module.c:3909 do_syscall_64+0x72/0x2a0 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: baf8532a147d ("memstick: initial commit for Sony MemoryStick support") Reported-by: Hulk Robot Signed-off-by: Wang Hai --- drivers/memstick/core/memstick.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/memstick/core/memstick.c b/drivers/memstick/core/memstick.c index 1246d69ba187..b1564cacd19e 100644 --- a/drivers/memstick/core/memstick.c +++ b/drivers/memstick/core/memstick.c @@ -629,13 +629,18 @@ static int __init memstick_init(void) return -ENOMEM; rc = bus_register(&memstick_bus_type); - if (!rc) - rc = class_register(&memstick_host_class); + if (rc) + goto error_destroy_workqueue; - if (!rc) - return 0; + rc = class_register(&memstick_host_class); + if (rc) + goto error_bus_unregister; + + return 0; +error_bus_unregister: bus_unregister(&memstick_bus_type); +error_destroy_workqueue: destroy_workqueue(workqueue); return rc; -- 2.17.1