From patchwork Sat Mar 9 03:43:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yue Haibing X-Patchwork-Id: 1053791 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44GVc52sKcz9s71 for ; Sat, 9 Mar 2019 14:44:37 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726641AbfCIDoP (ORCPT ); Fri, 8 Mar 2019 22:44:15 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:42476 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726512AbfCIDoP (ORCPT ); Fri, 8 Mar 2019 22:44:15 -0500 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id B1F5D2E825719300B473; Sat, 9 Mar 2019 11:44:12 +0800 (CST) Received: from localhost (10.177.31.96) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.408.0; Sat, 9 Mar 2019 11:44:05 +0800 From: Yue Haibing To: , , CC: , , , YueHaibing Subject: [PATCH] can: af_can: Fix possible NULL pointer dereference in can_exit Date: Sat, 9 Mar 2019 11:43:31 +0800 Message-ID: <20190309034331.17944-1-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: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: YueHaibing Syzkaller report this: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 9400 Comm: syz-executor.0 Tainted: G C 5.0.0-rc8+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:__list_del include/linux/list.h:105 [inline] RIP: 0010:__list_del_entry include/linux/list.h:120 [inline] RIP: 0010:list_del include/linux/list.h:125 [inline] RIP: 0010:__unregister_pernet_operations net/core/net_namespace.c:1075 [inline] RIP: 0010:unregister_pernet_operations+0x124/0x540 net/core/net_namespace.c:1137 Code: 89 c1 48 c1 e9 03 80 3c 11 00 0f 85 38 03 00 00 48 8d 7d 08 48 ba 00 00 00 00 00 fc ff df 4d 8b 7c 24 08 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 02 03 00 00 48 8d 9c 24 b8 00 00 00 48 ba 00 00 RSP: 0018:ffff8881b871fbb0 EFLAGS: 00010a06 RAX: ffffffffc198c4c8 RBX: dffffc0000000000 RCX: 1bd5a00000000021 RDX: dffffc0000000000 RSI: ffffc900014c4000 RDI: dead000000000108 RBP: dead000000000100 R08: 0000000000000001 R09: 0000000000000000 R10: ffff8881b871fb30 R11: 0000000000000000 R12: ffffffffc198c4c0 R13: ffff8881b871fbe8 R14: 1ffff110370e3f79 R15: dead000000000200 FS: 00007f029df32700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc85454218 CR3: 00000001e0ff4004 CR4: 00000000007606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: unregister_pernet_subsys+0x1d/0x30 net/core/net_namespace.c:1184 can_exit+0x3f/0x56 [can] __do_sys_delete_module kernel/module.c:1018 [inline] __se_sys_delete_module kernel/module.c:961 [inline] __x64_sys_delete_module+0x3dc/0x5e0 kernel/module.c:961 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x462e99 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f029df31c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f029df326bc R13: 00000000004bcca9 R14: 00000000006f6b48 R15: 00000000ffffffff register_pernet_subsys may fails in can_init,then can_exit calls unregister_pernet_subsys when unloading, it can trigger a NULL pointer dereference while doing list_del.This patch fix error cleanup path of can_init to avoid this. Reported-by: Hulk Robot Signed-off-by: YueHaibing --- net/can/af_can.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/net/can/af_can.c b/net/can/af_can.c index 1684ba5..5d75685 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -958,6 +958,8 @@ static struct pernet_operations can_pernet_ops __read_mostly = { static __init int can_init(void) { + int rc; + /* check for correct padding to be able to use the structs similarly */ BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) != offsetof(struct canfd_frame, len) || @@ -971,15 +973,31 @@ static __init int can_init(void) if (!rcv_cache) return -ENOMEM; - register_pernet_subsys(&can_pernet_ops); + rc = register_pernet_subsys(&can_pernet_ops); + if (rc) + goto free_cache; /* protocol register */ - sock_register(&can_family_ops); - register_netdevice_notifier(&can_netdev_notifier); + rc = sock_register(&can_family_ops); + if (rc) + goto unregister_pernet; + + rc = register_netdevice_notifier(&can_netdev_notifier); + if (rc) + goto sock_unregister; + dev_add_pack(&can_packet); dev_add_pack(&canfd_packet); return 0; + +sock_unregister: + sock_unregister(PF_CAN); +unregister_pernet: + unregister_pernet_subsys(&can_pernet_ops); +free_cache: + kmem_cache_destroy(rcv_cache); + return rc; } static __exit void can_exit(void)