From patchwork Fri Oct 28 03:33:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: shaozhengchao X-Patchwork-Id: 13023020 X-Patchwork-Delegate: kuba@kernel.org 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 84007ECAAA1 for ; Fri, 28 Oct 2022 03:26:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235872AbiJ1D02 (ORCPT ); Thu, 27 Oct 2022 23:26:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229683AbiJ1D00 (ORCPT ); Thu, 27 Oct 2022 23:26:26 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C97D6A51E; Thu, 27 Oct 2022 20:26:24 -0700 (PDT) Received: from dggpeml500026.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Mz7HN1KPKzHvVP; Fri, 28 Oct 2022 11:26:08 +0800 (CST) Received: from huawei.com (10.175.101.6) by dggpeml500026.china.huawei.com (7.185.36.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 28 Oct 2022 11:26:22 +0800 From: Zhengchao Shao To: , , , , , , , CC: , , , Subject: [PATCH net] can: af_can: fix NULL pointer dereference in can_rx_register() Date: Fri, 28 Oct 2022 11:33:42 +0800 Message-ID: <20221028033342.173528-1-shaozhengchao@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500026.china.huawei.com (7.185.36.106) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org It causes NULL pointer dereference when testing as following: (a) use syscall(__NR_socket, 0x10ul, 3ul, 0) to create netlink socket. (b) use syscall(__NR_sendmsg, ...) to create bond link device and vxcan link device, and bind vxcan device to bond device (can also use ifenslave command to bind vxcan device to bond device). (c) use syscall(__NR_socket, 0x1dul, 3ul, 1) to create CAN socket. (d) use syscall(__NR_bind, ...) to bind the bond device to CAN socket. The bond device invokes the can-raw protocol registration interface to receive CAN packets. However, ml_priv is not allocated to the dev, dev_rcv_lists is assigned to NULL in can_rx_register(). In this case, it will occur the NULL pointer dereference issue. The following is the stack information: BUG: kernel NULL pointer dereference, address: 0000000000000008 PGD 122a4067 P4D 122a4067 PUD 1223c067 PMD 0 Oops: 0000 [#1] PREEMPT SMP RIP: 0010:can_rx_register+0x12d/0x1e0 Call Trace: raw_enable_filters+0x8d/0x120 raw_enable_allfilters+0x3b/0x130 raw_bind+0x118/0x4f0 __sys_bind+0x163/0x1a0 __x64_sys_bind+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device") Signed-off-by: Zhengchao Shao Reviewed-by: Marc Kleine-Budde --- net/can/af_can.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/can/af_can.c b/net/can/af_can.c index 9503ab10f9b8..ef2697f3ebcb 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -450,7 +450,7 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, /* insert new receiver (dev,canid,mask) -> (func,data) */ - if (dev && dev->type != ARPHRD_CAN) + if (dev && (dev->type != ARPHRD_CAN || dev->ml_priv_type != ML_PRIV_CAN)) return -ENODEV; if (dev && !net_eq(net, dev_net(dev)))