From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 300444C6A for ; Mon, 14 Nov 2022 13:02:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6FE4C433D6; Mon, 14 Nov 2022 13:02:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1668430979; bh=BQU4oVSPWwh62WANtRuL5npNTTJ42rDyjueUFGgDjsw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VXcSRHV6AeIBXo1/LqApaffwE4G/jFqiDH4krBWvb5h+/h6BgYMUxOsqNev+51LTm 0zeWCvYw890Z2+xzetDfMceY29Els692XO6C148RryS6cewvz2nMz4o9p6PLzuIFUf AX7L48462q0Rt1+qxFQ94SSFJiq9bpAfNhNOAAnA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhengchao Shao , Marc Kleine-Budde , Sasha Levin Subject: [PATCH 6.0 056/190] can: af_can: fix NULL pointer dereference in can_rx_register() Date: Mon, 14 Nov 2022 13:44:40 +0100 Message-Id: <20221114124501.211374255@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221114124458.806324402@linuxfoundation.org> References: <20221114124458.806324402@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Zhengchao Shao [ Upstream commit 8aa59e355949442c408408c2d836e561794c40a1 ] 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 Link: https://lore.kernel.org/all/20221028085650.170470-1-shaozhengchao@huawei.com Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- 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 1fb49d51b25d..e48ccf7cf200 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -451,7 +451,7 @@ 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 || !can_get_ml_priv(dev))) return -ENODEV; if (dev && !net_eq(net, dev_net(dev))) -- 2.35.1