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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 0D61FC43215 for ; Tue, 3 Dec 2019 22:44:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1B5C2073C for ; Tue, 3 Dec 2019 22:44:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413049; bh=7MvPI7DYjNIA6rCIusYeQYGLvxmcdB79bxNyOSfjzEs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=l9j3iGXgQNckMe/rL+JNmH2tYObYAiUP2mKrI7LkBZQDAHiOrIAHDEKgj+ilZJOBp rspKHjMlwTccv3KUSGrZA0e4MBYKpfamWFrym75cM+Cpe8Z+cxAGCt/X+K9emybAxu J5qZWMUZgeXbJUyquAAtEM45uKcfIZDdaLrnpSuU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728914AbfLCWoI (ORCPT ); Tue, 3 Dec 2019 17:44:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:59838 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728897AbfLCWoG (ORCPT ); Tue, 3 Dec 2019 17:44:06 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2D0F920803; Tue, 3 Dec 2019 22:44:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413045; bh=7MvPI7DYjNIA6rCIusYeQYGLvxmcdB79bxNyOSfjzEs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vj4IEAsn13tpE/T8lRuQPu44asD13H2NTG40gVdyQmAgegTvbIVLUIvct/vEsuHrD mjASgCybhD/bndeMpiS1cV72qlpwhrg2n9Pwie06KDSuOAHdwdWRiYi68HPVpxO0Ym 6kugmbkpLNo3QDxgLwl3D3AqXbJi8GoUhvn1jH7w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yotam Gigi , Jiri Pirko , Jamal Hadi Salim , Simon Horman , Roopa Prabhu , Nikolay Aleksandrov , "David S. Miller" Subject: [PATCH 5.3 114/135] net: psample: fix skb_over_panic Date: Tue, 3 Dec 2019 23:35:54 +0100 Message-Id: <20191203213042.806588618@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203213005.828543156@linuxfoundation.org> References: <20191203213005.828543156@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nikolay Aleksandrov [ Upstream commit 7eb9d7675c08937cd11d32b0b40442d4d731c5ee ] We need to calculate the skb size correctly otherwise we risk triggering skb_over_panic[1]. The issue is that data_len is added to the skb in a nl attribute, but we don't account for its header size (nlattr 4 bytes) and alignment. We account for it when calculating the total size in the > PSAMPLE_MAX_PACKET_SIZE comparison correctly, but not when allocating after that. The fix is simple - use nla_total_size() for data_len when allocating. To reproduce: $ tc qdisc add dev eth1 clsact $ tc filter add dev eth1 egress matchall action sample rate 1 group 1 trunc 129 $ mausezahn eth1 -b bcast -a rand -c 1 -p 129 < skb_over_panic BUG(), tail is 4 bytes past skb->end > [1] Trace: [ 50.459526][ T3480] skbuff: skb_over_panic: text:(____ptrval____) len:196 put:136 head:(____ptrval____) data:(____ptrval____) tail:0xc4 end:0xc0 dev: [ 50.474339][ T3480] ------------[ cut here ]------------ [ 50.481132][ T3480] kernel BUG at net/core/skbuff.c:108! [ 50.486059][ T3480] invalid opcode: 0000 [#1] PREEMPT SMP [ 50.489463][ T3480] CPU: 3 PID: 3480 Comm: mausezahn Not tainted 5.4.0-rc7 #108 [ 50.492844][ T3480] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014 [ 50.496551][ T3480] RIP: 0010:skb_panic+0x79/0x7b [ 50.498261][ T3480] Code: bc 00 00 00 41 57 4c 89 e6 48 c7 c7 90 29 9a 83 4c 8b 8b c0 00 00 00 50 8b 83 b8 00 00 00 50 ff b3 c8 00 00 00 e8 ae ef c0 fe <0f> 0b e8 2f df c8 fe 48 8b 55 08 44 89 f6 4c 89 e7 48 c7 c1 a0 22 [ 50.504111][ T3480] RSP: 0018:ffffc90000447a10 EFLAGS: 00010282 [ 50.505835][ T3480] RAX: 0000000000000087 RBX: ffff888039317d00 RCX: 0000000000000000 [ 50.507900][ T3480] RDX: 0000000000000000 RSI: ffffffff812716e1 RDI: 00000000ffffffff [ 50.509820][ T3480] RBP: ffffc90000447a60 R08: 0000000000000001 R09: 0000000000000000 [ 50.511735][ T3480] R10: ffffffff81d4f940 R11: 0000000000000000 R12: ffffffff834a22b0 [ 50.513494][ T3480] R13: ffffffff82c10433 R14: 0000000000000088 R15: ffffffff838a8084 [ 50.515222][ T3480] FS: 00007f3536462700(0000) GS:ffff88803eac0000(0000) knlGS:0000000000000000 [ 50.517135][ T3480] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 50.518583][ T3480] CR2: 0000000000442008 CR3: 000000003b222000 CR4: 00000000000006e0 [ 50.520723][ T3480] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 50.522709][ T3480] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 50.524450][ T3480] Call Trace: [ 50.525214][ T3480] skb_put.cold+0x1b/0x1b [ 50.526171][ T3480] psample_sample_packet+0x1d3/0x340 [ 50.527307][ T3480] tcf_sample_act+0x178/0x250 [ 50.528339][ T3480] tcf_action_exec+0xb1/0x190 [ 50.529354][ T3480] mall_classify+0x67/0x90 [ 50.530332][ T3480] tcf_classify+0x72/0x160 [ 50.531286][ T3480] __dev_queue_xmit+0x3db/0xd50 [ 50.532327][ T3480] dev_queue_xmit+0x18/0x20 [ 50.533299][ T3480] packet_sendmsg+0xee7/0x2090 [ 50.534331][ T3480] sock_sendmsg+0x54/0x70 [ 50.535271][ T3480] __sys_sendto+0x148/0x1f0 [ 50.536252][ T3480] ? tomoyo_file_ioctl+0x23/0x30 [ 50.537334][ T3480] ? ksys_ioctl+0x5e/0xb0 [ 50.540068][ T3480] __x64_sys_sendto+0x2a/0x30 [ 50.542810][ T3480] do_syscall_64+0x73/0x1f0 [ 50.545383][ T3480] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.548477][ T3480] RIP: 0033:0x7f35357d6fb3 [ 50.551020][ T3480] Code: 48 8b 0d 18 90 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 d3 20 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 eb f6 ff ff 48 89 04 24 [ 50.558547][ T3480] RSP: 002b:00007ffe0c7212c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 50.561870][ T3480] RAX: ffffffffffffffda RBX: 0000000001dac010 RCX: 00007f35357d6fb3 [ 50.565142][ T3480] RDX: 0000000000000082 RSI: 0000000001dac2a2 RDI: 0000000000000003 [ 50.568469][ T3480] RBP: 00007ffe0c7212f0 R08: 00007ffe0c7212d0 R09: 0000000000000014 [ 50.571731][ T3480] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000082 [ 50.574961][ T3480] R13: 0000000001dac2a2 R14: 0000000000000001 R15: 0000000000000003 [ 50.578170][ T3480] Modules linked in: sch_ingress virtio_net [ 50.580976][ T3480] ---[ end trace 61a515626a595af6 ]--- CC: Yotam Gigi CC: Jiri Pirko CC: Jamal Hadi Salim CC: Simon Horman CC: Roopa Prabhu Fixes: 6ae0a6286171 ("net: Introduce psample, a new genetlink channel for packet sampling") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/psample/psample.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/psample/psample.c +++ b/net/psample/psample.c @@ -221,7 +221,7 @@ void psample_sample_packet(struct psampl data_len = PSAMPLE_MAX_PACKET_SIZE - meta_len - NLA_HDRLEN - NLA_ALIGNTO; - nl_skb = genlmsg_new(meta_len + data_len, GFP_ATOMIC); + nl_skb = genlmsg_new(meta_len + nla_total_size(data_len), GFP_ATOMIC); if (unlikely(!nl_skb)) return;