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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 549CAC433E9 for ; Mon, 11 Jan 2021 13:15:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CDAB2255F for ; Mon, 11 Jan 2021 13:15:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731656AbhAKNPJ (ORCPT ); Mon, 11 Jan 2021 08:15:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:32804 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732168AbhAKNOp (ORCPT ); Mon, 11 Jan 2021 08:14:45 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id DC107223E8; Mon, 11 Jan 2021 13:14:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610370869; bh=122yfl5uZB9gySMkgOc2/Kw3crOf15oWocWCe6J+HFU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0QEqjRGNlmT00/7p5XYo2Zg4R7+AqMK7yLpoFqxxFJDizFxAti40j+wpgNXlmLE8Y iSR5uf9a4621WBG6L+wGVxZo0b9n5HkwwPRyvPY+ShYJy1WXtiQf5wKZZF5wYF612j nkEADKQbI8Davv0gTgkfxlwhsz6uE49vgU0sWO3Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guillaume Nault , Taehee Yoo , Jakub Kicinski Subject: [PATCH 5.10 040/145] bareudp: Fix use of incorrect min_headroom size Date: Mon, 11 Jan 2021 14:01:04 +0100 Message-Id: <20210111130050.447867631@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111130048.499958175@linuxfoundation.org> References: <20210111130048.499958175@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Taehee Yoo [ Upstream commit 10ad3e998fa0c25315f27cf3002ff8b02dc31c38 ] In the bareudp6_xmit_skb(), it calculates min_headroom. At that point, it uses struct iphdr, but it's not correct. So panic could occur. The struct ipv6hdr should be used. Test commands: ip netns add A ip netns add B ip link add veth0 netns A type veth peer name veth1 netns B ip netns exec A ip link set veth0 up ip netns exec A ip a a 2001:db8:0::1/64 dev veth0 ip netns exec B ip link set veth1 up ip netns exec B ip a a 2001:db8:0::2/64 dev veth1 for i in {10..1} do let A=$i-1 ip netns exec A ip link add bareudp$i type bareudp dstport $i \ ethertype 0x86dd ip netns exec A ip link set bareudp$i up ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev bareudp$i ip netns exec A ip -6 r a 2001:db8:$i::2 encap ip6 src \ 2001:db8:$A::1 dst 2001:db8:$A::2 via 2001:db8:$i::2 \ dev bareudp$i ip netns exec B ip link add bareudp$i type bareudp dstport $i \ ethertype 0x86dd ip netns exec B ip link set bareudp$i up ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev bareudp$i ip netns exec B ip -6 r a 2001:db8:$i::1 encap ip6 src \ 2001:db8:$A::2 dst 2001:db8:$A::1 via 2001:db8:$i::1 \ dev bareudp$i done ip netns exec A ping 2001:db8:7::2 Splat looks like: [ 66.436679][ C2] skbuff: skb_under_panic: text:ffffffff928614c8 len:454 put:14 head:ffff88810abb4000 data:ffff88810abb3ffa tail:0x1c0 end:0x3ec0 dev:veth0 [ 66.441626][ C2] ------------[ cut here ]------------ [ 66.443458][ C2] kernel BUG at net/core/skbuff.c:109! [ 66.445313][ C2] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 66.447606][ C2] CPU: 2 PID: 913 Comm: ping Not tainted 5.10.0+ #819 [ 66.450251][ C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 66.453713][ C2] RIP: 0010:skb_panic+0x15d/0x15f [ 66.455345][ C2] Code: 98 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 60 8b 78 93 41 57 41 56 41 55 48 8b 54 24 20 48 8b 74 24 28 e8 b5 40 f9 ff <0f> 0b 48 8b 6c 24 20 89 34 24 e8 08 c9 98 fe 8b 34 24 48 c7 c1 80 [ 66.462314][ C2] RSP: 0018:ffff888119209648 EFLAGS: 00010286 [ 66.464281][ C2] RAX: 0000000000000089 RBX: ffff888003159000 RCX: 0000000000000000 [ 66.467216][ C2] RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed10232412c0 [ 66.469768][ C2] RBP: ffff88810a53d440 R08: ffffed102328018d R09: ffffed102328018d [ 66.472297][ C2] R10: ffff888119400c67 R11: ffffed102328018c R12: 000000000000000e [ 66.474833][ C2] R13: ffff88810abb3ffa R14: 00000000000001c0 R15: 0000000000003ec0 [ 66.477361][ C2] FS: 00007f37c0c72f00(0000) GS:ffff888119200000(0000) knlGS:0000000000000000 [ 66.480214][ C2] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 66.482296][ C2] CR2: 000055a058808570 CR3: 000000011039e002 CR4: 00000000003706e0 [ 66.484811][ C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 66.487793][ C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 66.490424][ C2] Call Trace: [ 66.491469][ C2] [ 66.492374][ C2] ? eth_header+0x28/0x190 [ 66.494054][ C2] ? eth_header+0x28/0x190 [ 66.495401][ C2] skb_push.cold.99+0x22/0x22 [ 66.496700][ C2] eth_header+0x28/0x190 [ 66.497867][ C2] neigh_resolve_output+0x3de/0x720 [ 66.499615][ C2] ? __neigh_update+0x7e8/0x20a0 [ 66.501176][ C2] __neigh_update+0x8bd/0x20a0 [ 66.502749][ C2] ndisc_update+0x34/0xc0 [ 66.504010][ C2] ndisc_recv_na+0x8da/0xb80 [ 66.505041][ C2] ? pndisc_redo+0x20/0x20 [ 66.505888][ C2] ? rcu_read_lock_sched_held+0xc0/0xc0 [ 66.506965][ C2] ndisc_rcv+0x3a0/0x470 [ 66.507797][ C2] icmpv6_rcv+0xad9/0x1b00 [ 66.508645][ C2] ip6_protocol_deliver_rcu+0xcd6/0x1560 [ 66.509719][ C2] ip6_input_finish+0x5b/0xf0 [ 66.510615][ C2] ip6_input+0xcd/0x2d0 [ 66.511406][ C2] ? ip6_input_finish+0xf0/0xf0 [ 66.512327][ C2] ? rcu_read_lock_held+0x91/0xa0 [ 66.513279][ C2] ? ip6_protocol_deliver_rcu+0x1560/0x1560 [ 66.514414][ C2] ipv6_rcv+0xe8/0x300 [ ... ] Acked-by: Guillaume Nault Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.") Signed-off-by: Taehee Yoo Link: https://lore.kernel.org/r/20201228152146.24270-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/bareudp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/bareudp.c +++ b/drivers/net/bareudp.c @@ -380,7 +380,7 @@ static int bareudp6_xmit_skb(struct sk_b goto free_dst; min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len + - BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr); + BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr); err = skb_cow_head(skb, min_headroom); if (unlikely(err))