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[209.132.180.67]) by mx.google.com with ESMTP id d1-v6si16640862pgo.2.2018.05.24.03.37.08; Thu, 24 May 2018 03:37:23 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=PUbEqhDa; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031076AbeEXKgU (ORCPT + 99 others); Thu, 24 May 2018 06:36:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:41874 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968316AbeEXKAJ (ORCPT ); Thu, 24 May 2018 06:00:09 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) (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 A620620890; Thu, 24 May 2018 10:00:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1527156008; bh=6E1bZ7a0AMYYIPhbqB8kTaVpk0wJwfBrIKnfKiY8lYI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PUbEqhDaffX3iqhQmG24qzsniI4nO5BkAvFZWfxnssmov+FxMk8gOlFlLuXXUJVeq fJPCs9n0acJlB3EbWfESAxnCTiJFoNmsXPuurRSk6b7C8JTPO3YwLcb4I8uzep7T36 UbN9wSI9xbSqXGC4Czgw37tDEQg5Iay8JQn7V1HI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Petr Machata , William Tu , "David S. Miller" Subject: [PATCH 4.16 023/161] net: ip6_gre: Fix headroom request in ip6erspan_tunnel_xmit() Date: Thu, 24 May 2018 11:37:28 +0200 Message-Id: <20180524093021.141910303@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180524093018.331893860@linuxfoundation.org> References: <20180524093018.331893860@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Petr Machata [ Upstream commit 5691484df961aff897d824bcc26cd1a2aa036b5b ] dev->needed_headroom is not primed until ip6_tnl_xmit(), so it starts out zero. Thus the call to skb_cow_head() fails to actually make sure there's enough headroom to push the ERSPAN headers to. That can lead to the panic cited below. (Reproducer below that). Fix by requesting either needed_headroom if already primed, or just the bare minimum needed for the header otherwise. [ 190.703567] kernel BUG at net/core/skbuff.c:104! [ 190.708384] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI [ 190.714007] Modules linked in: act_mirred cls_matchall ip6_gre ip6_tunnel tunnel6 gre sch_ingress vrf veth x86_pkg_temp_thermal mlx_platform nfsd e1000e leds_mlxcpld [ 190.728975] CPU: 1 PID: 959 Comm: kworker/1:2 Not tainted 4.17.0-rc4-net_master-custom-139 #10 [ 190.737647] Hardware name: Mellanox Technologies Ltd. "MSN2410-CB2F"/"SA000874", BIOS 4.6.5 03/08/2016 [ 190.747006] Workqueue: ipv6_addrconf addrconf_dad_work [ 190.752222] RIP: 0010:skb_panic+0xc3/0x100 [ 190.756358] RSP: 0018:ffff8801d54072f0 EFLAGS: 00010282 [ 190.761629] RAX: 0000000000000085 RBX: ffff8801c1a8ecc0 RCX: 0000000000000000 [ 190.768830] RDX: 0000000000000085 RSI: dffffc0000000000 RDI: ffffed003aa80e54 [ 190.776025] RBP: ffff8801bd1ec5a0 R08: ffffed003aabce19 R09: ffffed003aabce19 [ 190.783226] R10: 0000000000000001 R11: ffffed003aabce18 R12: ffff8801bf695dbe [ 190.790418] R13: 0000000000000084 R14: 00000000000006c0 R15: ffff8801bf695dc8 [ 190.797621] FS: 0000000000000000(0000) GS:ffff8801d5400000(0000) knlGS:0000000000000000 [ 190.805786] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 190.811582] CR2: 000055fa929aced0 CR3: 0000000003228004 CR4: 00000000001606e0 [ 190.818790] Call Trace: [ 190.821264] [ 190.823314] ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre] [ 190.828940] ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre] [ 190.834562] skb_push+0x78/0x90 [ 190.837749] ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre] [ 190.843219] ? ip6gre_tunnel_ioctl+0xd90/0xd90 [ip6_gre] [ 190.848577] ? debug_check_no_locks_freed+0x210/0x210 [ 190.853679] ? debug_check_no_locks_freed+0x210/0x210 [ 190.858783] ? print_irqtrace_events+0x120/0x120 [ 190.863451] ? sched_clock_cpu+0x18/0x210 [ 190.867496] ? cyc2ns_read_end+0x10/0x10 [ 190.871474] ? skb_network_protocol+0x76/0x200 [ 190.875977] dev_hard_start_xmit+0x137/0x770 [ 190.880317] ? do_raw_spin_trylock+0x6d/0xa0 [ 190.884624] sch_direct_xmit+0x2ef/0x5d0 [ 190.888589] ? pfifo_fast_dequeue+0x3fa/0x670 [ 190.892994] ? pfifo_fast_change_tx_queue_len+0x810/0x810 [ 190.898455] ? __lock_is_held+0xa0/0x160 [ 190.902422] __qdisc_run+0x39e/0xfc0 [ 190.906041] ? _raw_spin_unlock+0x29/0x40 [ 190.910090] ? pfifo_fast_enqueue+0x24b/0x3e0 [ 190.914501] ? sch_direct_xmit+0x5d0/0x5d0 [ 190.918658] ? pfifo_fast_dequeue+0x670/0x670 [ 190.923047] ? __dev_queue_xmit+0x172/0x1770 [ 190.927365] ? preempt_count_sub+0xf/0xd0 [ 190.931421] __dev_queue_xmit+0x410/0x1770 [ 190.935553] ? ___slab_alloc+0x605/0x930 [ 190.939524] ? print_irqtrace_events+0x120/0x120 [ 190.944186] ? memcpy+0x34/0x50 [ 190.947364] ? netdev_pick_tx+0x1c0/0x1c0 [ 190.951428] ? __skb_clone+0x2fd/0x3d0 [ 190.955218] ? __copy_skb_header+0x270/0x270 [ 190.959537] ? rcu_read_lock_sched_held+0x93/0xa0 [ 190.964282] ? kmem_cache_alloc+0x344/0x4d0 [ 190.968520] ? cyc2ns_read_end+0x10/0x10 [ 190.972495] ? skb_clone+0x123/0x230 [ 190.976112] ? skb_split+0x820/0x820 [ 190.979747] ? tcf_mirred+0x554/0x930 [act_mirred] [ 190.984582] tcf_mirred+0x554/0x930 [act_mirred] [ 190.989252] ? tcf_mirred_act_wants_ingress.part.2+0x10/0x10 [act_mirred] [ 190.996109] ? __lock_acquire+0x706/0x26e0 [ 191.000239] ? sched_clock_cpu+0x18/0x210 [ 191.004294] tcf_action_exec+0xcf/0x2a0 [ 191.008179] tcf_classify+0xfa/0x340 [ 191.011794] __netif_receive_skb_core+0x8e1/0x1c60 [ 191.016630] ? debug_check_no_locks_freed+0x210/0x210 [ 191.021732] ? nf_ingress+0x500/0x500 [ 191.025458] ? process_backlog+0x347/0x4b0 [ 191.029619] ? print_irqtrace_events+0x120/0x120 [ 191.034302] ? lock_acquire+0xd8/0x320 [ 191.038089] ? process_backlog+0x1b6/0x4b0 [ 191.042246] ? process_backlog+0xc2/0x4b0 [ 191.046303] process_backlog+0xc2/0x4b0 [ 191.050189] net_rx_action+0x5cc/0x980 [ 191.053991] ? napi_complete_done+0x2c0/0x2c0 [ 191.058386] ? mark_lock+0x13d/0xb40 [ 191.062001] ? clockevents_program_event+0x6b/0x1d0 [ 191.066922] ? print_irqtrace_events+0x120/0x120 [ 191.071593] ? __lock_is_held+0xa0/0x160 [ 191.075566] __do_softirq+0x1d4/0x9d2 [ 191.079282] ? ip6_finish_output2+0x524/0x1460 [ 191.083771] do_softirq_own_stack+0x2a/0x40 [ 191.087994] [ 191.090130] do_softirq.part.13+0x38/0x40 [ 191.094178] __local_bh_enable_ip+0x135/0x190 [ 191.098591] ip6_finish_output2+0x54d/0x1460 [ 191.102916] ? ip6_forward_finish+0x2f0/0x2f0 [ 191.107314] ? ip6_mtu+0x3c/0x2c0 [ 191.110674] ? ip6_finish_output+0x2f8/0x650 [ 191.114992] ? ip6_output+0x12a/0x500 [ 191.118696] ip6_output+0x12a/0x500 [ 191.122223] ? ip6_route_dev_notify+0x5b0/0x5b0 [ 191.126807] ? ip6_finish_output+0x650/0x650 [ 191.131120] ? ip6_fragment+0x1a60/0x1a60 [ 191.135182] ? icmp6_dst_alloc+0x26e/0x470 [ 191.139317] mld_sendpack+0x672/0x830 [ 191.143021] ? igmp6_mcf_seq_next+0x2f0/0x2f0 [ 191.147429] ? __local_bh_enable_ip+0x77/0x190 [ 191.151913] ipv6_mc_dad_complete+0x47/0x90 [ 191.156144] addrconf_dad_completed+0x561/0x720 [ 191.160731] ? addrconf_rs_timer+0x3a0/0x3a0 [ 191.165036] ? mark_held_locks+0xc9/0x140 [ 191.169095] ? __local_bh_enable_ip+0x77/0x190 [ 191.173570] ? addrconf_dad_work+0x50d/0xa20 [ 191.177886] ? addrconf_dad_work+0x529/0xa20 [ 191.182194] addrconf_dad_work+0x529/0xa20 [ 191.186342] ? addrconf_dad_completed+0x720/0x720 [ 191.191088] ? __lock_is_held+0xa0/0x160 [ 191.195059] ? process_one_work+0x45d/0xe20 [ 191.199302] ? process_one_work+0x51e/0xe20 [ 191.203531] ? rcu_read_lock_sched_held+0x93/0xa0 [ 191.208279] process_one_work+0x51e/0xe20 [ 191.212340] ? pwq_dec_nr_in_flight+0x200/0x200 [ 191.216912] ? get_lock_stats+0x4b/0xf0 [ 191.220788] ? preempt_count_sub+0xf/0xd0 [ 191.224844] ? worker_thread+0x219/0x860 [ 191.228823] ? do_raw_spin_trylock+0x6d/0xa0 [ 191.233142] worker_thread+0xeb/0x860 [ 191.236848] ? process_one_work+0xe20/0xe20 [ 191.241095] kthread+0x206/0x300 [ 191.244352] ? process_one_work+0xe20/0xe20 [ 191.248587] ? kthread_stop+0x570/0x570 [ 191.252459] ret_from_fork+0x3a/0x50 [ 191.256082] Code: 14 3e ff 8b 4b 78 55 4d 89 f9 41 56 41 55 48 c7 c7 a0 cf db 82 41 54 44 8b 44 24 2c 48 8b 54 24 30 48 8b 74 24 20 e8 16 94 13 ff <0f> 0b 48 c7 c7 60 8e 1f 85 48 83 c4 20 e8 55 ef a6 ff 89 74 24 [ 191.275327] RIP: skb_panic+0xc3/0x100 RSP: ffff8801d54072f0 [ 191.281024] ---[ end trace 7ea51094e099e006 ]--- [ 191.285724] Kernel panic - not syncing: Fatal exception in interrupt [ 191.292168] Kernel Offset: disabled [ 191.295697] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Reproducer: ip link add h1 type veth peer name swp1 ip link add h3 type veth peer name swp3 ip link set dev h1 up ip address add 192.0.2.1/28 dev h1 ip link add dev vh3 type vrf table 20 ip link set dev h3 master vh3 ip link set dev vh3 up ip link set dev h3 up ip link set dev swp3 up ip address add dev swp3 2001:db8:2::1/64 ip link set dev swp1 up tc qdisc add dev swp1 clsact ip link add name gt6 type ip6erspan \ local 2001:db8:2::1 remote 2001:db8:2::2 oseq okey 123 ip link set dev gt6 up sleep 1 tc filter add dev swp1 ingress pref 1000 matchall skip_hw \ action mirred egress mirror dev gt6 ping -I h1 192.0.2.2 Fixes: e41c7c68ea77 ("ip6erspan: make sure enough headroom at xmit.") Signed-off-by: Petr Machata Acked-by: William Tu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_gre.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -908,7 +908,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit truncate = true; } - if (skb_cow_head(skb, dev->needed_headroom)) + if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen)) goto tx_err; t->parms.o_flags &= ~TUNNEL_KEY;