From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: kernel panic when using netns+bridges+tc(netem) Date: Thu, 06 May 2010 08:40:02 +0200 Message-ID: <1273128002.2304.4.camel@edumazet-laptop> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev , Mathieu Lacage , David Miller To: =?ISO-8859-1?Q?Mart=EDn?= Ferrari Return-path: Received: from mail-bw0-f219.google.com ([209.85.218.219]:38698 "EHLO mail-bw0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165Ab0EFGkJ (ORCPT ); Thu, 6 May 2010 02:40:09 -0400 Received: by bwz19 with SMTP id 19so295557bwz.21 for ; Wed, 05 May 2010 23:40:07 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Le jeudi 06 mai 2010 =C3=A0 03:01 +0200, Mart=C3=ADn Ferrari a =C3=A9cr= it : > Hi there, >=20 > While working on my project that uses netns, I found another bug. Thi= s > one causes a "Kernel panic - not syncing: Fatal exception in > interrupt", and I can reproduce it in 2.6.33 and 2.6.34-rc5, but not > in 2.6.32. It dies during a call to __free_skb. > I tested this on my x86_64 laptop (2 cores) and on qemu. In qemu it > was not triggered until I asked it to emulate 2 cpus instead of one, > so it is probably a SMP-only issue. >=20 > Scenario: >=20 > I set up a number of network namespaces, each with two veths to netns > 1. In the main namespace I take those veths and bridge them in pairs, > to configure a linear topology; also I configure the netem qdisc to > simulate link delay. >=20 > Once the network is set up, I run a client/server program to send UDP > packets from one end of the topology to the other. After a few second= s > of sending packets (not really deterministic) it panics. >=20 > Note that I didn't experience this problem when using only 2 > namespaces (so, no routing) >=20 > below the dumps. These all come from the qemu, as I couldn't use > netconsole in the network at work, but I checked and the backtraces > were essentially the same >=20 > First, two panics with 2.6.34, each one with a slightly different bac= ktrace >=20 > [ 65.272131] ------------[ cut here ]------------ > [ 65.272135] kernel BUG at mm/slub.c:2846! > [ 65.272135] invalid opcode: 0000 [#1] SMP > [ 65.272135] last sysfs file: /sys/devices/virtual/net/lo/operstate > [ 65.272135] CPU 1 > [ 65.272135] Modules linked in: sch_netem veth bridge stp netconsol= e > configfs loop parport_pc parport evdev tpm_tis tpm snd_pcm tpm_bios > snd_timer snd soundcore snd_page_alloc pcspkr psmouse serio_raw > i2c_piix4 button i2c_core processor ext3 jbd mbcache ide_cd_mod cdrom > ide_gd_mod ata_generic ata_piix libata 8139too scsi_mod floppy piix > 8139cp mii ide_core thermal thermal_sys [last unloaded: configfs] > [ 65.272135] > [ 65.272135] Pid: 1518, comm: udp-perf Not tainted 2.6.34-rc5 #1 / > [ 65.272135] RIP: 0010:[] [] > kfree+0x55/0xc6 > [ 65.272135] RSP: 0018:ffff880001a23d90 EFLAGS: 00010246 > [ 65.272135] RAX: 0100000000000000 RBX: ffff88007d6bc600 RCX: 00000= 00000012850 > [ 65.272135] RDX: ffff88007d6bc600 RSI: 000000000000000e RDI: ffffe= a0001b6f610 > [ 65.272135] RBP: ffff88007d6ae200 R08: ffff88007d6bc600 R09: fffff= fffa0280690 > [ 65.272135] R10: 0000000000000002 R11: ffff88007d6bc500 R12: fffff= fff8123a77f > [ 65.272135] R13: 000000000000002b R14: ffff88007d39b600 R15: ffff8= 8007d6bc600 > [ 65.272135] FS: 00007f637c9dd6f0(0000) GS:ffff880001a20000(0000) > knlGS:0000000000000000 > [ 65.272135] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 65.272135] CR2: 00000000009deaa0 CR3: 000000007d82d000 CR4: 00000= 000000006e0 > [ 65.272135] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000= 00000000000 > [ 65.272135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000= 00000000400 > [ 65.272135] Process udp-perf (pid: 1518, threadinfo > ffff88007d92a000, task ffff88007e7ff810) > [ 65.272135] Stack: > [ 65.272135] ffff88007d6bc600 ffff88007d6bc600 0000000000000246 > ffffffff8123a77f > [ 65.272135] <0> ffff880001a32860 ffffffff81241e01 ffffe8ffff623280 > ffffe8ffff83ffc0 > [ 65.272135] <0> ffff88007d6bc600 ffffffffa028057d 000000027d4c06c8 > ffff88007d4c0600 > [ 65.272135] Call Trace: > [ 65.272135] > [ 65.272135] [] ? __kfree_skb+0x11/0x7d > [ 65.272135] [] ? netif_rx+0xe2/0xee > [ 65.272135] [] ? veth_xmit+0x6e/0xad [veth] > [ 65.272135] [] ? dev_hard_start_xmit+0x221/0x30= 1 > [ 65.272135] [] ? sch_direct_xmit+0x5b/0x15d > [ 65.272135] [] ? __qdisc_run+0xb9/0xd8 > [ 65.272135] [] ? net_tx_action+0xd6/0x149 > [ 65.272135] [] ? __do_softirq+0xdd/0x19f > [ 65.272135] [] ? lapic_next_event+0x18/0x1d > [ 65.272135] [] ? call_softirq+0x1c/0x30 > [ 65.272135] [] ? do_softirq+0x3f/0x79 > [ 65.272135] [] ? irq_exit+0x36/0x76 > [ 65.272135] [] ? smp_apic_timer_interrupt+0x86/= 0x94 > [ 65.272135] [] ? apic_timer_interrupt+0x13/0x20 > [ 65.272135] > [ 65.272135] [] ? cap_sk_getsecid+0x0/0x1 > [ 65.272135] [] ? __xfrm_lookup+0x2/0xb04 > [ 65.272135] [] ? ip_route_output_flow+0x77/0x1c= c > [ 65.272135] [] ? udp_sendmsg+0x32d/0x5f3 > [ 65.272135] [] ? irq_entries_start+0x3c0/0x400 > [ 65.272135] [] ? inet_sendmsg+0x53/0x58 > [ 65.272135] [] ? sock_sendmsg+0x83/0x9b > [ 65.272135] [] ? pick_next_task_fair+0xca/0xd6 > [ 65.272135] [] ? schedule+0x52b/0x593 > [ 65.272135] [] ? apic_timer_interrupt+0xe/0x20 > [ 65.272135] [] ? apic_timer_interrupt+0xe/0x20 > [ 65.272135] [] ? _copy_from_user+0x1b/0x30 > [ 65.272135] [] ? __switch_to+0x1b5/0x2a6 > [ 65.272135] [] ? copy_from_user+0x13/0x25 > [ 65.272135] [] ? sys_sendto+0xd7/0x117 > [ 65.272135] [] ? finish_task_switch+0x34/0xa1 > [ 65.272135] [] ? schedule+0x52b/0x593 > [ 65.272135] [] ? apic_timer_interrupt+0xe/0x20 > [ 65.272135] [] ? system_call_fastpath+0x16/0x1b > [ 65.272135] Code: 83 c3 08 48 83 3b 00 eb ec 48 83 fd 10 0f 86 84 > 00 00 00 48 89 ef e8 f4 e2 ff ff 48 89 c7 48 8b 00 84 c0 78 13 66 a9 > 00 c0 75 04 <0f> 0b eb fe 5b 5d 41 5c e9 fb 57 fd ff 48 8b 4c 24 18 4= c > 8b 47 > [ 65.272135] RIP [] kfree+0x55/0xc6 > [ 65.272135] RSP > [ 65.385803] ---[ end trace 42d2fb5b94980ab5 ]--- > [ 65.386337] Kernel panic - not syncing: Fatal exception in interru= pt > [ 65.386943] Pid: 1518, comm: udp-perf Tainted: G D 2.6.34-= rc5 #1 > [ 65.387557] Call Trace: > [ 65.388011] [] ? panic+0x77/0xf7 > [ 65.388729] [] ? kmsg_dump+0xa6/0x13e > [ 65.389292] [] ? oops_end+0xa7/0xb4 > [ 65.389871] [] ? __kfree_skb+0x11/0x7d > [ 65.390441] [] ? do_invalid_op+0x8b/0x95 > [ 65.391032] [] ? kfree+0x55/0xc6 > [ 65.391587] [] ? > br_nf_pre_routing_finish+0x0/0x25e [bridge] > [ 65.392512] [] ? > br_nf_pre_routing_finish+0x0/0x25e [bridge] > [ 65.393399] [] ? invalid_op+0x1b/0x20 > [ 65.393978] [] ? __kfree_skb+0x11/0x7d > [ 65.394547] [] ? kfree+0x55/0xc6 > [ 65.395091] [] ? __kfree_skb+0x11/0x7d > [ 65.395668] [] ? netif_rx+0xe2/0xee > [ 65.396438] [] ? veth_xmit+0x6e/0xad [veth] > [ 65.397026] [] ? dev_hard_start_xmit+0x221/0x30= 1 > [ 65.397640] [] ? sch_direct_xmit+0x5b/0x15d > [ 65.398222] [] ? __qdisc_run+0xb9/0xd8 > [ 65.398788] [] ? net_tx_action+0xd6/0x149 > [ 65.399365] [] ? __do_softirq+0xdd/0x19f > [ 65.399935] [] ? lapic_next_event+0x18/0x1d > [ 65.400560] [] ? call_softirq+0x1c/0x30 > [ 65.401125] [] ? do_softirq+0x3f/0x79 > [ 65.401708] [] ? irq_exit+0x36/0x76 > [ 65.402267] [] ? smp_apic_timer_interrupt+0x86/= 0x94 > [ 65.402869] [] ? apic_timer_interrupt+0x13/0x20 > [ 65.403463] [] ? cap_sk_getsecid+0x0/0x1 > [ 65.404210] [] ? __xfrm_lookup+0x2/0xb04 > [ 65.404779] [] ? ip_route_output_flow+0x77/0x1c= c > [ 65.405375] [] ? udp_sendmsg+0x32d/0x5f3 > [ 65.405945] [] ? irq_entries_start+0x3c0/0x400 > [ 65.406534] [] ? inet_sendmsg+0x53/0x58 > [ 65.407102] [] ? sock_sendmsg+0x83/0x9b > [ 65.407674] [] ? pick_next_task_fair+0xca/0xd6 > [ 65.408296] [] ? schedule+0x52b/0x593 > [ 65.408854] [] ? apic_timer_interrupt+0xe/0x20 > [ 65.409468] [] ? apic_timer_interrupt+0xe/0x20 > [ 65.410084] [] ? _copy_from_user+0x1b/0x30 > [ 65.410667] [] ? __switch_to+0x1b5/0x2a6 > [ 65.510031] [] ? copy_from_user+0x13/0x25 > [ 65.510818] [] ? sys_sendto+0xd7/0x117 > [ 65.511608] [] ? finish_task_switch+0x34/0xa1 > [ 65.512465] [] ? schedule+0x52b/0x593 > [ 65.513229] [] ? apic_timer_interrupt+0xe/0x20 > [ 65.514040] [] ? system_call_fastpath+0x16/0x1b >=20 > [ 1438.042568] ------------[ cut here ]------------ > [ 1438.043170] kernel BUG at mm/slub.c:2846! > [ 1438.043711] invalid opcode: 0000 [#1] SMP > [ 1438.044531] last sysfs file: /sys/devices/virtual/net/lo/operstate > [ 1438.045148] CPU 1 > [ 1438.045350] Modules linked in: sch_netem veth bridge stp netconsol= e > configfs loop parport_pc tpm_tis tpm snd_pcm psmouse parport tpm_bios > snd_timer snd soundcore snd_page_alloc evdev pcspkr serio_raw > i2c_piix4 i2c_core button processor ext3 jbd mbcache ide_cd_mod cdrom > ide_gd_mod ata_generic ata_piix 8139too libata scsi_mod floppy 8139cp > mii thermal thermal_sys piix ide_core [last unloaded: scsi_wait_scan] > [ 1438.046215] > [ 1438.046215] Pid: 1476, comm: udp-perf Not tainted 2.6.34-rc5 #1 / > [ 1438.046215] RIP: 0010:[] [] > kfree+0x55/0xc6 > [ 1438.046215] RSP: 0018:ffff880001a23d90 EFLAGS: 00010246 > [ 1438.046215] RAX: 0100000000000000 RBX: ffff88007d882200 RCX: 00000= 00000012850 > [ 1438.046215] RDX: ffff88007d882200 RSI: 000000000000000e RDI: ffffe= a0001b972a0 > [ 1438.046215] RBP: ffff88007e20c000 R08: ffff88007d882200 R09: fffff= fffa026c690 > [ 1438.046215] R10: 0000000000000002 R11: ffff88007d882100 R12: fffff= fff8123a77f > [ 1438.046215] R13: 0000000000000032 R14: ffff8800378e0700 R15: ffff8= 8007d882200 > [ 1438.046215] FS: 00007f1c1d07f6f0(0000) GS:ffff880001a20000(0000) > knlGS:0000000000000000 > [ 1438.046215] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 1438.046215] CR2: 00007f6ea9e07310 CR3: 0000000037834000 CR4: 00000= 000000006e0 > [ 1438.046215] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000= 00000000000 > [ 1438.046215] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000= 00000000400 > [ 1438.046215] Process udp-perf (pid: 1476, threadinfo > ffff88007db0e000, task ffff8800379a2350) > [ 1438.046215] Stack: > [ 1438.046215] ffff88007d882200 ffff88007d882200 0000000000000246 > ffffffff8123a77f > [ 1438.046215] <0> ffff880001a32860 ffffffff81241e01 ffffe8ffffa3f430 > ffffe8ffffa3d180 > [ 1438.046215] <0> ffff88007d882200 ffffffffa026c57d 0000000201a30500 > ffff88007d171200 > [ 1438.046215] Call Trace: > [ 1438.046215] > [ 1438.046215] [] ? __kfree_skb+0x11/0x7d > [ 1438.046215] [] ? netif_rx+0xe2/0xee > [ 1438.046215] [] ? veth_xmit+0x6e/0xad [veth] > [ 1438.046215] [] ? dev_hard_start_xmit+0x221/0x30= 1 > [ 1438.046215] [] ? sch_direct_xmit+0x5b/0x15d > [ 1438.046215] [] ? __qdisc_run+0xb9/0xd8 > [ 1438.046215] [] ? net_tx_action+0xd6/0x149 > [ 1438.046215] [] ? __do_softirq+0xdd/0x19f > [ 1438.046215] [] ? lapic_next_event+0x18/0x1d > [ 1438.046215] [] ? call_softirq+0x1c/0x30 > [ 1438.046215] [] ? do_softirq+0x3f/0x79 > [ 1438.046215] [] ? irq_exit+0x36/0x76 > [ 1438.046215] [] ? smp_apic_timer_interrupt+0x86/= 0x94 > [ 1438.046215] [] ? apic_timer_interrupt+0x13/0x20 > [ 1438.046215] > [ 1438.046215] [] ? udp_sendmsg+0x0/0x5f3 > [ 1438.046215] [] ? udp_sendmsg+0x76/0x5f3 > [ 1438.046215] [] ? udp_sendmsg+0x50e/0x5f3 > [ 1438.046215] [] ? sock_sendmsg+0x83/0x9b > [ 1438.046215] [] ? pick_next_task_fair+0xca/0xd6 > [ 1438.046215] [] ? schedule+0x52b/0x593 > [ 1438.046215] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.046215] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.046215] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.046215] [] ? fget_light+0x0/0xa1 > [ 1438.046215] [] ? copy_user_generic_string+0x30/= 0x40 > [ 1438.046215] [] ? copy_from_user+0x13/0x25 > [ 1438.046215] [] ? sys_sendto+0xd7/0x117 > [ 1438.046215] [] ? finish_task_switch+0x34/0xa1 > [ 1438.046215] [] ? schedule+0x52b/0x593 > [ 1438.046215] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.046215] [] ? system_call_fastpath+0x16/0x1b > [ 1438.046215] Code: 83 c3 08 48 83 3b 00 eb ec 48 83 fd 10 0f 86 84 > 00 00 00 48 89 ef e8 f4 e2 ff ff 48 89 c7 48 8b 00 84 c0 78 13 66 a9 > 00 c0 75 04 <0f> 0b eb fe 5b 5d 41 5c e9 fb 57 fd ff 48 8b 4c 24 18 4= c > 8b 47 > [ 1438.046215] RIP [] kfree+0x55/0xc6 > [ 1438.046215] RSP > [ 1438.102706] ---[ end trace ab36062dcf233d6a ]--- > [ 1438.103251] Kernel panic - not syncing: Fatal exception in interru= pt > [ 1438.103912] Pid: 1476, comm: udp-perf Tainted: G D 2.6.34-= rc5 #1 > [ 1438.104563] Call Trace: > [ 1438.105017] [] ? panic+0x77/0xf7 > [ 1438.105718] [] ? kmsg_dump+0xa6/0x13e > [ 1438.106293] [] ? oops_end+0xa7/0xb4 > [ 1438.106866] [] ? __kfree_skb+0x11/0x7d > [ 1438.107451] [] ? do_invalid_op+0x8b/0x95 > [ 1438.108036] [] ? kfree+0x55/0xc6 > [ 1438.108799] [] ? > br_nf_pre_routing_finish+0x0/0x25e [bridge] > [ 1438.109699] [] ? > br_nf_pre_routing_finish+0x0/0x25e [bridge] > [ 1438.110604] [] ? invalid_op+0x1b/0x20 > [ 1438.111172] [] ? __kfree_skb+0x11/0x7d > [ 1438.111753] [] ? kfree+0x55/0xc6 > [ 1438.112359] [] ? __kfree_skb+0x11/0x7d > [ 1438.112952] [] ? netif_rx+0xe2/0xee > [ 1438.113527] [] ? veth_xmit+0x6e/0xad [veth] > [ 1438.114123] [] ? dev_hard_start_xmit+0x221/0x30= 1 > [ 1438.114734] [] ? sch_direct_xmit+0x5b/0x15d > [ 1438.115334] [] ? __qdisc_run+0xb9/0xd8 > [ 1438.115912] [] ? net_tx_action+0xd6/0x149 > [ 1438.116544] [] ? __do_softirq+0xdd/0x19f > [ 1438.117128] [] ? lapic_next_event+0x18/0x1d > [ 1438.117732] [] ? call_softirq+0x1c/0x30 > [ 1438.118420] [] ? do_softirq+0x3f/0x79 > [ 1438.119066] [] ? irq_exit+0x36/0x76 > [ 1438.147879] [] ? smp_apic_timer_interrupt+0x86/= 0x94 > [ 1438.148615] [] ? apic_timer_interrupt+0x13/0x20 > [ 1438.149294] [] ? udp_sendmsg+0x0/0x5f3 > [ 1438.150101] [] ? udp_sendmsg+0x76/0x5f3 > [ 1438.150681] [] ? udp_sendmsg+0x50e/0x5f3 > [ 1438.151276] [] ? sock_sendmsg+0x83/0x9b > [ 1438.151853] [] ? pick_next_task_fair+0xca/0xd6 > [ 1438.152508] [] ? schedule+0x52b/0x593 > [ 1438.153078] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.153687] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.154295] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.154902] [] ? fget_light+0x0/0xa1 > [ 1438.155477] [] ? copy_user_generic_string+0x30/= 0x40 > [ 1438.156097] [] ? copy_from_user+0x13/0x25 > [ 1438.156720] [] ? sys_sendto+0xd7/0x117 > [ 1438.157376] [] ? finish_task_switch+0x34/0xa1 > [ 1438.157970] [] ? schedule+0x52b/0x593 > [ 1438.158557] [] ? apic_timer_interrupt+0xe/0x20 > [ 1438.159153] [] ? system_call_fastpath+0x16/0x1b >=20 > ------------ >=20 > Finally, a panic in 2.6.33. Note that the line in wioch BUG is > triggered is different >=20 > [ 102.442815] ------------[ cut here ]------------ > [ 102.443433] kernel BUG at > /build/mattems-linux-2.6_2.6.33-1~experimental.4-amd64-ieqSsa/linux-2= =2E6-2.6.33-1~experimental.4/debian/build/source_amd64_none/mm/slub.c:2= 969! > [ 102.444874] invalid opcode: 0000 [#1] SMP > [ 102.444958] last sysfs file: /sys/devices/virtual/net/lo/operstate > [ 102.444958] CPU 0 > [ 102.444958] Pid: 4, comm: ksoftirqd/0 Not tainted 2.6.33-2-amd64 #= 1 / > [ 102.444958] RIP: 0010:[] [] > kfree+0x55/0xcb > [ 102.444958] RSP: 0018:ffff880001a03df8 EFLAGS: 00010246 > [ 102.444958] RAX: 0100000000000000 RBX: ffff88007e439000 RCX: 00000= 00000012d70 > [ 102.444958] RDX: 000000000000006a RSI: ffffea0001b76a70 RDI: ffffe= a0000c1a328 > [ 102.444958] RBP: ffff880037533c00 R08: ffff88007e21e500 R09: fffff= fff8162bbe0 > [ 102.444958] R10: 000000037e439e00 R11: ffff88007e439e00 R12: fffff= fff81239cf2 > [ 102.444958] R13: 000000000000006a R14: ffff88007efb3000 R15: ffff8= 8007e21e500 > [ 102.444958] FS: 0000000000000000(0000) GS:ffff880001a00000(0000) > knlGS:0000000000000000 > [ 102.444958] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 102.444958] CR2: 00007fc8e25cd0f0 CR3: 000000007d088000 CR4: 00000= 000000006f0 > [ 102.444958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000= 00000000000 > [ 102.444958] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000= 00000000400 > [ 102.444958] Process ksoftirqd/0 (pid: 4, threadinfo > ffff88007fb78000, task ffff88007fb61500) > [ 102.444958] Stack: > [ 102.444958] ffff88007e439000 ffff88007e439000 0000000000000246 > ffffffff81239cf2 > [ 102.444958] <0> ffff880001a12d80 ffffffff8124125d ffffe8ffff818190 > ffffe8ffff815ee0 > [ 102.444958] <0> ffff88007e439000 ffffffffa025254b ffff880001a10010 > ffff88007ef95200 > [ 102.444958] Call Trace: > [ 102.444958] > [ 102.444958] [] ? __kfree_skb+0x11/0x7d > [ 102.444958] [] ? netif_rx+0xe2/0xee > [ 102.444958] [] ? veth_xmit+0x6e/0xad [veth] > [ 102.444958] [] ? dev_hard_start_xmit+0x221/0x2d= c > [ 102.444958] [] ? sch_direct_xmit+0x5b/0x15d > [ 102.444958] [] ? __qdisc_run+0xb9/0xda > [ 102.444958] [] ? net_tx_action+0xd6/0x149 > [ 102.444958] [] ? __do_softirq+0xdd/0x1a1 > [ 102.444958] [] ? call_softirq+0x1c/0x30 > [ 102.444958] > [ 102.444958] [] ? do_softirq+0x3f/0x79 > [ 102.444958] [] ? run_ksoftirqd+0x6a/0x118 > [ 102.444958] [] ? run_ksoftirqd+0x0/0x118 > [ 102.444958] [] ? kthread+0x79/0x81 > [ 102.444958] [] ? kernel_thread_helper+0x4/0x10 > [ 102.444958] [] ? kthread+0x0/0x81 > [ 102.444958] [] ? kernel_thread_helper+0x0/0x10 > [ 102.444958] Code: 83 c3 08 48 83 3b 00 eb ec 48 83 fd 10 0f 86 89 > 00 00 00 48 89 ef e8 f0 e6 ff ff 48 89 c7 48 8b 00 84 c0 78 13 66 a9 > 00 c0 75 04 <0f> 0b eb fe 5b 5d 41 5c e9 45 5a fd ff 48 8b 4c 24 18 4= c > 8b 4f > [ 102.444958] RIP [] kfree+0x55/0xcb > [ 102.444958] RSP > [ 102.484000] ---[ end trace b1157390d40df1cb ]--- > [ 102.485018] Kernel panic - not syncing: Fatal exception in interru= pt > [ 102.485647] Pid: 4, comm: ksoftirqd/0 Tainted: G D 2.6.33-= 2-amd64 #1 > [ 102.486630] Call Trace: > [ 102.487112] [] ? panic+0x86/0x14b > [ 102.487870] [] ? irq_exit+0x48/0x76 > [ 102.488474] [] ? ret_from_intr+0x0/0x11 > [ 102.489068] [] ? kmsg_dump+0xa6/0x13e > [ 102.489661] [] ? oops_end+0xa7/0xb4 > [ 102.490245] [] ? __kfree_skb+0x11/0x7d > [ 102.490836] [] ? do_invalid_op+0x8b/0x95 > [ 102.491436] [] ? kfree+0x55/0xcb > [ 102.492020] [] ? > br_nf_pre_routing_finish+0x284/0x2a6 [bridge] > [ 102.492942] [] ? > br_nf_pre_routing_finish+0x0/0x2a6 [bridge] > [ 102.493857] [] ? nf_hook_slow+0x62/0xc3 > [ 102.523082] [] ? > br_nf_pre_routing_finish+0x0/0x2a6 [bridge] > [ 102.524008] [] ? invalid_op+0x1b/0x20 > [ 102.524631] [] ? __kfree_skb+0x11/0x7d > [ 102.525225] [] ? kfree+0x55/0xcb > [ 102.525795] [] ? kfree+0x45/0xcb > [ 102.526402] [] ? __kfree_skb+0x11/0x7d > [ 102.526992] [] ? netif_rx+0xe2/0xee > [ 102.527576] [] ? veth_xmit+0x6e/0xad [veth] > [ 102.528199] [] ? dev_hard_start_xmit+0x221/0x2d= c > [ 102.528821] [] ? sch_direct_xmit+0x5b/0x15d > [ 102.529429] [] ? __qdisc_run+0xb9/0xda > [ 102.530018] [] ? net_tx_action+0xd6/0x149 > [ 102.530618] [] ? __do_softirq+0xdd/0x1a1 > [ 102.531214] [] ? call_softirq+0x1c/0x30 > [ 102.531804] [] ? do_softirq+0x3f/0x79 > [ 102.532572] [] ? run_ksoftirqd+0x6a/0x118 > [ 102.533169] [] ? run_ksoftirqd+0x0/0x118 > [ 102.533764] [] ? kthread+0x79/0x81 > [ 102.534340] [] ? kernel_thread_helper+0x4/0x10 > [ 102.534954] [] ? kthread+0x0/0x81 > [ 102.535526] [] ? kernel_thread_helper+0x0/0x10 >=20 Could you please try following patch ? Thanks [PATCH] veth: Dont kfree_skb() after dev_forward_skb() In case of congestion, dev_forward_skb() already free the skb Reported-by: Mart=C3=ADn Ferrari Signed-off-by: Eric Dumazet --- diff --git a/drivers/net/veth.c b/drivers/net/veth.c index f9f0730..5ec542d 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -187,7 +187,6 @@ tx_drop: return NETDEV_TX_OK; =20 rx_drop: - kfree_skb(skb); rcv_stats->rx_dropped++; return NETDEV_TX_OK; }