Re: [B.A.T.M.A.N.] kernel BUG at net/core/skbuff.c:100

Philipp Psurek
2014-11-24T12:14:39Z

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Hi Martin! Hi all!

Here we go again: same bug with disabled NC.

Now I run the VM with NC and MM disabled until next Monday.

Is this bug Batman-adv or kernel related?

Best regards

Philipp

________________________
Freifunk Rheinland e. V.
– Funkzelle Wuppertal –

SYSTEM MAP: /boot/System.map
DEBUG KERNEL: /usr/src/linux-3.16.7-gentoo/vmlinux (3.16.7-gentoo)
DUMPFILE: vmcore_20141124124133
CPUS: 1
DATE: Mon Nov 24 12:35:05 2014
UPTIME: 1 days, 16:17:07
LOAD AVERAGE: 0.15, 0.21, 0.20
TASKS: 144
NODENAME: wolke
RELEASE: 3.16.7-gentoo
VERSION: #1 SMP Mon Nov 17 03:44:22 CET 2014
MACHINE: x86_64 (2593 Mhz)
MEMORY: 511.6 MB
PANIC: "kernel BUG at net/core/skbuff.c:100!"
PID: 2008
COMMAND: "fastd"
TASK: ffff88001f3dbdb0 [THREAD_INFO: ffff880019214000]
CPU: 0
STATE: TASK_RUNNING (PANIC)

crash> bt
PID: 2008 TASK: ffff88001f3dbdb0 CPU: 0 COMMAND: "fastd"
#0 [ffff88001fc03980] machine_kexec at ffffffff8103a34e
#1 [ffff88001fc039e0] crash_kexec at ffffffff810be503
#2 [ffff88001fc03ab0] oops_end at ffffffff81005fc8
#3 [ffff88001fc03ae0] die at ffffffff81006463
#4 [ffff88001fc03b10] do_trap at ffffffff81002e12
#5 [ffff88001fc03b70] do_error_trap at ffffffff8100316d
#6 [ffff88001fc03c30] do_invalid_op at ffffffff8100394b
#7 [ffff88001fc03c40] invalid_op at ffffffff817f385e
[exception RIP: skb_panic+94]
RIP: ffffffff817eb99d RSP: ffff88001fc03cf8 RFLAGS: 00010296
RAX: 000000000000008b RBX: ffff880000011a40 RCX: 0000000000000092
RDX: 0000000000000083 RSI: 0000000000000046 RDI: 0000000000000246
RBP: ffff88001fc03d18 R8: 0000000000000000 R9: 0000000000000000
R10: 00000000000001af R11: 0000000000000006 R12: 0000000000000564
R13: ffff88001fc03da0 R14: ffff88001f19d600 R15: ffff880013d55062
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#8 [ffff88001fc03d20] skb_put at ffffffff81611bb1
#9 [ffff88001fc03d30] batadv_frag_skb_buffer at ffffffffa001be12 [batman_adv]
#10 [ffff88001fc03d90] batadv_recv_frag_packet at ffffffffa0026273 [batman_adv]
#11 [ffff88001fc03dd0] batadv_batman_skb_recv at ffffffffa001fef5 [batman_adv]
#12 [ffff88001fc03e10] __netif_receive_skb_core at ffffffff81621962
#13 [ffff88001fc03e80] __netif_receive_skb at ffffffff81621e91
#14 [ffff88001fc03ea0] process_backlog at ffffffff81621f7e
#15 [ffff88001fc03ef0] net_rx_action at ffffffff81622731
#16 [ffff88001fc03f50] __do_softirq at ffffffff81053ef8
#17 [ffff88001fc03fb0] do_softirq_own_stack at ffffffff817f3a5c
--- <IRQ stack> ---
#18 [ffff880019217d10] do_softirq_own_stack at ffffffff817f3a5c
[exception RIP: tun_get_user+1056]
RIP: ffffffffa00098f0 RSP: 0000000000000001 RFLAGS: 7fff00000586
RAX: ffffffff816210b4 RBX: ffff880019217d58 RCX: ffff88001932c780
RDX: 0000000000000000 RSI: ffff88001932c780 RDI: 0000000000000586
RBP: ffffffff81620de4 R8: ffff880019217d88 R9: ffff88001932c780
R10: ffff88001932c780 R11: ffffffff81054135 R12: ffff880019217d58
R13: 0000000000000586 R14: ffff88001f19d800 R15: 0000000000000000
ORIG_RAX: ffff880019217e38 CS: 7fff3207c250 SS: 0000
bt: WARNING: possibly bogus exception frame
#19 [ffff880019217e40] tun_chr_aio_write at ffffffffa0009e0b [tun]
#20 [ffff880019217e70] do_sync_write at ffffffff8115c665
#21 [ffff880019217f00] vfs_write at ffffffff8115d38a
#22 [ffff880019217f40] sys_write at ffffffff8115d89a
#23 [ffff880019217f80] system_call_fastpath at ffffffff817f1f29
RIP: 00007ffe0dbc637d RSP: 00007fff3207c4d8 RFLAGS: 00010202
RAX: 0000000000000001 RBX: ffffffff817f1f29 RCX: 0000000000000084
RDX: 0000000000000586 RSI: 00000000007c0f00 RDI: 0000000000000009
RBP: 0000000000000586 R8: 00007ffe0dbaf400 R9: 00007fff3207b998
R10: 00007fff3207c0df R11: 0000000000000293 R12: 00000000007c8278
R13: 0000000000000001 R14: 00000000007c0ef0 R15: 00000000007b96a0
ORIG_RAX: 0000000000000001 CS: 0033 SS: 002b

crash> log
[ … ]
[ 85.585384] random: nonblocking pool is initialized
[ 344.074524] tun: Universal TUN/TAP device driver, 1.6
[ 344.074529] tun: (C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>
[ 345.437185] batman_adv: B.A.T.M.A.N. advanced 2014.3.0 (compatibility version 15) loaded
[ 345.586455] batman_adv: bat0: Adding interface: fastd0
[ 345.586459] batman_adv: bat0: The MTU of interface fastd0 is too small (1426) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
[ 345.586463] batman_adv: bat0: Interface activated: fastd0
[ 345.587575] batman_adv: bat0: orig_interval: Changing from: 1000 to: 5000
[ 345.589193] batman_adv: bat0: bridge_loop_avoidance: Changing from: disabled to: enabled
[ 345.590126] batman_adv: bat0: Changing gw mode from: off to: client
[ 385.143545] ipip: IPv4 over IPv4 tunneling driver
[ 387.153331] dhcpd (2100) used greatest stack depth: 11944 bytes left
[ 420.953976] batman_adv: bat0: Changing gw mode from: client to: server
[ 420.954124] batman_adv: bat0: Changing gateway bandwidth from: '10.0/2.0 MBit' to: '100.0/100.0 MBit'
[ 442.064172] batman_adv: bat0: network_coding: Changing from: enabled to: disabled
[ 737.948219] nf_conntrack: automatic helper assignment is deprecated and it will be removed soon. Use the iptables CT target to attach helpers instead.
[ 6441.957012] dig (23207) used greatest stack depth: 11832 bytes left
[24933.266728] UDP: bad checksum. From _._._._:137 to _._._._ ulen 58
[24933.267969] UDP: bad checksum. From _._._._:137 to _._._._ ulen 58
[79218.832519] UDP: short packet: From _._._._:0 6117/1480 to _._._._:0
[88652.433174] UDP: short packet: From _._._._:0 6117/1480 to _._._._:0
[145027.089070] skbuff: skb_over_panic: text:ffffffffa001be12 len:1448 put:1380 head:ffff88000e4c0c00 data:ffff88000e4c0c62 tail:0x60a end:0x2c0 dev:fastd0
[145027.089388] ------------[ cut here ]------------
[145027.089492] kernel BUG at net/core/skbuff.c:100!
[145027.089590] invalid opcode: 0000 [#1] SMP
[145027.089691] Modules linked in: xt_nat iptable_nat nf_nat_ipv4 nf_nat ipip batman_adv libcrc32c tun crc32c_intel
[145027.089977] CPU: 0 PID: 2008 Comm: fastd Not tainted 3.16.7-gentoo #1
[145027.090003] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[145027.090003] task: ffff88001f3dbdb0 ti: ffff880019214000 task.ti: ffff880019214000
[145027.090003] RIP: 0010:[<ffffffff817eb99d>] [<ffffffff817eb99d>] skb_panic+0x5e/0x60
[145027.090003] RSP: 0018:ffff88001fc03cf8 EFLAGS: 00010296
[145027.090003] RAX: 000000000000008b RBX: ffff880000011a40 RCX: 0000000000000092
[145027.090003] RDX: 0000000000000083 RSI: 0000000000000046 RDI: 0000000000000246
[145027.090003] RBP: ffff88001fc03d18 R08: 0000000000000000 R09: 0000000000000000
[145027.090003] R10: 00000000000001af R11: 0000000000000006 R12: 0000000000000564
[145027.090003] R13: ffff88001fc03da0 R14: ffff88001f19d600 R15: ffff880013d55062
[145027.090003] FS: 00007ffe0e872700(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000
[145027.090003] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[145027.090003] CR2: 00007f410b4a24b0 CR3: 0000000019282000 CR4: 00000000000006f0
[145027.090003] Stack:
[145027.090003] ffff88000e4c0c62 000000000000060a 00000000000002c0 ffff88001932c000
[145027.090003] ffff88001fc03d28 ffffffff81611bb1 ffff88001fc03d88 ffffffffa001be12
[145027.090003] ffff880019cf59c8 ffff880013d5504e ffff88001fc03d78 ffff880000011a40
[145027.090003] Call Trace:
[145027.090003] <IRQ>
[145027.090003]
[145027.090003] [<ffffffff81611bb1>] skb_put+0x41/0x50
[145027.090003] [<ffffffffa001be12>] batadv_frag_skb_buffer+0x272/0x470 [batman_adv]
[145027.090003] [<ffffffffa0026273>] batadv_recv_frag_packet+0x183/0x200 [batman_adv]
[145027.090003] [<ffffffffa001fef5>] batadv_batman_skb_recv+0xd5/0x110 [batman_adv]
[145027.090003] [<ffffffff81621962>] __netif_receive_skb_core+0x222/0x730
[145027.090003] [<ffffffff81621e91>] __netif_receive_skb+0x21/0x70
[145027.090003] [<ffffffff81621f7e>] process_backlog+0x9e/0x170
[145027.090003] [<ffffffff81622731>] net_rx_action+0x141/0x240
[145027.090003] [<ffffffff81053ef8>] __do_softirq+0xe8/0x280
[145027.090003] [<ffffffff817f3a5c>] do_softirq_own_stack+0x1c/0x30
[145027.090003] <EOI>
[145027.090003]
[145027.090003] [<ffffffff81054135>] do_softirq+0x55/0x60
[145027.090003] [<ffffffff816210b4>] netif_rx_ni+0x34/0x70
[145027.090003] [<ffffffffa00098f0>] tun_get_user+0x420/0x840 [tun]
[145027.090003] [<ffffffffa0009e0b>] tun_chr_aio_write+0x7b/0xa0 [tun]
[145027.090003] [<ffffffff8115c665>] do_sync_write+0x55/0x90
[145027.090003] [<ffffffff8115d38a>] vfs_write+0xba/0x1f0
[145027.090003] [<ffffffff8115d89a>] SyS_write+0x4a/0xa0
[145027.090003] [<ffffffff817f1f29>] system_call_fastpath+0x16/0x1b
[145027.090003] Code: 00 00 48 89 44 24 10 8b 87 c0 00 00 00 48 89 44 24 08 48 8b 87 d0 00 00 00 48 c7 c7 30 67 a3 81 48 89 04 24 31 c0 e8 0d 8b ff ff <0f> 0b 55 48 89 f8 48 8b 57 30 48 89 e5 48 8b 0f 5d 80 e5 80 48
[145027.090003] RIP [<ffffffff817eb99d>] skb_panic+0x5e/0x60
[145027.090003] RSP <ffff88001fc03cf8>