Re: 2.6.32-rc5-mmotm1101 - kernel BUG at net/ipv4/tcp_input.c:3707!

[Eric Dumazet <eric.dumazet@gmail.com>]

Valdis.Kletnieks@vt.edu a écrit :
> Seen right after I started 'fetchmail'.  Reproducible - 3 out of 3.
> I'll bisect this tonight if nobody jumps up and yells they know what it is...
> 
> Looking at the traceback, I wonder if we started sending the SYN packet,
> but didn't finish the paperwork before the SYN/ACK came back?
> 
> [   87.269743] ------------[ cut here ]------------
> [   87.270011] kernel BUG at net/ipv4/tcp_input.c:3707!
> [   87.270011] invalid opcode: 0000 [#1] PREEMPT SMP 
> [   87.270011] last sysfs file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0/charge_full
> [   87.270011] CPU 0 
> [   87.270011] Modules linked in: ext4 jbd2 crc16 [last unloaded: microcode]
> [   87.270011] Pid: 2421, comm: fetchmail Not tainted 2.6.32-rc5-mmotm1101 #1 Latitude D820                   
> [   87.270011] RIP: 0010:[<ffffffff813d13c2>]  [<ffffffff813d13c2>] tcp_parse_options+0x62/0x273
> [   87.270011] RSP: 0018:ffff880002603af8  EFLAGS: 00010202
> [   87.270011] RAX: 0000000000000001 RBX: ffff880002603b78 RCX: 000000000000000a
> [   87.270011] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff81ad9fb0
> [   87.270011] RBP: ffff880002603b48 R08: ffff88007e2d9000 R09: 0000000000000001
> [   87.270011] R10: 00000000000006f6 R11: ffff880002603a78 R12: 0000000000000000
> [   87.270011] R13: ffff88007eb0ece8 R14: 0000000000000000 R15: ffff88007e693168
> [   87.270011] FS:  00007fa02ff827c0(0000) GS:ffff880002600000(0000) knlGS:0000000000000000
> [   87.270011] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   87.270011] CR2: 00000032cf7411e0 CR3: 000000007e41d000 CR4: 00000000000006f0
> [   87.270011] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [   87.270011] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> [   87.270011] Process fetchmail (pid: 2421, threadinfo ffff880079234000, task ffff88007d2bc300)
> [   87.270011] Stack:
> [   87.270011]  ffff880002603b48 ffffffff00000001 000000000000000a ffffffff00000000
> [   87.270011] <0> 0000000000000000 ffff88007903bbc0 ffff88007e693168 ffff88007c6eb2c0
> [   87.270011] <0> 0000000000000000 0000000000000000 ffff880002603bc8 ffffffff81430486
> [   87.270011] Call Trace:
> [   87.270011]  <IRQ> 
> [   87.270011]  [<ffffffff81430486>] tcp_v6_conn_request+0x171/0x3cb
> [   87.270011]  [<ffffffff813d3bf8>] tcp_rcv_state_process+0x5f/0x857
> [   87.270011]  [<ffffffff8142ff4d>] tcp_v6_do_rcv+0x313/0x445
> [   87.270011]  [<ffffffff814bd489>] ? _spin_lock_nested+0x42/0x49
> [   87.270011]  [<ffffffff8143155b>] ? tcp_v6_rcv+0x2aa/0x61c
> [   87.270011]  [<ffffffff814316f6>] tcp_v6_rcv+0x445/0x61c
> [   87.270011]  [<ffffffff81414bb9>] ip6_input_finish+0x1bf/0x31f
> [   87.270011]  [<ffffffff81414d66>] ip6_input+0x4d/0x54
> [   87.270011]  [<ffffffff81414502>] ip6_rcv_finish+0x22/0x26
> [   87.270011]  [<ffffffff81414964>] ipv6_rcv+0x45e/0x4b4
> [   87.270011]  [<ffffffff81391662>] netif_receive_skb+0x29e/0x2c8
> [   87.270011]  [<ffffffff81391717>] process_backlog+0x8b/0xc1
> [   87.270011]  [<ffffffff81391e6a>] net_rx_action+0xed/0x2b0
> [   87.270011]  [<ffffffff8108518a>] ? handle_edge_irq+0x16a/0x176
> [   87.270011]  [<ffffffff81041c2a>] __do_softirq+0x127/0x23c
> [   87.270011]  [<ffffffff813922f4>] ? rcu_read_unlock_bh+0x21/0x23
> [   87.270011]  [<ffffffff8100347c>] call_softirq+0x1c/0x34
> [   87.270011]  <EOI> 
> [   87.270011]  [<ffffffff810049cc>] do_softirq+0x44/0xf0
> [   87.270011]  [<ffffffff813922f4>] ? rcu_read_unlock_bh+0x21/0x23
> [   87.270011]  [<ffffffff810414c7>] _local_bh_enable_ip+0x120/0x16e
> [   87.270011]  [<ffffffff8104152d>] local_bh_enable+0xd/0xf
> [   87.270011]  [<ffffffff813922f4>] rcu_read_unlock_bh+0x21/0x23
> [   87.270011]  [<ffffffff81392e10>] dev_queue_xmit+0x3e4/0x408
> [   87.270011]  [<ffffffff81392b70>] ? dev_queue_xmit+0x144/0x408
> [   87.270011]  [<ffffffff8139afa8>] neigh_resolve_output+0x1ef/0x240
> [   87.270011]  [<ffffffff81410f50>] ? ip6_output_finish+0x0/0xfc
> [   87.270011]  [<ffffffff81410fec>] ip6_output_finish+0x9c/0xfc
> [   87.270011]  [<ffffffff8141242d>] ip6_output2+0x2bf/0x2c8
> [   87.270011]  [<ffffffff81413107>] ip6_output+0xcd1/0xce6
> [   87.270011]  [<ffffffff813ab63a>] ? rcu_read_unlock+0x21/0x23
> [   87.270011]  [<ffffffff813ab89b>] ? nf_hook_slow+0xca/0xdb
> [   87.270011]  [<ffffffff81410c9c>] ? dst_output+0x0/0xd
> [   87.270011]  [<ffffffff81410ca7>] dst_output+0xb/0xd
> [   87.270011]  [<ffffffff81413517>] ip6_xmit+0x3fb/0x4d4
> [   87.270011]  [<ffffffff8143dba6>] ? __inet6_hash+0xe5/0x122
> [   87.270011]  [<ffffffff814358b2>] inet6_csk_xmit+0x265/0x274
> [   87.270011]  [<ffffffff811caa4c>] ? _raw_spin_lock+0xe9/0x1ab
> [   87.270011]  [<ffffffff813d557d>] tcp_transmit_skb+0x816/0x85f
> [   87.270011]  [<ffffffff813d6ed5>] tcp_connect+0x3ae/0x409
> [   87.270011]  [<ffffffff8142f74f>] tcp_v6_connect+0x4f0/0x55e
> [   87.270011]  [<ffffffff813e78d0>] inet_stream_connect+0xa0/0x268
> [   87.270011]  [<ffffffff81383c71>] sys_connect+0x75/0x98
> [   87.270011]  [<ffffffff810e2328>] ? path_put+0x1d/0x22
> [   87.270011]  [<ffffffff81066193>] ? trace_hardirqs_on_caller+0x16/0x13c
> [   87.270011]  [<ffffffff8107fdf1>] ? audit_syscall_entry+0xcb/0x19c
> [   87.270011]  [<ffffffff8100246b>] system_call_fastpath+0x16/0x1b
> [   87.270011] Code: e9 04 4d 85 f6 88 4d c0 0f 94 c2 31 c0 45 85 e4 0f 94 c0 21 d0 31 d2 89 c6 89 45 b8 e8 70 6a cc ff 8b 45 b8 8a 4d c0 85 c0 74 04 <0f> 0b eb fe 0f b6 d1 49 83 c7 38 8d 14 95 ec ff ff ff 49 8d 45 
> [   87.270011] RIP  [<ffffffff813d13c2>] tcp_parse_options+0x62/0x273
> [   87.270011]  RSP <ffff880002603af8>
> 


BUG_ON(!estab && !dst); 

Probably comes from commit 022c3f7d82f0f1c68018696f2f027b87b9bb45c2

(Allow tcp_parse_options to consult dst entry)

CC Gilad Ben-Yossef <gilad@codefidence.com> and Ori Finkelman <ori@comsleep.com> for a diagnostic