Comment 5 for bug 1702665

We've switched most of instances in the cluster to c4.large instance type, but another panic occur. Panic happened at different trace, so this may not relate to the first GPF, but pasting log below for information.

Also, t2.small 4.12.x instance is now running 16 hours+, we have not seen panics yet. still keeping eyes how it goes.

[ 7236.612035] BUG: unable to handle kernel paging request at 000000010000000d
[ 7236.614750] IP: [<ffffffff81218247>] free_pipe_info+0x57/0x90
[ 7236.615155] PGD 0
[ 7236.615155] Oops: 0000 [#1] SMP
[ 7236.615155] Modules linked in: veth binfmt_misc xt_nat xt_comment xt_tcpudp ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack x_tables nf_nat nf_conntrack br_netfilter bridge stp llc aufs isofs ppdev input_leds serio_raw parport_pc parport autofs4 btrfs xor raid6_pq crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul psmouse glue_helper ablk_helper cryptd ixgbevf floppy
[ 7236.615155] CPU: 0 PID: 1 Comm: systemd Not tainted 4.4.0-83-generic #106-Ubuntu
[ 7236.615155] Hardware name: Xen HVM domU, BIOS 4.2.amazon 02/16/2017
[ 7236.615155] task: ffff8800eabf0000 ti: ffff8800eabec000 task.ti: ffff8800eabec000
[ 7236.615155] RIP: 0010:[<ffffffff81218247>] [<ffffffff81218247>] free_pipe_info+0x57/0x90
[ 7236.615155] RSP: 0018:ffff8800eabefdf8 EFLAGS: 00010202
[ 7236.615155] RAX: 00000000fffffffd RBX: 0000000000000008 RCX: 000000000000012c
[ 7236.615155] RDX: 0000000000000028 RSI: ffff88005d5cc940 RDI: ffff8800e9840180
[ 7236.615155] RBP: ffff8800eabefe08 R08: 0000000000000000 R09: 0000000000000000
[ 7236.615155] R10: ffff8800e9e125b8 R11: ffff8800b5fc8510 R12: ffff8800e9840180
[ 7236.615155] R13: ffff8800e9e125b8 R14: ffff8800eab44c20 R15: ffff8800e9ee80c0
[ 7236.615155] FS: 00007fb3ddc0c8c0(0000) GS:ffff8800eb600000(0000) knlGS:0000000000000000
[ 7236.615155] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7236.615155] CR2: 000000010000000d CR3: 000000003641f000 CR4: 00000000001406f0
[ 7236.615155] Stack:
[ 7236.615155] ffff8800e9e12640 ffff8800e9840180 ffff8800eabefe30 ffffffff812182dc
[ 7236.615155] ffff8800e9840180 ffff8800b5fc8500 ffff8800e9e125b8 ffff8800eabefe58
[ 7236.615155] ffffffff81218390 ffff8800b5fc8500 0000000000000008 ffff8800e9e125b8
[ 7236.615155] Call Trace:
[ 7236.615155] [<ffffffff812182dc>] put_pipe_info+0x5c/0x70
[ 7236.615155] [<ffffffff81218390>] pipe_release+0xa0/0xb0
[ 7236.615155] [<ffffffff81210f34>] __fput+0xe4/0x220
[ 7236.615155] [<ffffffff812110ae>] ____fput+0xe/0x10
[ 7236.615155] [<ffffffff8109f031>] task_work_run+0x81/0xa0
[ 7236.615155] [<ffffffff81003242>] exit_to_usermode_loop+0xc2/0xd0
[ 7236.615155] [<ffffffff81003c6e>] syscall_return_slowpath+0x4e/0x60
[ 7236.615155] [<ffffffff81840cd0>] int_ret_from_sys_call+0x25/0x8f
[ 7236.615155] Code: 4a e7 ff 41 8b 44 24 48 85 c0 74 2c 48 63 c3 48 8d 14 80 49 8b 84 24 80 00 00 00 48 8d 34 d0 48 8b 46 10 48 85 c0 74 06 4c 89 e7 <ff> 50 10 83 c3 01 41 39 5c 24 48 77 d4 49 8b 7c 24 68 48 85 ff
[ 7236.615155] RIP [<ffffffff81218247>] free_pipe_info+0x57/0x90
[ 7236.615155] RSP <ffff8800eabefdf8>
[ 7236.615155] CR2: 000000010000000d
[ 7236.723319] ---[ end trace aca2b9bb73327372 ]---
[ 7236.726141] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
[ 7236.726141]
[ 7236.729702] Kernel Offset: disabled