Comment 35 for bug 1824687

I've now got 6 crashes within past 24 hours on the #170+lp1824687v2 testing kernel on a *single* server. It's a production environment, so I'll roll back for now. Two latest backtraces:

[ 6251.834160] Call Trace:
[ 6251.834166] <IRQ>
[ 6251.834174] [<ffffffff8173d130>] skb_release_head_state+0x90/0xb0
[ 6251.834189] [<ffffffff8173dd62>] skb_release_all+0x12/0x30
[ 6251.834203] [<ffffffff8173ddd2>] kfree_skb+0x32/0xa0
[ 6251.834798] [<ffffffff817dca2e>] inet_frag_destroy+0x7e/0x100
[ 6251.835388] [<ffffffffc04b7260>] ? nf_ct_net_exit+0x50/0x50 [nf_defrag_ipv6]
[ 6251.835979] [<ffffffff8182b522>] ip6_expire_frag_queue+0x102/0x110
[ 6251.836562] [<ffffffffc04b727f>] nf_ct_frag6_expire+0x1f/0x30 [nf_defrag_ipv6]
[ 6251.837154] [<ffffffff810f3b57>] call_timer_fn+0x37/0x140
[ 6251.837746] [<ffffffffc04b7260>] ? nf_ct_net_exit+0x50/0x50 [nf_defrag_ipv6]
[ 6251.838350] [<ffffffff810f5464>] run_timer_softirq+0x234/0x330
[ 6251.838961] [<ffffffff8108a339>] __do_softirq+0x109/0x2b0
[ 6251.839574] [<ffffffff8108a655>] irq_exit+0xa5/0xb0
[ 6251.840192] [<ffffffff818660c0>] smp_apic_timer_interrupt+0x50/0x70
[ 6251.843313] [<ffffffff8186383c>] apic_timer_interrupt+0xcc/0xe0
[ 6251.843944] <EOI>
[ 6251.843952] [<ffffffff8173cf29>] ? kfree_skbmem+0x59/0x60
[ 6251.845153] [<ffffffff8126047d>] ? __fsnotify_parent+0x5d/0x130
[ 6251.845744] [<ffffffff8121c0ab>] vfs_read+0xfb/0x130
[ 6251.846316] [<ffffffff8121cd85>] SyS_read+0x55/0xc0
[ 6251.846868] [<ffffffff8186281b>] entry_SYSCALL_64_fastpath+0x22/0xcb

[ 1037.665436] Call Trace:
[ 1037.665442] <IRQ>
[ 1037.665452] [<ffffffffc05131d7>] nf_skb_free+0x17/0x20 [nf_defrag_ipv6]
[ 1037.665469] [<ffffffff817dca23>] inet_frag_destroy+0x73/0x100
[ 1037.665484] [<ffffffffc0513260>] ? nf_ct_net_exit+0x50/0x50 [nf_defrag_ipv6]
[ 1037.665501] [<ffffffff8182b522>] ip6_expire_frag_queue+0x102/0x110
[ 1037.665516] [<ffffffffc051327f>] nf_ct_frag6_expire+0x1f/0x30 [nf_defrag_ipv6]
[ 1037.665534] [<ffffffff810f3b57>] call_timer_fn+0x37/0x140
[ 1037.665548] [<ffffffffc0513260>] ? nf_ct_net_exit+0x50/0x50 [nf_defrag_ipv6]
[ 1037.665569] [<ffffffff810f5464>] run_timer_softirq+0x234/0x330
[ 1037.665585] [<ffffffff8108a339>] __do_softirq+0x109/0x2b0
[ 1037.665598] [<ffffffff8108a655>] irq_exit+0xa5/0xb0
[ 1037.666290] [<ffffffff818660c0>] smp_apic_timer_interrupt+0x50/0x70
[ 1037.666929] [<ffffffff8186383c>] apic_timer_interrupt+0xcc/0xe0
[ 1037.667566] <EOI>
[ 1037.667578] [<ffffffff813af1e0>] ? audit_unix_sk_addr+0x40/0x40
[ 1037.669394] [<ffffffff817cfc20>] ? inet_recvmsg+0xb0/0xb0
[ 1037.670423] [<ffffffff817cfc42>] ? inet_sendmsg+0x22/0xa0
[ 1037.671441] [<ffffffff81735b7e>] sock_sendmsg+0x3e/0x50
[ 1037.672440] [<ffffffff81735c15>] sock_write_iter+0x85/0xf0
[ 1037.673409] [<ffffffff8121b6bf>] do_iter_readv_writev+0x6f/0xa0
[ 1037.674353] [<ffffffff8121c40f>] do_readv_writev+0x18f/0x230
[ 1037.675273] [<ffffffff8121b8c9>] ? __vfs_read+0x29/0x40
[ 1037.676167] [<ffffffff8121c539>] vfs_writev+0x39/0x50
[ 1037.677035] [<ffffffff8121d269>] SyS_writev+0x59/0xf0
[ 1037.677873] [<ffffffff8186281b>] entry_SYSCALL_64_fastpath+0x22/0xcb