syzbot

 [<ffffffff8151f26a>] vfs_write+0x18a/0x530 fs/read_write.c:538
 [<ffffffff81521959>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff81521959>] SyS_write+0xd9/0x1b0 fs/read_write.c:577
 [<ffffffff837744df>] entry_SYSCALL_64_fastpath+0x1c/0x98
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 5467 Comm: syz-executor2 Not tainted 4.4.115-g55a366596 #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b44be000 task.stack: ffff8800aba28000
RIP: 0010:[<ffffffff82f9d210>]  [<ffffffff82f9d210>] __read_once_size include/linux/compiler.h:218 [inline]
RIP: 0010:[<ffffffff82f9d210>]  [<ffffffff82f9d210>] nfqnl_nf_hook_drop+0x190/0x3a0 net/netfilter/nfnetlink_queue.c:879
RSP: 0018:ffff8800aba2f998  EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000003 RCX: ffffffff82f9d209
RDX: 0000000000010000 RSI: ffffc90002f2d000 RDI: ffffffff84418180
RBP: ffff8800aba2f9c8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff83844400 R11: 1ffff10015745efe R12: dffffc0000000000
R13: ffff8800ac299788 R14: 0000000000000038 R15: 00000000000000b8
FS:  00007ff284c7f700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006fc274 CR3: 00000001d2ac0000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff82f9d180 ffffffff83cc6720 ffff8800ac328000 ffff8800ac299788
 ffff8800ac299788 ffff8800ac299780 ffff8800aba2f9f8 ffffffff82f950ce
 ffffffff82f95010 ffffffff843e37e0 ffff8800ac328ab8 dffffc0000000000
Call Trace:
 [<ffffffff82f950ce>] nf_queue_nf_hook_drop+0xbe/0x1d0 net/netfilter/nf_queue.c:108
 [<ffffffff82f90e2b>] nf_unregister_net_hook+0x2ab/0x350 net/netfilter/core.c:154
 [<ffffffff82f90f70>] nf_unregister_hook_list net/netfilter/core.c:434 [inline]
 [<ffffffff82f90f70>] netfilter_net_exit+0x40/0xb0 net/netfilter/core.c:466
 [<ffffffff82e2ab3e>] ops_exit_list.isra.4+0xae/0x150 net/core/net_namespace.c:134
 [<ffffffff82e2c821>] setup_net+0x221/0x3e0 net/core/net_namespace.c:303
 [<ffffffff82e2de92>] copy_net_ns+0xd2/0x190 net/core/net_namespace.c:369
 [<ffffffff81192e06>] create_new_namespaces+0x2f6/0x610 kernel/nsproxy.c:95
 [<ffffffff811933b1>] copy_namespaces+0x291/0x320 kernel/nsproxy.c:150
 [<ffffffff811270e8>] copy_process+0x1d98/0x6120 kernel/fork.c:1506
 [<ffffffff8112b891>] _do_fork+0x151/0xe00 kernel/fork.c:1784
 [<ffffffff8112c617>] SYSC_clone kernel/fork.c:1893 [inline]
 [<ffffffff8112c617>] SyS_clone+0x37/0x50 kernel/fork.c:1887
 [<ffffffff837744df>] entry_SYSCALL_64_fastpath+0x1c/0x98
Code: df 83 01 00 0f 84 d8 00 00 00 4d 8d 77 38 49 bc 00 00 00 00 00 fc ff df 49 81 c7 b8 00 00 00 e8 67 3b 3c fe 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 0f 85 f4 01 00 00 49 8b 1e e8 7d 8c 2e fe 48 85 
RIP  [<ffffffff82f9d210>] __read_once_size include/linux/compiler.h:218 [inline]
RIP  [<ffffffff82f9d210>] nfqnl_nf_hook_drop+0x190/0x3a0 net/netfilter/nfnetlink_queue.c:879
 RSP <ffff8800aba2f998>
---[ end trace 44ffd1831714d1f7 ]---