WARNING: CPU: 0 PID: 8776 at kernel/fork.c:676 __mmdrop+0x25e/0x320 /kernel/fork.c:676
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8776 Comm: syz-executor.5 Not tainted 5.2.0-next-20190718 #41
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack /lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 /lib/dump_stack.c:113
 panic+0x2dc/0x755 /kernel/panic.c:219
 __warn.cold+0x20/0x4c /kernel/panic.c:576
 report_bug+0x263/0x2b0 /lib/bug.c:186
 fixup_bug /arch/x86/kernel/traps.c:179 [inline]
 fixup_bug /arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 /arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 /arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 /arch/x86/entry/entry_64.S:1008
RIP: 0010:__mmdrop+0x25e/0x320 /kernel/fork.c:676
Code: b8 71 69 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 18 7e 2f 00 4c 89 ef e8 60 d7 2b 00 eb d2 e8 09 7e 2f 00 0f 0b e8 02 7e 2f 00 <0f> 0b e9 fa fd ff ff e8 f6 7d 2f 00 0f 0b e9 2b fe ff ff e8 ea 7d
RSP: 0018:ffff8880584a7a88 EFLAGS: 00010212
RAX: 0000000000040000 RBX: ffff88809381a280 RCX: ffffc900111c6000
RDX: 00000000000092ed RSI: ffffffff814306ee RDI: ffff88809381a6a8
RBP: ffff8880584a7ab0 R08: ffff88809381a280 R09: ffffed101153087c
R10: ffffed101153087b R11: ffff88808a9843df R12: ffff88808a984380
R13: ffff88808a9843dc R14: ffff888059a62310 R15: 0000000000000002
 mmdrop /./include/linux/sched/mm.h:49 [inline]
 mmu_notifier_unregister+0x368/0x440 /mm/mmu_notifier.c:374
 vhost_dev_cleanup+0x82b/0xc60 /drivers/vhost/vhost.c:962
 vhost_vsock_dev_release+0x324/0x470 /drivers/vhost/vsock.c:627
 __fput+0x2ff/0x890 /fs/file_table.c:280
 ____fput+0x16/0x20 /fs/file_table.c:313
 task_work_run+0x145/0x1c0 /kernel/task_work.c:113
 get_signal+0x2078/0x2500 /kernel/signal.c:2522
 do_signal+0x87/0x1700 /arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x286/0x380 /arch/x86/entry/common.c:159
 prepare_exit_to_usermode /arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath /arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x5a9/0x6a0 /arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459819
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb6d9c25c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000459819
RDX: 00000000200001c0 RSI: 000000004028af11 RDI: 0000000000000003
RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb6d9c266d4
R13: 00000000004c4722 R14: 00000000004d87d0 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..