WARNING: CPU: 0 PID: 1764 at kernel/fork.c:676 __mmdrop+0x25e/0x320 kernel/fork.c:676
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 1764 Comm: syz-executor.4 Not tainted 5.2.0-rc6-next-20190627 #24
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:986
RIP: 0010:__mmdrop+0x25e/0x320 kernel/fork.c:676
Code: 58 14 69 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 48 6d 2f 00 4c 89 ef e8 80 c6 2b 00 eb d2 e8 39 6d 2f 00 0f 0b e8 32 6d 2f 00 <0f> 0b e9 fa fd ff ff e8 26 6d 2f 00 0f 0b e9 2b fe ff ff e8 1a 6d
RSP: 0018:ffff888201a3fa88 EFLAGS: 00010212
RAX: 0000000000040000 RBX: ffff888086106680 RCX: ffffc9001353b000
RDX: 00000000000094dd RSI: ffffffff8142f0ce RDI: ffff888086106aa8
RBP: ffff888201a3fab0 R08: ffff888086106680 R09: ffffed1014284cdc
R10: ffffed1014284cdb R11: ffff8880a14266df R12: ffff8880a1426680
R13: ffff8880a14266dc R14: ffff888055423250 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+0x251/0x2d0 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459519
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:00007fee26293c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000459519
RDX: 0000000020000080 RSI: 000000004028af11 RDI: 0000000000000003
RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fee262946d4
R13: 00000000004c43b9 R14: 00000000004d8330 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..