WARNING: CPU: 0 PID: 13354 at mm/rmap.c:235 lock_anon_vma_root mm/rmap.c:235 [inline]
WARNING: CPU: 0 PID: 13354 at mm/rmap.c:235 unlink_anon_vmas+0x523/0xbd0 mm/rmap.c:388
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 13354 Comm: syz-executor4 Not tainted 4.18.0-rc8+ #34
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+0x17c/0x1c0 lib/dump_stack.c:113
 panic+0x3c3/0x9a0 kernel/panic.c:184
 __warn+0x40f/0x580 kernel/panic.c:536
 report_bug+0x6f2/0x840 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0x1c0/0x620 arch/x86/kernel/traps.c:298
 do_invalid_op+0x46/0x50 arch/x86/kernel/traps.c:318
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:999
RIP: 0010:lock_anon_vma_root mm/rmap.c:235 [inline]
RIP: 0010:unlink_anon_vmas+0x523/0xbd0 mm/rmap.c:388
Code: 0f 00 e9 40 fc ff ff 8b 7d b0 e8 b8 ee 0f 00 e9 17 fd ff ff 8b 7d cc e8 ab ee 0f 00 4d 85 ed 0f 84 82 fc ff ff e8 9d 92 b6 ff <0f> 0b 49 83 c5 08 48 8b 45 a0 4c 89 38 8b 4d cc 89 88 88 0c 00 00 
RSP: 0018:ffff88019e25f480 EFLAGS: 00010293
RAX: ffffffff81aef123 RBX: ffff88019bb4c0b0 RCX: ffff880120be8000
RDX: 0000000000000000 RSI: aaaaaaaaaaaab000 RDI: ffffea0009a63c80
RBP: ffff88019e25f528 R08: 0000000000480000 R09: 0000000000000002
R10: 000077ff80000000 R11: 0000000000000000 R12: ffff88019bb4cf78
R13: ffff880100000000 R14: 0000000000000000 R15: 0000000000000000
 free_pgtables+0x2ee/0x6b0 mm/memory.c:642
 exit_mmap+0x510/0x960 mm/mmap.c:3095
 __mmput+0x154/0x5f0 kernel/fork.c:994
 mmput+0xa7/0xe0 kernel/fork.c:1015
 exit_mm+0x6dd/0x790 kernel/exit.c:545
 do_exit+0xbf7/0x3890 kernel/exit.c:854
 do_group_exit+0x1a0/0x350 kernel/exit.c:970
 get_signal+0x1425/0x1ef0 kernel/signal.c:2468
 do_signal+0x120/0x2090 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop arch/x86/entry/common.c:162 [inline]
 prepare_exit_to_usermode+0x273/0x410 arch/x86/entry/common.c:197
 syscall_return_slowpath+0xdb/0x700 arch/x86/entry/common.c:268
 do_syscall_64+0x1ab/0x220 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457089
Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fea6c1f2cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000009300a8 RCX: 0000000000457089
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000009300a8
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000009300ac
hid-generic 0000:0000:0000.0012: hidraw0: <UNKNOWN> HID v0.00 Device [syz1] on syz1
R13: 0000000000a3fb9f R14: 00007fea6c1f39c0 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled