SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
------------[ cut here ]------------
RIP: 0033:0x45c4aa
WARNING: CPU: 1 PID: 20923 at lib/refcount.c:153 refcount_inc lib/refcount.c:153 [inline]
WARNING: CPU: 1 PID: 20923 at lib/refcount.c:153 refcount_inc.cold+0x18/0x1f lib/refcount.c:151
Kernel panic - not syncing: panic_on_warn set ...

RSP: 002b:00007fcaddaeca88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fcaddaecb40 RCX: 000000000045c4aa
RDX: 00007fcaddaecae0 RSI: 0000000020000040 RDI: 00007fcaddaecb00
RBP: 0000000000000000 R08: 00007fcaddaecb40 R09: 00007fcaddaecae0
R10: 0000000000acc4e2 R11: 0000000000000206 R12: 0000000000000004
R13: 00000000004c8dfc R14: 00000000004e0260 R15: 0000000000000003
CPU: 1 PID: 20923 Comm: syz-executor.1 Not tainted 4.14.148 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
kobject: 'event4' (ffff888065f84cb8): kobject_uevent_env
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x197 lib/dump_stack.c:53
 panic+0x1f2/0x426 kernel/panic.c:182
kobject: 'event4' (ffff888065f84cb8): fill_kobj_path: path = '/devices/virtual/input/input720/event4'
 __warn.cold+0x2f/0x36 kernel/panic.c:546
kobject: '(null)' (ffff888065f850e8): kobject_cleanup, parent ffff888065f84cb8
 report_bug+0x216/0x254 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
kobject: '(null)' (ffff888065f850e8): calling ktype release
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:refcount_inc lib/refcount.c:153 [inline]
RIP: 0010:refcount_inc.cold+0x18/0x1f lib/refcount.c:151
RSP: 0018:ffff888058d4f980 EFLAGS: 00010286
RAX: 000000000000002b RBX: 1ffff1100b1a9f3d RCX: 0000000000000000
RDX: 00000000000151a5 RSI: ffffffff814b4025 RDI: ffffed100b1a9f26
RBP: ffff888058d4f988 R08: 000000000000002b R09: ffff8880434d0d60
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888065f8f9e0
R13: 0000000000000000 R14: ffff888096557d40 R15: ffff888092cdeee8
 kref_get include/linux/kref.h:47 [inline]
 kobject_get+0x5b/0x70 lib/kobject.c:596
 cdev_get+0x54/0xa0 fs/char_dev.c:364
 chrdev_open+0x9b/0x590 fs/char_dev.c:409
 do_dentry_open+0x73b/0xeb0 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:891
 do_last fs/namei.c:3425 [inline]
 path_openat+0x8bd/0x3f70 fs/namei.c:3566
 do_filp_open+0x18e/0x250 fs/namei.c:3600
 do_sys_open+0x2c5/0x430 fs/open.c:1084
 SYSC_open fs/open.c:1102 [inline]
 SyS_open+0x2d/0x40 fs/open.c:1097
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x413941
RSP: 002b:00007fa8f6bc77a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000413941
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fa8f6bc7850
RBP: 000000000075bf20 R08: 000000000000000f R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007fa8f6bc86d4
R13: 00000000004c9086 R14: 00000000004e0548 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..