FAULT_INJECTION: forcing a failure.
name fail_futex, interval 1, probability 0, space 0, times 1
input: syz0 as /devices/virtual/input/input307
------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 14661 at lib/refcount.c:153 refcount_inc_checked+0x5d/0x70 lib/refcount.c:153
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 14661 Comm: syz-executor4 Not tainted 4.19.0-rc2+ #228
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+0x1c4/0x2b4 lib/dump_stack.c:113
 panic+0x238/0x4e7 kernel/panic.c:184
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:993
RIP: 0010:refcount_inc_checked+0x5d/0x70 lib/refcount.c:153
Code: 1d c3 81 91 06 31 ff 89 de e8 4f 8c ef fd 84 db 75 df e8 76 8b ef fd 48 c7 c7 60 81 44 88 c6 05 a3 81 91 06 01 e8 23 76 b9 fd <0f> 0b eb c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89
RSP: 0018:ffff88018d2ff5b0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000727a000
RDX: 000000000000d1e8 RSI: ffffffff8164f835 RDI: 0000000000000005
RBP: ffff88018d2ff5b8 R08: ffff880190ace140 R09: 0000000000000006
R10: 0000000000000000 R11: ffff880190ace140 R12: 0000000000000001
R13: ffff8801d264b140 R14: ffff8801c97a0540 R15: ffff8801d264b4c0
 kref_get include/linux/kref.h:47 [inline]
 kobject_get+0x66/0xc0 lib/kobject.c:613
 cdev_get+0x60/0xb0 fs/char_dev.c:358
 chrdev_open+0xc4/0x710 fs/char_dev.c:403
 do_dentry_open+0x499/0x1250 fs/open.c:771
 vfs_open+0xa0/0xd0 fs/open.c:880
 do_last fs/namei.c:3418 [inline]
 path_openat+0x12bf/0x5160 fs/namei.c:3534
 do_filp_open+0x255/0x380 fs/namei.c:3564
 do_sys_open+0x568/0x700 fs/open.c:1063
 __do_sys_open fs/open.c:1081 [inline]
 __se_sys_open fs/open.c:1076 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1076
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x410dd1
Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 b4 17 00 00 c3 48 83 ec 08 e8 8a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 d3 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fe96945d7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000410dd1
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fe96945d850
RBP: 0000000000930140 R08: 000000000000000f R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000ffffffff
R13: 00000000004d7470 R14: 00000000004ca4c6 R15: 0000000000000001
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..