------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 7627 at lib/refcount.c:28 refcount_warn_saturate+0x135/0x140 lib/refcount.c:28
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 7627 Comm: syz-executor.0 Not tainted 5.4.0-syzkaller #0
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+0x12d/0x187 lib/dump_stack.c:118
 panic+0x22a/0x4e3 kernel/panic.c:221
 __warn.cold.10+0x25/0x2a kernel/panic.c:582
 report_bug+0x1b0/0x270 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x135/0x140 lib/refcount.c:28
Code: bb f4 fd 0f 0b e9 51 ff ff ff 48 89 df e8 83 23 54 fe e9 1f ff ff ff 48 c7 c7 c0 e5 cb 87 c6 05 34 2a 5f 06 01 e8 f3 ba f4 fd <0f> 0b e9 2a ff ff ff 0f 1f 40 00 55 be 04 00 00 00 48 89 e5 41 57
RSP: 0018:ffffc90002917d58 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8880801a9f58 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8a91c4e0
RBP: ffffc90002917d68 R08: ffffed1015d46621 R09: ffffed1015d46621
R10: ffffed1015d46620 R11: ffff8880aea33107 R12: 0000000000000003
R13: ffff8880801a9f00 R14: ffff8880801a9f28 R15: ffff8880801a9f18
 refcount_sub_and_test include/linux/refcount.h:261 [inline]
 refcount_dec_and_test include/linux/refcount.h:281 [inline]
 kref_put include/linux/kref.h:64 [inline]
 put_watch+0x54/0x60 drivers/misc/watch_queue.c:633
 watch_queue_clear drivers/misc/watch_queue.c:826 [inline]
 watch_queue_release+0x275/0xab0 drivers/misc/watch_queue.c:842
 __fput+0x25a/0x770 fs/file_table.c:280
 ____fput+0x9/0x10 fs/file_table.c:313
 task_work_run+0x108/0x180 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x24e/0x2e0 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x4ff/0x5f0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x414211
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffe3a333830 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000414211
RDX: 0000001b2f320000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff
R10: 00007ffe3a333910 R11: 0000000000000293 R12: 000000000075bf20
R13: 000000000000e41e R14: 0000000000760130 R15: 000000000075bf2c
Kernel Offset: disabled
Rebooting in 86400 seconds..