------------[ cut here ]------------ WARNING: CPU: 0 PID: 23537 at lib/percpu-refcount.c:112 percpu_ref_exit+0xa3/0xd0 lib/percpu-refcount.c:112 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 23537 Comm: kworker/0:4 Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events io_ring_exit_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:231 __warn.cold+0x20/0x4a kernel/panic.c:600 report_bug+0x1bd/0x210 lib/bug.c:198 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:percpu_ref_exit+0xa3/0xd0 lib/percpu-refcount.c:112 Code: 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 1a 48 c7 43 08 03 00 00 00 5b 5d 41 5c e9 02 d8 d9 fd e8 fd d7 d9 fd <0f> 0b eb c2 4c 89 e7 e8 c1 ec 19 fe eb dc e8 3a ec 19 fe eb aa 4c RSP: 0018:ffffc90006357ca8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88808ca0f000 RCX: ffffffff839a66ad RDX: ffff888033fd2100 RSI: ffffffff839a6713 RDI: ffff88808ca0f018 RBP: 0000607f5109a198 R08: 0000000000000001 R09: ffffffff8c5f0aff R10: 0000000000000000 R11: 0000000000000160 R12: ffff88808ca0f008 R13: 0000000000000000 R14: ffff88808ca0f101 R15: 0000000000000005 io_ring_ctx_free fs/io_uring.c:7890 [inline] io_ring_exit_work+0x466/0x6d0 fs/io_uring.c:7952 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Kernel Offset: disabled Rebooting in 86400 seconds..