------------[ cut here ]------------
WARNING: CPU: 2 PID: 1216 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: 2 PID: 1216 Comm: kworker/2:2 Not tainted 5.8.0-rc2-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
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+0x2f/0x3a kernel/panic.c:600
 report_bug+0x271/0x2f0 lib/bug.c:198
 exc_invalid_op+0x1b9/0x370 arch/x86/kernel/traps.c:235
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:563
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 c4 d8 fd e8 fd c3 d8 fd <0f> 0b eb c2 4c 89 e7 e8 a1 12 18 fe eb dc e8 1a 12 18 fe eb aa 4c
RSP: 0018:ffffc900040b7cb8 EFLAGS: 00010293
RAX: ffff888027901c80 RBX: ffff888023af4000 RCX: ffffffff839a77ad
RDX: 0000000000000000 RSI: ffffffff839a7813 RDI: ffff888023af4018
RBP: 0000607f810b1368 R08: ffff888027901c80 R09: 0000000000000001
R10: ffffffff8c58db17 R11: fffffbfff18b1b62 R12: ffff888023af4008
R13: ffff888023af41a8 R14: 1ffff1100475e820 R15: ffff888023af4000
 io_ring_ctx_free fs/io_uring.c:7313 [inline]
 io_ring_exit_work+0x39a/0x720 fs/io_uring.c:7381
 process_one_work+0x965/0x1690 kernel/workqueue.c:2269
 worker_thread+0x96/0xe10 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Kernel Offset: disabled