------------[ cut here ]------------
WARNING: CPU: 0 PID: 16575 at lib/percpu-refcount.c:111 percpu_ref_exit+0xa3/0xd0 lib/percpu-refcount.c:111
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 16575 Comm: syz-executor.3 Not tainted 5.6.0-rc3-next-20200228-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+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 fixup_bug arch/x86/kernel/traps.c:170 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:percpu_ref_exit+0xa3/0xd0 lib/percpu-refcount.c:111
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 f2 6e e3 fd e8 ed 6e e3 fd <0f> 0b eb c2 4c 89 e7 e8 01 90 20 fe eb dc e8 7a 8f 20 fe eb aa 4c
RSP: 0018:ffffc900061bfc18 EFLAGS: 00010293
RAX: ffff888050528140 RBX: ffff88809fa8e410 RCX: ffffffff838f262d
RDX: 0000000000000000 RSI: ffffffff838f2693 RDI: ffff88809fa8e428
RBP: 0000607f516befd8 R08: ffff888050528140 R09: ffffed1013f51c8a
R10: ffffed1013f51c89 R11: ffff88809fa8e44f R12: ffff88809fa8e418
R13: ffff88809a3451a0 R14: ffff88809a345000 R15: ffff88805464b200
 io_sqe_files_unregister+0x8a/0x2f0 fs/io_uring.c:5412
 io_ring_ctx_free fs/io_uring.c:6408 [inline]
 io_ring_ctx_wait_and_kill+0x4b5/0xa10 fs/io_uring.c:6499
 io_uring_release+0x3e/0x50 fs/io_uring.c:6507
 __fput+0x2da/0x850 fs/file_table.c:280
 task_work_run+0x13f/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xb53/0x2e10 kernel/exit.c:802
 do_group_exit+0x125/0x340 kernel/exit.c:900
 __do_sys_exit_group kernel/exit.c:911 [inline]
 __se_sys_exit_group kernel/exit.c:909 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:909
 do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c849
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff54ac5838 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 000000000045c849
RDX: 0000000000416321 RSI: 0000000000c870f0 RDI: 0000000000000000
RBP: 00000000004c2220 R08: 000000000000000c R09: 00007fff54ac5940
R10: 0000000001529940 R11: 0000000000000246 R12: 000000000076c0e0
R13: 0000000000000001 R14: 0000000000000003 R15: 000000000076c0ec
Kernel Offset: disabled
Rebooting in 86400 seconds..