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WARNING: CPU: 0 PID: 12 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: 12 Comm: kworker/0:1 Not tainted 5.7.0-rc7-next-20200529-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+0x2f/0x3a kernel/panic.c:600
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:105 [inline]
 fixup_bug arch/x86/kernel/traps.c:100 [inline]
 do_error_trap+0x153/0x2b0 arch/x86/kernel/traps.c:197
 handle_invalid_op arch/x86/kernel/traps.c:240 [inline]
 __exc_invalid_op arch/x86/kernel/traps.c:246 [inline]
 exc_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:244
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:526
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 a2 d0 d8 fd e8 9d d0 d8 fd <0f> 0b eb c2 4c 89 e7 e8 41 da 17 fe eb dc e8 ba d9 17 fe eb aa 4c
RSP: 0018:ffffc90000d2fcd0 EFLAGS: 00010293
RAX: ffff8880a95f0300 RBX: ffff888092e82000 RCX: ffffffff839a2a9d
RDX: 0000000000000000 RSI: ffffffff839a2b03 RDI: ffff888092e82018
RBP: 0000607f51636e50 R08: ffff8880a95f0300 R09: 0000000000000001
R10: ffffffff8c588b8f R11: fffffbfff18b1171 R12: ffff888092e82008
R13: ffff888092e82100 R14: 0000000000000000 R15: ffff8880ae637600
 io_ring_ctx_free fs/io_uring.c:7480 [inline]
 io_ring_exit_work+0x2f1/0x640 fs/io_uring.c:7538
 process_one_work+0x965/0x1690 kernel/workqueue.c:2268
 worker_thread+0x96/0xe20 kernel/workqueue.c:2414
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Kernel Offset: disabled
Rebooting in 86400 seconds..