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WARNING: CPU: 1 PID: 10206 at lib/percpu-refcount.c:111 percpu_ref_exit+0xab/0xd0 lib/percpu-refcount.c:111
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 10206 Comm: syz-executor347 Not tainted 5.5.0-rc2-next-20191220-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+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:percpu_ref_exit+0xab/0xd0 lib/percpu-refcount.c:111
Code: 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 1d 48 c7 43 08 03 00 00 00 e8 41 c4 d7 fd 5b 41 5c 41 5d 5d c3 e8 35 c4 d7 fd <0f> 0b eb bf 4c 89 ef e8 69 af 15 fe eb d9 e8 c2 ae 15 fe eb a7 4c
RSP: 0018:ffffc900030b7bc0 EFLAGS: 00010293
RAX: ffff8880a4a66380 RBX: ffff888095046010 RCX: ffffffff839d90f2
RDX: 0000000000000000 RSI: ffffffff839d915b RDI: ffff888095046028
RBP: ffffc900030b7bd8 R08: ffff8880a4a66380 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000607f51435308
R13: ffff888095046018 R14: ffff88809927b800 R15: ffff88809927ba28
 io_sqe_files_unregister+0x7d/0x2f0 fs/io_uring.c:4623
 io_ring_ctx_free fs/io_uring.c:5575 [inline]
 io_ring_ctx_wait_and_kill+0x430/0x9a0 fs/io_uring.c:5644
 io_uring_release+0x42/0x50 fs/io_uring.c:5652
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x909/0x2f20 kernel/exit.c:797
 do_group_exit+0x135/0x360 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43fee8
Code: 00 00 be 3c 00 00 00 eb 19 66 0f 1f 84 00 00 00 00 00 48 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 21 f4 48 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 0f 1f 84 00 00 00
RSP: 002b:00007ffc927712d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fee8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004bf770 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 000000000000035b R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..