------------[ cut here ]------------ percpu_ref_kill_and_confirm called more than once on io_ring_ctx_ref_free! WARNING: CPU: 0 PID: 11501 at lib/percpu-refcount.c:382 percpu_ref_kill_and_confirm+0x169/0x1d0 lib/percpu-refcount.c:382 Modules linked in: CPU: 0 PID: 11501 Comm: syz-executor.1 Not tainted 5.10.0-next-20201222-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:percpu_ref_kill_and_confirm+0x169/0x1d0 lib/percpu-refcount.c:382 Code: 5d 08 48 8d 7b 08 48 89 fa 48 c1 ea 03 80 3c 02 00 75 68 48 8b 53 08 48 c7 c6 a0 56 bf 89 48 c7 c7 c0 55 bf 89 e8 25 09 0a 05 <0f> 0b 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc9000c047a80 EFLAGS: 00010086 RAX: 0000000000000000 RBX: ffff8881417fce00 RCX: 0000000000000000 RDX: ffff88814385b600 RSI: ffffffff815b95f5 RDI: fffff52001808f42 RBP: ffff88802a534000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815b7a4b R11: 0000000000000000 R12: 0000000000000293 R13: 0000000000000000 R14: 0000000000000002 R15: ffff88802ea5b490 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000074b918 CR3: 000000001c88e000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: percpu_ref_kill include/linux/percpu-refcount.h:149 [inline] io_ring_ctx_wait_and_kill+0x31/0x560 fs/io_uring.c:8645 io_uring_release+0x3e/0x50 fs/io_uring.c:8685 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xb89/0x2a00 kernel/exit.c:823 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3e9/0x2160 kernel/signal.c:2770 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e149 Code: Unable to access opcode bytes at RIP 0x45e11f. RSP: 002b:00007f618528dbe8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: fffffffffffffff4 RBX: 0000000020000000 RCX: 000000000045e149 RDX: 0000000020f22000 RSI: 0000000020000000 RDI: 000000000000226e RBP: 000000000119c080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020f22000 R13: 00000000203fe000 R14: 0000000000000000 R15: 0000000000000000