------------[ cut here ]------------ WARNING: CPU: 1 PID: 11957 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: 1 PID: 11957 Comm: syz-executor.2 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:ffffc90001757d68 EFLAGS: 00010293 RAX: ffff88809d5220c0 RBX: ffff8880a14f1e10 RCX: ffffffff838f262d RDX: 0000000000000000 RSI: ffffffff838f2693 RDI: ffff8880a14f1e28 RBP: 0000607f516c80f0 R08: ffff88809d5220c0 R09: ffffed101429e3ca R10: ffffed101429e3c9 R11: ffff8880a14f1e4f R12: ffff8880a14f1e18 R13: ffff8880a27741a0 R14: ffff8880a2774000 R15: ffff88809750a040 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 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x672/0x790 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416211 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffc2b5162b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416211 RDX: 0000001b2e720000 RSI: 000000000000161d RDI: 0000000000000003 RBP: 0000000000000001 R08: 00000000a47b561d R09: 00000000a47b5621 R10: 00007ffc2b516390 R11: 0000000000000293 R12: 000000000076c900 R13: 000000000076c900 R14: 0000000000057864 R15: 000000000076c04c Kernel Offset: disabled Rebooting in 86400 seconds..