Debian GNU/Linux 7 syzkaller ttyS0

Warning: Permanently added '10.128.0.214' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   41.263405][ T7521] ------------[ cut here ]------------
[   41.269063][ T7521] percpu_ref_kill_and_confirm called more than once on io_ring_ctx_ref_free!
[   41.269283][ T7521] WARNING: CPU: 0 PID: 7521 at lib/percpu-refcount.c:335 percpu_ref_kill_and_confirm+0x341/0x3b0
[   41.288492][ T7521] Kernel panic - not syncing: panic_on_warn set ...
[   41.295232][ T7521] CPU: 0 PID: 7521 Comm: syz-executor922 Not tainted 5.1.0-rc5+ #79
[   41.303179][ T7521] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   41.313223][ T7521] Call Trace:
[   41.316496][ T7521]  dump_stack+0x172/0x1f0
[   41.320812][ T7521]  ? percpu_ref_kill_and_confirm+0x340/0x3b0
[   41.326782][ T7521]  panic+0x2cb/0x65c
[   41.330670][ T7521]  ? __warn_printk+0xf3/0xf3
[   41.335268][ T7521]  ? percpu_ref_kill_and_confirm+0x341/0x3b0
[   41.341226][ T7521]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   41.347446][ T7521]  ? __warn.cold+0x5/0x45
[   41.355113][ T7521]  ? __warn+0xe8/0x1d0
[   41.359162][ T7521]  ? percpu_ref_kill_and_confirm+0x341/0x3b0
[   41.365115][ T7521]  __warn.cold+0x20/0x45
[   41.369336][ T7521]  ? vprintk_emit+0x1ce/0x6d0
[   41.373989][ T7521]  ? percpu_ref_kill_and_confirm+0x341/0x3b0
[   41.379948][ T7521]  report_bug+0x263/0x2b0
[   41.384265][ T7521]  do_error_trap+0x11b/0x200
[   41.388931][ T7521]  do_invalid_op+0x37/0x50
[   41.393341][ T7521]  ? percpu_ref_kill_and_confirm+0x341/0x3b0
[   41.399305][ T7521]  invalid_op+0x14/0x20
[   41.403448][ T7521] RIP: 0010:percpu_ref_kill_and_confirm+0x341/0x3b0
[   41.410970][ T7521] Code: 42 e0 2a 06 01 48 89 fa 48 c1 ea 03 80 3c 02 00 75 76 49 8b 54 24 10 48 c7 c6 a0 71 a1 87 48 c7 c7 40 71 a1 87 e8 ad 92 13 fe <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02
[   41.430554][ T7521] RSP: 0018:ffff888088f07cf0 EFLAGS: 00010082
[   41.436604][ T7521] RAX: 0000000000000000 RBX: 0000607f5142d66b RCX: 0000000000000000
[   41.444557][ T7521] RDX: 0000000000000000 RSI: ffffffff815afcf6 RDI: ffffed10111e0f90
[   41.452506][ T7521] RBP: ffff888088f07d20 R08: ffff888092ebc440 R09: fffffbfff1133639
[   41.460455][ T7521] R10: fffffbfff1133638 R11: ffffffff8899b1c3 R12: ffff888091afee40
[   41.468413][ T7521] R13: ffff888091afee48 R14: 0000000000000286 R15: 0000000000000000
[   41.476390][ T7521]  ? vprintk_func+0x86/0x189
[   41.480958][ T7521]  __io_uring_register+0xa7/0x1fe0
[   41.486048][ T7521]  ? __mutex_lock+0x3cd/0x1310
[   41.490791][ T7521]  ? __x64_sys_io_uring_register+0x182/0x1f0
[   41.496764][ T7521]  ? mutex_trylock+0x1e0/0x1e0
[   41.501507][ T7521]  ? io_sq_wq_submit_work+0x10f0/0x10f0
[   41.507041][ T7521]  ? kasan_check_write+0x14/0x20
[   41.511959][ T7521]  __x64_sys_io_uring_register+0x193/0x1f0
[   41.517746][ T7521]  do_syscall_64+0x103/0x610
[   41.522315][ T7521]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   41.528280][ T7521] RIP: 0033:0x4458c9
[   41.532150][ T7521] Code: e8 bc b7 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 2b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00
[   41.551730][ T7521] RSP: 002b:00007fe49fd4adb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
[   41.560117][ T7521] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 00000000004458c9
[   41.568064][ T7521] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003
[   41.576097][ T7521] RBP: 00000000006dac30 R08: 00007fe49fd4b700 R09: 0000000000000000
[   41.584043][ T7521] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac3c
[   41.592006][ T7521] R13: 00007fff66d1039f R14: 00007fe49fd4b9c0 R15: 20c49ba5e353f7cf
[   41.601308][ T7521] Kernel Offset: disabled
[   41.605713][ T7521] Rebooting in 86400 seconds..