Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.0.51' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   58.369419][ T7033] IPVS: ftp: loaded support on port[0] = 21
[   58.405891][ T7033] netlink: 16 bytes leftover after parsing attributes in process `syz-executor337'.
[   58.462091][ T7033] ------------[ cut here ]------------
[   58.467596][ T7033] refcount_t: underflow; use-after-free.
[   58.474021][ T7033] WARNING: CPU: 0 PID: 7033 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0
[   58.483404][ T7033] Kernel panic - not syncing: panic_on_warn set ...
[   58.489980][ T7033] CPU: 0 PID: 7033 Comm: syz-executor337 Not tainted 5.6.0-syzkaller #0
[   58.498277][ T7033] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   58.508326][ T7033] Call Trace:
[   58.511598][ T7033]  dump_stack+0x188/0x20d
[   58.515910][ T7033]  ? refcount_warn_saturate+0x120/0x1e0
[   58.521432][ T7033]  panic+0x2e3/0x75c
[   58.525305][ T7033]  ? add_taint.cold+0x16/0x16
[   58.529964][ T7033]  ? __probe_kernel_read+0x188/0x1d0
[   58.535223][ T7033]  ? __warn.cold+0x14/0x35
[   58.539634][ T7033]  ? __warn+0xd5/0x1c8
[   58.543699][ T7033]  ? refcount_warn_saturate+0x1d1/0x1e0
[   58.549784][ T7033]  __warn.cold+0x2f/0x35
[   58.554014][ T7033]  ? refcount_warn_saturate+0x1d1/0x1e0
[   58.559717][ T7033]  report_bug+0x27b/0x2f0
[   58.564037][ T7033]  do_error_trap+0x12b/0x220
[   58.568706][ T7033]  ? refcount_warn_saturate+0x1d1/0x1e0
[   58.574246][ T7033]  do_invalid_op+0x32/0x40
[   58.579616][ T7033]  ? refcount_warn_saturate+0x1d1/0x1e0
[   58.585144][ T7033]  invalid_op+0x23/0x30
[   58.589286][ T7033] RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0
[   58.595419][ T7033] Code: e9 db fe ff ff 48 89 df e8 2c 95 1e fe e9 8a fe ff ff e8 c2 81 e1 fd 48 c7 c7 40 c6 71 88 c6 05 42 be f1 06 01 e8 17 f6 b2 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55
[   58.615016][ T7033] RSP: 0018:ffffc90001677d38 EFLAGS: 00010286
[   58.621149][ T7033] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   58.629097][ T7033] RDX: 0000000000000000 RSI: ffffffff815ca861 RDI: fffff520002cef99
[   58.637046][ T7033] RBP: 0000000000000003 R08: ffff8880950aa200 R09: ffffed1015cc66a1
[   58.644994][ T7033] R10: ffffed1015cc66a0 R11: ffff8880ae633507 R12: ffff888096888040
[   58.652971][ T7033] R13: ffff888096888044 R14: 00000000000002aa R15: ffff88809cac9040
[   58.660982][ T7033]  ? vprintk_func+0x81/0x17e
[   58.665579][ T7033]  ? refcount_warn_saturate+0x1d1/0x1e0
[   58.671115][ T7033]  free_nsproxy+0x445/0x4a0
[   58.675623][ T7033]  switch_task_namespaces+0xaa/0xc0
[   58.680817][ T7033]  do_exit+0xb2f/0x2dd0
[   58.685046][ T7033]  ? mm_update_next_owner+0x7a0/0x7a0
[   58.690404][ T7033]  ? up_read+0x1ab/0x750
[   58.694632][ T7033]  ? mark_held_locks+0x9f/0xe0
[   58.699372][ T7033]  ? down_read_nested+0x420/0x420
[   58.704415][ T7033]  ? handle_mm_fault+0x491/0xa10
[   58.709332][ T7033]  do_group_exit+0x125/0x340
[   58.713903][ T7033]  __x64_sys_exit_group+0x3a/0x50
[   58.718927][ T7033]  do_syscall_64+0xf6/0x7d0
[   58.723525][ T7033]  entry_SYSCALL_64_after_hwframe+0x49/0xb3
[   58.729413][ T7033] RIP: 0033:0x43f998
[   58.733295][ T7033] Code: Bad RIP value.
[   58.737341][ T7033] RSP: 002b:00007ffc19d573a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
[   58.745727][ T7033] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998
[   58.753678][ T7033] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
[   58.761628][ T7033] RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0
[   58.769575][ T7033] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001
[   58.777535][ T7033] R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000
[   58.787106][ T7033] Kernel Offset: disabled
[   58.791524][ T7033] Rebooting in 86400 seconds..