[ OK ] Started Daily Cleanup of Temporary Directories. [ OK ] Started Daily apt download activities. [ OK ] Started Daily apt upgrade and clean activities. [ OK ] Reached target Timers. Starting System Logging Service... Starting Permit User Sessions... [ OK ] Started Permit User Sessions. [ OK ] Started System Logging Service. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. [ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.16' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 65.180587][ T7021] IPVS: ftp: loaded support on port[0] = 21 [ 65.220654][ T7021] netlink: 16 bytes leftover after parsing attributes in process `syz-executor398'. [ 65.277744][ T7021] ------------[ cut here ]------------ [ 65.283228][ T7021] refcount_t: underflow; use-after-free. [ 65.290494][ T7021] WARNING: CPU: 1 PID: 7021 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 [ 65.299854][ T7021] Kernel panic - not syncing: panic_on_warn set ... [ 65.306439][ T7021] CPU: 1 PID: 7021 Comm: syz-executor398 Not tainted 5.6.0-syzkaller #0 [ 65.314884][ T7021] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.325143][ T7021] Call Trace: [ 65.328425][ T7021] dump_stack+0x188/0x20d [ 65.332809][ T7021] ? refcount_warn_saturate+0x1a0/0x1e0 [ 65.338357][ T7021] panic+0x2e3/0x75c [ 65.342235][ T7021] ? add_taint.cold+0x16/0x16 [ 65.346896][ T7021] ? __probe_kernel_read+0x188/0x1d0 [ 65.352163][ T7021] ? __warn.cold+0x14/0x35 [ 65.356568][ T7021] ? __warn+0xd5/0x1c8 [ 65.360660][ T7021] ? refcount_warn_saturate+0x1d1/0x1e0 [ 65.366192][ T7021] __warn.cold+0x2f/0x35 [ 65.370456][ T7021] ? refcount_warn_saturate+0x1d1/0x1e0 [ 65.376978][ T7021] report_bug+0x27b/0x2f0 [ 65.381293][ T7021] do_error_trap+0x12b/0x220 [ 65.385885][ T7021] ? refcount_warn_saturate+0x1d1/0x1e0 [ 65.391554][ T7021] do_invalid_op+0x32/0x40 [ 65.395954][ T7021] ? refcount_warn_saturate+0x1d1/0x1e0 [ 65.401507][ T7021] invalid_op+0x23/0x30 [ 65.405691][ T7021] RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 [ 65.411864][ T7021] Code: e9 db fe ff ff 48 89 df e8 3c 95 1e fe e9 8a fe ff ff e8 02 81 e1 fd 48 c7 c7 c0 c6 71 88 c6 05 a9 fa f1 06 01 e8 97 f5 b2 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 [ 65.431455][ T7021] RSP: 0018:ffffc90001077d38 EFLAGS: 00010286 [ 65.437503][ T7021] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 65.445467][ T7021] RDX: 0000000000000000 RSI: ffffffff815cb321 RDI: fffff5200020ef99 [ 65.453419][ T7021] RBP: 0000000000000003 R08: ffff888086502100 R09: ffffed1015ce66a1 [ 65.461468][ T7021] R10: ffffed1015ce66a0 R11: ffff8880ae733507 R12: ffff8880a21c6040 [ 65.469432][ T7021] R13: ffff8880a21c6044 R14: 00000000000002ab R15: ffff88809000c3c0 [ 65.477408][ T7021] ? vprintk_func+0x81/0x17e [ 65.482008][ T7021] ? refcount_warn_saturate+0x1d1/0x1e0 [ 65.487544][ T7021] free_nsproxy+0x445/0x4a0 [ 65.492025][ T7021] switch_task_namespaces+0xaa/0xc0 [ 65.497213][ T7021] do_exit+0xb2f/0x2dd0 [ 65.501352][ T7021] ? mm_update_next_owner+0x7a0/0x7a0 [ 65.506710][ T7021] ? up_read+0x1ab/0x750 [ 65.510930][ T7021] ? mark_held_locks+0x9f/0xe0 [ 65.515758][ T7021] ? down_read_nested+0x420/0x420 [ 65.520775][ T7021] ? handle_mm_fault+0x491/0xa10 [ 65.525698][ T7021] do_group_exit+0x125/0x340 [ 65.530268][ T7021] __x64_sys_exit_group+0x3a/0x50 [ 65.535282][ T7021] do_syscall_64+0xf6/0x7d0 [ 65.539787][ T7021] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 65.545659][ T7021] RIP: 0033:0x43f998 [ 65.549781][ T7021] Code: Bad RIP value. [ 65.553869][ T7021] RSP: 002b:00007ffef4fb50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 65.562283][ T7021] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998 [ 65.570241][ T7021] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 65.578340][ T7021] RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 65.586295][ T7021] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001 [ 65.594268][ T7021] R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000 [ 65.603691][ T7021] Kernel Offset: disabled [ 65.608124][ T7021] Rebooting in 86400 seconds..