Starting OpenBSD Secure Shell server... Starting System Logging Service... [ OK ] Started Regular background program processing daemon. [ OK ] Started Daily apt upgrade and clean activities. [ OK ] Reached target Timers. [ OK ] Started Permit User Sessions. [ OK ] Started System Logging Service. [ OK ] Found device /dev/ttyS0. [ 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 Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ 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 '10.128.10.48' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 68.702348][ T7184] IPVS: ftp: loaded support on port[0] = 21 [ 68.743306][ T7184] netlink: 16 bytes leftover after parsing attributes in process `syz-executor595'. [ 68.791120][ T7184] ------------[ cut here ]------------ [ 68.796638][ T7184] refcount_t: underflow; use-after-free. [ 68.803574][ T7184] WARNING: CPU: 1 PID: 7184 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 [ 68.812990][ T7184] Kernel panic - not syncing: panic_on_warn set ... [ 68.819774][ T7184] CPU: 1 PID: 7184 Comm: syz-executor595 Not tainted 5.6.0-syzkaller #0 [ 68.828101][ T7184] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.838330][ T7184] Call Trace: [ 68.841844][ T7184] dump_stack+0x188/0x20d [ 68.846164][ T7184] ? refcount_warn_saturate+0x190/0x1e0 [ 68.851736][ T7184] panic+0x2e3/0x75c [ 68.855642][ T7184] ? add_taint.cold+0x16/0x16 [ 68.860352][ T7184] ? __probe_kernel_read+0x188/0x1d0 [ 68.865635][ T7184] ? __warn.cold+0x14/0x35 [ 68.870090][ T7184] ? __warn+0xd5/0x1c8 [ 68.874167][ T7184] ? refcount_warn_saturate+0x1d1/0x1e0 [ 68.879729][ T7184] __warn.cold+0x2f/0x35 [ 68.884250][ T7184] ? refcount_warn_saturate+0x1d1/0x1e0 [ 68.889794][ T7184] report_bug+0x27b/0x2f0 [ 68.894207][ T7184] do_error_trap+0x12b/0x220 [ 68.898840][ T7184] ? refcount_warn_saturate+0x1d1/0x1e0 [ 68.904536][ T7184] do_invalid_op+0x32/0x40 [ 68.909000][ T7184] ? refcount_warn_saturate+0x1d1/0x1e0 [ 68.914714][ T7184] invalid_op+0x23/0x30 [ 68.918890][ T7184] RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 [ 68.925096][ T7184] Code: e9 db fe ff ff 48 89 df e8 ec 5f 1f fe e9 8a fe ff ff e8 22 9d e2 fd 48 c7 c7 00 a9 51 88 c6 05 86 a4 d1 06 01 e8 27 ac b4 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 [ 68.944736][ T7184] RSP: 0018:ffffc90001077d38 EFLAGS: 00010286 [ 68.950793][ T7184] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 68.958784][ T7184] RDX: 0000000000000000 RSI: ffffffff815c0511 RDI: fffff5200020ef99 [ 68.966916][ T7184] RBP: 0000000000000003 R08: ffff8880a2d5c300 R09: ffffed1015ce6659 [ 68.975013][ T7184] R10: ffffed1015ce6658 R11: ffff8880ae7332c7 R12: ffff8880a2e4e040 [ 68.983133][ T7184] R13: ffff8880a2e4e044 R14: 00000000000002ab R15: ffff888096a3e1c0 [ 68.991122][ T7184] ? vprintk_func+0x81/0x17e [ 68.995864][ T7184] ? refcount_warn_saturate+0x1d1/0x1e0 [ 69.001411][ T7184] free_nsproxy+0x445/0x4a0 [ 69.005978][ T7184] switch_task_namespaces+0xaa/0xc0 [ 69.011196][ T7184] do_exit+0xb2f/0x2dd0 [ 69.015373][ T7184] ? mm_update_next_owner+0x7a0/0x7a0 [ 69.020754][ T7184] ? up_read+0x1ab/0x750 [ 69.024981][ T7184] ? mark_held_locks+0x9f/0xe0 [ 69.029739][ T7184] ? down_read_non_owner+0x470/0x470 [ 69.035034][ T7184] ? handle_mm_fault+0x491/0xa10 [ 69.039981][ T7184] do_group_exit+0x125/0x340 [ 69.044701][ T7184] __x64_sys_exit_group+0x3a/0x50 [ 69.049722][ T7184] do_syscall_64+0xf6/0x7d0 [ 69.054294][ T7184] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 69.060217][ T7184] RIP: 0033:0x43f998 [ 69.064200][ T7184] Code: Bad RIP value. [ 69.068432][ T7184] RSP: 002b:00007fffff79bd48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 69.076832][ T7184] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998 [ 69.084785][ T7184] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 69.092784][ T7184] RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 69.100735][ T7184] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001 [ 69.108706][ T7184] R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000 [ 69.118389][ T7184] Kernel Offset: disabled [ 69.122791][ T7184] Rebooting in 86400 seconds..