[ 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 '10.128.0.156' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 41.799010][ T7107] IPVS: ftp: loaded support on port[0] = 21 [ 41.831672][ T7107] netlink: 16 bytes leftover after parsing attributes in process `syz-executor178'. [ 41.901539][ T7107] ------------[ cut here ]------------ [ 41.907192][ T7107] refcount_t: underflow; use-after-free. [ 41.913803][ T7107] WARNING: CPU: 1 PID: 7107 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 [ 41.923184][ T7107] Kernel panic - not syncing: panic_on_warn set ... [ 41.929831][ T7107] CPU: 1 PID: 7107 Comm: syz-executor178 Not tainted 5.6.0-syzkaller #0 [ 41.938329][ T7107] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.948407][ T7107] Call Trace: [ 41.951686][ T7107] dump_stack+0x1e9/0x30e [ 41.956181][ T7107] panic+0x264/0x7a0 [ 41.960253][ T7107] ? __warn+0x102/0x210 [ 41.964497][ T7107] ? refcount_warn_saturate+0x15b/0x1a0 [ 41.970168][ T7107] __warn+0x209/0x210 [ 41.974390][ T7107] ? refcount_warn_saturate+0x15b/0x1a0 [ 41.980509][ T7107] report_bug+0x1ac/0x2d0 [ 41.984837][ T7107] do_error_trap+0xca/0x1c0 [ 41.989326][ T7107] do_invalid_op+0x32/0x40 [ 41.993861][ T7107] ? refcount_warn_saturate+0x15b/0x1a0 [ 41.999465][ T7107] invalid_op+0x23/0x30 [ 42.003624][ T7107] RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 [ 42.009801][ T7107] Code: c7 64 03 d1 88 31 c0 e8 33 c6 b2 fd 0f 0b eb 85 e8 3a e9 df fd c6 05 50 26 b1 05 01 48 c7 c7 90 03 d1 88 31 c0 e8 15 c6 b2 fd <0f> 0b e9 64 ff ff ff e8 19 e9 df fd c6 05 30 26 b1 05 01 48 c7 c7 [ 42.029426][ T7107] RSP: 0018:ffffc90001077d98 EFLAGS: 00010246 [ 42.035661][ T7107] RAX: d3df496209ac6b00 RBX: 0000000000000003 RCX: ffff888088166240 [ 42.043755][ T7107] RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 [ 42.051729][ T7107] RBP: 0000000000000003 R08: ffffffff815e07a6 R09: ffffed1015d26618 [ 42.059874][ T7107] R10: ffffed1015d26618 R11: 0000000000000000 R12: ffff8880a704e040 [ 42.067912][ T7107] R13: 0000000000000100 R14: ffff8880a9a7da90 R15: ffff8880a704e044 [ 42.076411][ T7107] ? vprintk_emit+0x2e6/0x3b0 [ 42.081174][ T7107] ? refcount_warn_saturate+0x15b/0x1a0 [ 42.086706][ T7107] free_nsproxy+0x343/0x3b0 [ 42.091350][ T7107] do_exit+0x5ea/0x1f80 [ 42.095497][ T7107] ? __up_read+0x1f1/0x6e0 [ 42.100080][ T7107] do_group_exit+0x15e/0x2c0 [ 42.104675][ T7107] ? trace_irq_disable_rcuidle+0x1f/0x1d0 [ 42.110483][ T7107] __do_sys_exit_group+0x13/0x20 [ 42.115412][ T7107] __se_sys_exit_group+0x10/0x10 [ 42.120427][ T7107] __x64_sys_exit_group+0x37/0x40 [ 42.125472][ T7107] do_syscall_64+0xf3/0x1b0 [ 42.130000][ T7107] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.135976][ T7107] RIP: 0033:0x43f998 [ 42.140070][ T7107] Code: Bad RIP value. [ 42.144595][ T7107] RSP: 002b:00007ffdb6a83e38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 42.153331][ T7107] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998 [ 42.161502][ T7107] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 42.169564][ T7107] RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 42.178125][ T7107] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001 [ 42.186393][ T7107] R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000 [ 42.196336][ T7107] Kernel Offset: disabled [ 42.201869][ T7107] Rebooting in 86400 seconds..