Warning: Permanently added '10.128.10.47' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 85.164073][ T9351] IPVS: ftp: loaded support on port[0] = 21 [ 85.196150][ T9351] netlink: 16 bytes leftover after parsing attributes in process `syz-executor842'. [ 85.238865][ T9351] ------------[ cut here ]------------ [ 85.244336][ T9351] refcount_t: underflow; use-after-free. [ 85.250331][ T9351] WARNING: CPU: 0 PID: 9351 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 [ 85.259697][ T9351] Kernel panic - not syncing: panic_on_warn set ... [ 85.266264][ T9351] CPU: 0 PID: 9351 Comm: syz-executor842 Not tainted 5.6.0-rc5-syzkaller #0 [ 85.274928][ T9351] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 85.284961][ T9351] Call Trace: [ 85.288234][ T9351] dump_stack+0x188/0x20d [ 85.292554][ T9351] ? refcount_warn_saturate+0x130/0x1e0 [ 85.298081][ T9351] panic+0x2e3/0x75c [ 85.301963][ T9351] ? add_taint.cold+0x16/0x16 [ 85.306624][ T9351] ? __probe_kernel_read+0x188/0x1d0 [ 85.311887][ T9351] ? __warn.cold+0x14/0x35 [ 85.316319][ T9351] ? __warn+0xd5/0x1c8 [ 85.320373][ T9351] ? refcount_warn_saturate+0x1d1/0x1e0 [ 85.325897][ T9351] __warn.cold+0x2f/0x35 [ 85.330122][ T9351] ? refcount_warn_saturate+0x1d1/0x1e0 [ 85.335659][ T9351] report_bug+0x27b/0x2f0 [ 85.339972][ T9351] do_error_trap+0x12b/0x220 [ 85.344539][ T9351] ? refcount_warn_saturate+0x1d1/0x1e0 [ 85.350075][ T9351] do_invalid_op+0x32/0x40 [ 85.354468][ T9351] ? refcount_warn_saturate+0x1d1/0x1e0 [ 85.359993][ T9351] invalid_op+0x23/0x30 [ 85.364129][ T9351] RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 [ 85.370259][ T9351] Code: e9 db fe ff ff 48 89 df e8 6c 06 20 fe e9 8a fe ff ff e8 32 48 e3 fd 48 c7 c7 40 aa 51 88 c6 05 a4 5d d2 06 01 e8 77 58 b5 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 [ 85.389839][ T9351] RSP: 0018:ffffc900074f7d38 EFLAGS: 00010286 [ 85.395891][ T9351] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 85.403858][ T9351] RDX: 0000000000000000 RSI: ffffffff815bf511 RDI: fffff52000e9ef99 [ 85.411888][ T9351] RBP: 0000000000000003 R08: ffff8880968bc500 R09: 0000000000000000 [ 85.419848][ T9351] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a97ea040 [ 85.427808][ T9351] R13: ffff8880a97ea044 R14: 00000000000002ab R15: ffff8880a818af00 [ 85.435784][ T9351] ? vprintk_func+0x81/0x17e [ 85.440359][ T9351] ? refcount_warn_saturate+0x1d1/0x1e0 [ 85.445885][ T9351] free_nsproxy+0x445/0x4a0 [ 85.450368][ T9351] switch_task_namespaces+0xaa/0xc0 [ 85.455545][ T9351] do_exit+0xb2f/0x2dd0 [ 85.459698][ T9351] ? mm_update_next_owner+0x7a0/0x7a0 [ 85.465047][ T9351] ? up_read+0x1ab/0x750 [ 85.469267][ T9351] ? mark_held_locks+0x9f/0xe0 [ 85.474185][ T9351] ? down_read_non_owner+0x470/0x470 [ 85.479452][ T9351] ? handle_mm_fault+0x491/0xa10 [ 85.484371][ T9351] do_group_exit+0x125/0x340 [ 85.488943][ T9351] __x64_sys_exit_group+0x3a/0x50 [ 85.493946][ T9351] do_syscall_64+0xf6/0x7d0 [ 85.498432][ T9351] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 85.504302][ T9351] RIP: 0033:0x43f998 [ 85.508177][ T9351] Code: 24 38 80 f9 3a 0f 85 5f 01 00 00 48 8d 74 24 34 48 8d 7c 24 38 83 ea 01 89 54 24 34 e8 61 f8 ff ff 83 f8 3c 41 89 c1 0f 87 3d <01> 00 00 8b 4c 24 34 85 c9 0f 8e 59 01 00 00 48 8b 54 24 38 c7 44 [ 85.527760][ T9351] RSP: 002b:00007ffec638a818 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 85.536219][ T9351] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998 [ 85.544220][ T9351] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 85.552201][ T9351] RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 85.560155][ T9351] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001 [ 85.568161][ T9351] R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000 [ 85.577638][ T9351] Kernel Offset: disabled [ 85.582015][ T9351] Rebooting in 86400 seconds..