Warning: Permanently added '10.128.10.31' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 89.727971][ T9766] IPVS: ftp: loaded support on port[0] = 21 [ 89.760630][ T9766] netlink: 16 bytes leftover after parsing attributes in process `syz-executor892'. [ 89.832854][ T9766] ------------[ cut here ]------------ [ 89.838690][ T9766] refcount_t: underflow; use-after-free. [ 89.845020][ T9766] WARNING: CPU: 0 PID: 9766 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 [ 89.854555][ T9766] Kernel panic - not syncing: panic_on_warn set ... [ 89.861156][ T9766] CPU: 0 PID: 9766 Comm: syz-executor892 Not tainted 5.6.0-rc5-syzkaller #0 [ 89.869909][ T9766] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 89.880993][ T9766] Call Trace: [ 89.884452][ T9766] dump_stack+0x188/0x20d [ 89.888912][ T9766] ? refcount_warn_saturate+0x1d0/0x1e0 [ 89.894639][ T9766] panic+0x2e3/0x75c [ 89.898658][ T9766] ? add_taint.cold+0x16/0x16 [ 89.903905][ T9766] ? __probe_kernel_read+0x188/0x1d0 [ 89.909692][ T9766] ? __warn.cold+0x14/0x35 [ 89.914254][ T9766] ? __warn+0xd5/0x1c8 [ 89.918669][ T9766] ? refcount_warn_saturate+0x1d1/0x1e0 [ 89.925261][ T9766] __warn.cold+0x2f/0x35 [ 89.929621][ T9766] ? refcount_warn_saturate+0x1d1/0x1e0 [ 89.935532][ T9766] report_bug+0x27b/0x2f0 [ 89.940058][ T9766] do_error_trap+0x12b/0x220 [ 89.944707][ T9766] ? refcount_warn_saturate+0x1d1/0x1e0 [ 89.951220][ T9766] do_invalid_op+0x32/0x40 [ 89.956128][ T9766] ? refcount_warn_saturate+0x1d1/0x1e0 [ 89.962133][ T9766] invalid_op+0x23/0x30 [ 89.966917][ T9766] RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 [ 89.975780][ T9766] Code: e9 db fe ff ff 48 89 df e8 7c 03 20 fe e9 8a fe ff ff e8 22 39 e3 fd 48 c7 c7 00 b1 51 88 c6 05 a8 7e d2 06 01 e8 87 49 b5 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 [ 89.997654][ T9766] RSP: 0018:ffffc90001fa7d38 EFLAGS: 00010286 [ 90.004717][ T9766] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 90.013435][ T9766] RDX: 0000000000000000 RSI: ffffffff815bfe61 RDI: fffff520003f4f99 [ 90.021967][ T9766] RBP: 0000000000000003 R08: ffff888091c24640 R09: 0000000000000000 [ 90.030965][ T9766] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888093c94040 [ 90.040112][ T9766] R13: ffff888093c94044 R14: 00000000000002aa R15: ffff8880a70d0f00 [ 90.048878][ T9766] ? vprintk_func+0x81/0x17e [ 90.053485][ T9766] ? refcount_warn_saturate+0x1d1/0x1e0 [ 90.059570][ T9766] free_nsproxy+0x445/0x4a0 [ 90.064094][ T9766] switch_task_namespaces+0xaa/0xc0 [ 90.070214][ T9766] do_exit+0xb2f/0x2dd0 [ 90.074368][ T9766] ? mm_update_next_owner+0x7a0/0x7a0 [ 90.079915][ T9766] ? up_read+0x1ab/0x750 [ 90.084340][ T9766] ? mark_held_locks+0x9f/0xe0 [ 90.089459][ T9766] ? down_read_non_owner+0x470/0x470 [ 90.095697][ T9766] ? handle_mm_fault+0x491/0xa10 [ 90.100736][ T9766] do_group_exit+0x125/0x340 [ 90.105824][ T9766] __x64_sys_exit_group+0x3a/0x50 [ 90.111586][ T9766] do_syscall_64+0xf6/0x7d0 [ 90.116259][ T9766] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 90.122325][ T9766] RIP: 0033:0x43f998 [ 90.127248][ T9766] 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 [ 90.147211][ T9766] RSP: 002b:00007ffd0877da08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 90.156563][ T9766] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998 [ 90.164899][ T9766] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 90.173282][ T9766] RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 90.182669][ T9766] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001 [ 90.194388][ T9766] R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000 [ 90.203970][ T9766] Kernel Offset: disabled [ 90.209159][ T9766] Rebooting in 86400 seconds..