INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.12' (ECDSA) to the list of known hosts. 2018/03/29 19:35:19 parsed 1 programs 2018/03/29 19:35:19 executed programs: 0 syzkaller login: [ 28.827400] IPVS: ftp: loaded support on port[0] = 21 [ 28.868744] IPVS: ftp: loaded support on port[0] = 21 [ 28.916763] IPVS: ftp: loaded support on port[0] = 21 [ 28.945573] IPVS: ftp: loaded support on port[0] = 21 [ 28.961533] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 28.962095] [ 28.971507] ============================================ [ 28.976934] WARNING: possible recursive locking detected [ 28.982360] 4.16.0-rc7+ #370 Not tainted [ 28.986392] -------------------------------------------- [ 28.991810] syz-executor0/4450 is trying to acquire lock: [ 28.997311] (rtnl_mutex){+.+.}, at: [<0000000014a7a2fd>] rtnl_lock+0x17/0x20 [ 29.004565] [ 29.004565] but task is already holding lock: [ 29.010506] (rtnl_mutex){+.+.}, at: [<0000000014a7a2fd>] rtnl_lock+0x17/0x20 [ 29.017759] [ 29.017759] other info that might help us debug this: [ 29.024390] Possible unsafe locking scenario: [ 29.024390] [ 29.030415] CPU0 [ 29.032968] ---- [ 29.035520] lock(rtnl_mutex); [ 29.038799] lock(rtnl_mutex); [ 29.042047] [ 29.042047] *** DEADLOCK *** [ 29.042047] [ 29.048074] May be due to missing lock nesting notation [ 29.048074] [ 29.054970] 2 locks held by syz-executor0/4450: [ 29.059606] #0: (rtnl_mutex){+.+.}, at: [<0000000014a7a2fd>] rtnl_lock+0x17/0x20 [ 29.067296] #1: (ipvs->sync_mutex){+.+.}, at: [<00000000fe83a639>] do_ip_vs_set_ctl+0x10f8/0x1cc0 [ 29.076459] [ 29.076459] stack backtrace: [ 29.080929] CPU: 0 PID: 4450 Comm: syz-executor0 Not tainted 4.16.0-rc7+ #370 [ 29.088169] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.097494] Call Trace: [ 29.100059] dump_stack+0x194/0x24d [ 29.103660] ? arch_local_irq_restore+0x53/0x53 [ 29.108302] __lock_acquire+0xe8f/0x3e00 [ 29.112336] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 29.117499] ? account_kernel_stack+0x25e/0x3c0 [ 29.122141] ? __lock_acquire+0x664/0x3e00 [ 29.126346] ? finish_task_switch+0x539/0x7e0 [ 29.130816] ? copy_overflow+0x20/0x20 [ 29.134678] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 29.139843] ? __schedule+0x903/0x1ec0 [ 29.143707] ? __sched_text_start+0x8/0x8 [ 29.147828] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.152297] ? trace_hardirqs_off+0x10/0x10 [ 29.156589] ? trace_hardirqs_on+0xd/0x10 [ 29.160706] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.165186] ? finish_task_switch+0x1c1/0x7e0 [ 29.169653] ? finish_task_switch+0x182/0x7e0 [ 29.174126] ? copy_overflow+0x20/0x20 [ 29.177991] lock_acquire+0x1d5/0x580 [ 29.181764] ? lock_acquire+0x1d5/0x580 [ 29.185710] ? rtnl_lock+0x17/0x20 [ 29.189225] ? lock_release+0xa40/0xa40 [ 29.193173] ? check_same_owner+0x320/0x320 [ 29.197465] ? __schedule+0x1ec0/0x1ec0 [ 29.201413] ? rcu_note_context_switch+0x710/0x710 [ 29.206316] ? __might_sleep+0x95/0x190 [ 29.210262] ? rtnl_lock+0x17/0x20 [ 29.213773] __mutex_lock+0x16f/0x1a80 [ 29.217632] ? rtnl_lock+0x17/0x20 [ 29.221141] ? wait_for_completion_killable+0x63e/0x820 [ 29.226475] ? lock_downgrade+0x980/0x980 [ 29.230593] ? rtnl_lock+0x17/0x20 [ 29.234107] ? mutex_lock_io_nested+0x1900/0x1900 [ 29.238920] ? mark_held_locks+0xaf/0x100 [ 29.243048] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.247516] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 29.252501] ? trace_hardirqs_on+0xd/0x10 [ 29.256621] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.261087] ? wait_for_completion_killable+0x63e/0x820 [ 29.266432] ? wait_for_completion_interruptible_timeout+0x820/0x820 [ 29.272894] ? lock_downgrade+0x980/0x980 [ 29.277015] ? lock_release+0xa40/0xa40 [ 29.280965] ? __kthread_create_on_node+0x127/0x480 [ 29.285960] ? do_raw_spin_trylock+0x190/0x190 [ 29.290514] ? wake_up_q+0xe0/0xe0 [ 29.294029] ? SyS_setsockopt+0x189/0x360 [ 29.298149] ? do_syscall_64+0x281/0x940 [ 29.302186] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 29.307532] ? __kthread_create_on_node+0x36e/0x480 [ 29.312519] ? print_irqtrace_events+0x270/0x270 [ 29.317256] ? kthread_park+0x130/0x130 [ 29.321207] ? lock_release+0xa40/0xa40 [ 29.325155] ? __lock_is_held+0xb6/0x140 [ 29.329189] mutex_lock_nested+0x16/0x20 [ 29.333220] ? mutex_lock_nested+0x16/0x20 [ 29.337426] rtnl_lock+0x17/0x20 [ 29.340767] ip_mc_drop_socket+0x88/0x230 [ 29.344885] inet_release+0x4e/0x1c0 [ 29.348579] sock_release+0x8d/0x1e0 [ 29.352266] start_sync_thread+0x2213/0x2b70 [ 29.356644] ? do_ip_vs_set_ctl+0x10f8/0x1cc0 [ 29.361109] ? ip_vs_process_message_v0+0x870/0x870 [ 29.366099] ? ip_vs_sync_conn+0x3950/0x3950 [ 29.370480] ? lock_downgrade+0x980/0x980 [ 29.374596] ? lock_release+0xa40/0xa40 [ 29.378541] ? trace_hardirqs_off+0x10/0x10 [ 29.382838] ? mutex_spin_on_owner+0x446/0xb50 [ 29.387404] ? find_held_lock+0x35/0x1d0 [ 29.391441] ? __might_fault+0x110/0x1d0 [ 29.395473] ? lock_release+0xa40/0xa40 [ 29.399418] ? check_same_owner+0x320/0x320 [ 29.403725] ? module_unload_free+0x5b0/0x5b0 [ 29.408192] ? __might_sleep+0x95/0x190 [ 29.412144] do_ip_vs_set_ctl+0x1139/0x1cc0 [ 29.416436] ? do_ip_vs_set_ctl+0x1139/0x1cc0 [ 29.420912] ? find_held_lock+0x35/0x1d0 [ 29.424943] ? ip_vs_genl_dump_services+0x440/0x440 [ 29.429935] ? nf_sockopt_find.constprop.0+0x1a7/0x220 [ 29.435181] ? lock_downgrade+0x980/0x980 [ 29.439307] ? __fget+0x342/0x5b0 [ 29.442733] ? lock_downgrade+0x980/0x980 [ 29.446851] ? lock_release+0xa40/0xa40 [ 29.450798] ? __lock_is_held+0xb6/0x140 [ 29.454835] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 29.459654] ? wait_for_completion+0x770/0x770 [ 29.464213] ? __fget+0x36b/0x5b0 [ 29.467658] ? module_unload_free+0x5b0/0x5b0 [ 29.472138] ? iterate_fd+0x3f0/0x3f0 [ 29.475913] ? _raw_spin_unlock_irqrestore+0x31/0xc0 [ 29.480992] ? mutex_unlock+0xd/0x10 [ 29.484681] nf_setsockopt+0x67/0xc0 [ 29.488367] ? nf_setsockopt+0x67/0xc0 [ 29.492227] ip_setsockopt+0x97/0xa0 [ 29.495914] udp_setsockopt+0x45/0x80 [ 29.499686] ipv6_setsockopt+0xa0/0x130 [ 29.503631] udpv6_setsockopt+0x45/0x80 [ 29.507577] sock_common_setsockopt+0x95/0xd0 [ 29.512047] SyS_setsockopt+0x189/0x360 [ 29.515993] ? SyS_recv+0x40/0x40 [ 29.519423] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 29.524931] ? do_syscall_64+0xb7/0x940 [ 29.528874] ? SyS_recv+0x40/0x40 [ 29.532314] do_syscall_64+0x281/0x940 [ 29.536171] ? __do_page_fault+0xc90/0xc90 [ 29.540375] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.544844] ? finish_task_switch+0x1c1/0x7e0 [ 29.549308] ? syscall_return_slowpath+0x550/0x550 [ 29.554205] ? syscall_return_slowpath+0x2ac/0x550 [ 29.559104] ? prepare_exit_to_usermode+0x350/0x350 [ 29.564092] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 29.569426] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.574240] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 29.579419] RIP: 0033:0x4548b9 [ 29.582581] RSP: 002b:00007fd65baf3c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 29.590258] RAX: ffffffffffffffda RBX: 00007fd65baf46d4 RCX: 00000000004548b9 [ 29.597500] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000008 [ 29.604740] RBP: 000000000072bea0 R08: 0000000000000018 R09: 0000000000000000 [ 29.612554] R10: 0000000020000100 R11: 0000000000000246 R12: 00000000ffffffff [ 29.619807] R13: 000000000000051b R14: 00000000006f9b28 R15: 0000000000000000