[....] Starting OpenBSD Secure Shell server: sshd[ 18.816001] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.548472] random: sshd: uninitialized urandom read (32 bytes read) [ 24.799139] random: sshd: uninitialized urandom read (32 bytes read) [ 25.348768] random: sshd: uninitialized urandom read (32 bytes read) [ 104.283745] random: sshd: uninitialized urandom read (32 bytes read) [ 104.410260] sshd (4281) used greatest stack depth: 16776 bytes left Warning: Permanently added '10.128.10.14' (ECDSA) to the list of known hosts. [ 110.170482] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/10 09:29:56 parsed 1 programs [ 111.244967] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/10 09:29:57 executed programs: 0 [ 112.384459] IPVS: ftp: loaded support on port[0] = 21 [ 112.594740] bridge0: port 1(bridge_slave_0) entered blocking state [ 112.601184] bridge0: port 1(bridge_slave_0) entered disabled state [ 112.608493] device bridge_slave_0 entered promiscuous mode [ 112.625146] bridge0: port 2(bridge_slave_1) entered blocking state [ 112.631510] bridge0: port 2(bridge_slave_1) entered disabled state [ 112.638583] device bridge_slave_1 entered promiscuous mode [ 112.654686] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 112.671714] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 112.713852] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 112.732933] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 112.797151] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 112.804367] team0: Port device team_slave_0 added [ 112.820530] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 112.827609] team0: Port device team_slave_1 added [ 112.843133] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 112.860903] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 112.878370] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 112.896140] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 113.021134] bridge0: port 2(bridge_slave_1) entered blocking state [ 113.027564] bridge0: port 2(bridge_slave_1) entered forwarding state [ 113.034532] bridge0: port 1(bridge_slave_0) entered blocking state [ 113.040905] bridge0: port 1(bridge_slave_0) entered forwarding state [ 113.501804] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 113.507912] 8021q: adding VLAN 0 to HW filter on device bond0 [ 113.551970] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 113.563306] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 113.609965] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 113.616596] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 113.625330] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 113.672482] 8021q: adding VLAN 0 to HW filter on device team0 [ 113.969121] [ 113.970766] ====================================================== [ 113.977062] WARNING: possible circular locking dependency detected [ 113.983359] 4.19.0-rc2-next-20180904+ #55 Not tainted [ 113.988524] ------------------------------------------------------ [ 113.994819] syz-executor0/4555 is trying to acquire lock: [ 114.000332] 00000000c2b75acb ((wq_completion)bond_dev->name){+.+.}, at: flush_workqueue+0x2db/0x1e10 [ 114.009596] [ 114.009596] but task is already holding lock: [ 114.015545] 00000000867a356e (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 114.023307] [ 114.023307] which lock already depends on the new lock. [ 114.023307] [ 114.031609] [ 114.031609] the existing dependency chain (in reverse order) is: [ 114.039207] [ 114.039207] -> #2 (rtnl_mutex){+.+.}: [ 114.044481] __mutex_lock+0x171/0x1700 [ 114.048870] mutex_lock_nested+0x16/0x20 [ 114.053439] rtnl_lock+0x17/0x20 [ 114.057319] bond_netdev_notify_work+0x44/0xd0 [ 114.062408] process_one_work+0xc73/0x1aa0 [ 114.067423] worker_thread+0x189/0x13c0 [ 114.071914] kthread+0x35a/0x420 [ 114.075783] ret_from_fork+0x3a/0x50 [ 114.079996] [ 114.079996] -> #1 ((work_completion)(&(&nnw->work)->work)){+.+.}: [ 114.087723] process_one_work+0xc0b/0x1aa0 [ 114.092465] worker_thread+0x189/0x13c0 [ 114.096943] kthread+0x35a/0x420 [ 114.100815] ret_from_fork+0x3a/0x50 [ 114.105031] [ 114.105031] -> #0 ((wq_completion)bond_dev->name){+.+.}: [ 114.112045] lock_acquire+0x1e4/0x4f0 [ 114.116356] flush_workqueue+0x30a/0x1e10 [ 114.121061] drain_workqueue+0x2a9/0x640 [ 114.125679] destroy_workqueue+0xc6/0x9d0 [ 114.130353] __alloc_workqueue_key+0xef9/0x1190 [ 114.135524] bond_init+0x269/0x940 [ 114.139566] register_netdevice+0x337/0x1100 [ 114.144489] bond_newlink+0x49/0xa0 [ 114.148616] rtnl_newlink+0xef4/0x1d50 [ 114.153150] rtnetlink_rcv_msg+0x46e/0xc30 [ 114.157888] netlink_rcv_skb+0x172/0x440 [ 114.162487] rtnetlink_rcv+0x1c/0x20 [ 114.166715] netlink_unicast+0x5a0/0x760 [ 114.171280] netlink_sendmsg+0xa18/0xfc0 [ 114.175853] sock_sendmsg+0xd5/0x120 [ 114.180076] ___sys_sendmsg+0x7fd/0x930 [ 114.184587] __sys_sendmsg+0x11d/0x290 [ 114.188979] __x64_sys_sendmsg+0x78/0xb0 [ 114.193544] do_syscall_64+0x1b9/0x820 [ 114.197936] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 114.203629] [ 114.203629] other info that might help us debug this: [ 114.203629] [ 114.211771] Chain exists of: [ 114.211771] (wq_completion)bond_dev->name --> (work_completion)(&(&nnw->work)->work) --> rtnl_mutex [ 114.211771] [ 114.225466] Possible unsafe locking scenario: [ 114.225466] [ 114.231530] CPU0 CPU1 [ 114.236172] ---- ---- [ 114.240809] lock(rtnl_mutex); [ 114.244063] lock((work_completion)(&(&nnw->work)->work)); [ 114.252283] lock(rtnl_mutex); [ 114.258144] lock((wq_completion)bond_dev->name); [ 114.263053] [ 114.263053] *** DEADLOCK *** [ 114.263053] [ 114.269090] 1 lock held by syz-executor0/4555: [ 114.273642] #0: 00000000867a356e (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 114.281787] [ 114.281787] stack backtrace: [ 114.286265] CPU: 0 PID: 4555 Comm: syz-executor0 Not tainted 4.19.0-rc2-next-20180904+ #55 [ 114.294641] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 114.304036] Call Trace: [ 114.306617] dump_stack+0x1c9/0x2b4 [ 114.310226] ? dump_stack_print_info.cold.2+0x52/0x52 [ 114.315402] ? vprintk_func+0x81/0x117 [ 114.319277] print_circular_bug.isra.34.cold.55+0x1bd/0x27d [ 114.324970] ? save_trace+0xe0/0x290 [ 114.328691] __lock_acquire+0x3449/0x5020 [ 114.332837] ? mark_held_locks+0x160/0x160 [ 114.337053] ? __lock_is_held+0xb5/0x140 [ 114.341108] ? update_curr+0x344/0xba0 [ 114.344971] ? __account_cfs_rq_runtime+0x770/0x770 [ 114.350008] ? mark_held_locks+0x160/0x160 [ 114.354237] ? lock_downgrade+0x8f0/0x8f0 [ 114.358364] lock_acquire+0x1e4/0x4f0 [ 114.362144] ? flush_workqueue+0x2db/0x1e10 [ 114.366446] ? lock_release+0x9f0/0x9f0 [ 114.370395] ? lockdep_init_map+0x9/0x10 [ 114.374437] ? __init_waitqueue_head+0x9e/0x150 [ 114.379081] ? init_wait_entry+0x1c0/0x1c0 [ 114.383295] flush_workqueue+0x30a/0x1e10 [ 114.387419] ? flush_workqueue+0x2db/0x1e10 [ 114.391718] ? lock_acquire+0x1e4/0x4f0 [ 114.395675] ? drain_workqueue+0xa9/0x640 [ 114.399799] ? lock_release+0x9f0/0x9f0 [ 114.403755] ? check_same_owner+0x340/0x340 [ 114.408055] ? __queue_delayed_work+0x390/0x390 [ 114.412701] ? graph_lock+0x170/0x170 [ 114.416482] ? kasan_check_write+0x14/0x20 [ 114.420697] ? __mutex_lock+0x6d0/0x1700 [ 114.424735] ? drain_workqueue+0xa9/0x640 [ 114.428858] ? graph_lock+0x170/0x170 [ 114.432633] ? print_usage_bug+0xc0/0xc0 [ 114.436673] ? find_held_lock+0x36/0x1c0 [ 114.440712] ? lock_downgrade+0x8f0/0x8f0 [ 114.444836] ? graph_lock+0x170/0x170 [ 114.448611] ? graph_lock+0x170/0x170 [ 114.452386] ? find_held_lock+0x36/0x1c0 [ 114.456483] ? kasan_check_write+0x14/0x20 [ 114.460706] ? __mutex_unlock_slowpath+0x197/0x8c0 [ 114.465620] ? wait_for_completion+0x8d0/0x8d0 [ 114.470249] ? do_raw_spin_unlock+0xa7/0x2f0 [ 114.474766] ? trace_hardirqs_on+0x2c0/0x2c0 [ 114.479154] drain_workqueue+0x2a9/0x640 [ 114.483192] ? drain_workqueue+0x2a9/0x640 [ 114.487405] ? flush_workqueue+0x1e10/0x1e10 [ 114.491792] ? save_stack+0xa9/0xd0 [ 114.495394] ? save_stack+0x43/0xd0 [ 114.498998] ? __kasan_slab_free+0x11a/0x170 [ 114.503384] ? kasan_slab_free+0xe/0x10 [ 114.507333] ? print_usage_bug+0xc0/0xc0 [ 114.511372] ? bond_init+0x269/0x940 [ 114.515070] ? register_netdevice+0x337/0x1100 [ 114.519634] ? bond_newlink+0x49/0xa0 [ 114.523410] ? rtnl_newlink+0xef4/0x1d50 [ 114.527448] ? rtnetlink_rcv_msg+0x46e/0xc30 [ 114.531834] ? netlink_rcv_skb+0x172/0x440 [ 114.536054] ? rtnetlink_rcv+0x1c/0x20 [ 114.539919] ? netlink_unicast+0x5a0/0x760 [ 114.544131] ? netlink_sendmsg+0xa18/0xfc0 [ 114.548340] ? sock_sendmsg+0xd5/0x120 [ 114.552209] destroy_workqueue+0xc6/0x9d0 [ 114.556335] ? kasan_check_write+0x14/0x20 [ 114.560545] ? wq_watchdog_timer_fn+0x830/0x830 [ 114.565190] ? mark_held_locks+0xc9/0x160 [ 114.569318] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 114.574398] ? kfree+0x111/0x210 [ 114.577741] ? kfree+0x111/0x210 [ 114.581081] ? lockdep_hardirqs_on+0x421/0x5c0 [ 114.585637] ? trace_hardirqs_on+0xbd/0x2c0 [ 114.589942] ? init_rescuer.part.26+0x155/0x190 [ 114.594588] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 114.599675] ? __kasan_slab_free+0x131/0x170 [ 114.604069] ? init_rescuer.part.26+0x155/0x190 [ 114.608719] __alloc_workqueue_key+0xef9/0x1190 [ 114.613370] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 114.618923] ? workqueue_sysfs_register+0x3f0/0x3f0 [ 114.623924] ? put_dec+0xf0/0xf0 [ 114.627266] ? format_decode+0x1b1/0xaf0 [ 114.631304] ? set_precision+0xe0/0xe0 [ 114.635182] ? simple_strtoll+0xa0/0xa0 [ 114.639147] ? graph_lock+0x170/0x170 [ 114.642993] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 114.648533] ? vsnprintf+0x20d/0x1b60 [ 114.652311] ? find_held_lock+0x36/0x1c0 [ 114.656349] ? lock_downgrade+0x8f0/0x8f0 [ 114.660476] ? kasan_check_read+0x11/0x20 [ 114.664604] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 114.669256] bond_init+0x269/0x940 [ 114.672794] ? __dev_get_by_name+0x170/0x170 [ 114.677193] ? bond_arp_rcv+0x11c0/0x11c0 [ 114.681318] ? check_same_owner+0x340/0x340 [ 114.685616] ? rcu_note_context_switch+0x680/0x680 [ 114.690529] ? bond_arp_rcv+0x11c0/0x11c0 [ 114.694665] register_netdevice+0x337/0x1100 [ 114.699056] ? netdev_change_features+0x110/0x110 [ 114.703996] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 114.709514] ? ns_capable_common+0x13f/0x170 [ 114.713901] ? ns_capable+0x22/0x30 [ 114.717510] bond_newlink+0x49/0xa0 [ 114.721195] ? bond_changelink+0x2360/0x2360 [ 114.725594] rtnl_newlink+0xef4/0x1d50 [ 114.729462] ? rtnl_link_unregister+0x390/0x390 [ 114.734112] ? print_usage_bug+0xc0/0xc0 [ 114.738152] ? __lock_acquire+0x7fc/0x5020 [ 114.742409] ? print_usage_bug+0xc0/0xc0 [ 114.746453] ? graph_lock+0x170/0x170 [ 114.750230] ? print_usage_bug+0xc0/0xc0 [ 114.754265] ? mark_held_locks+0x160/0x160 [ 114.758478] ? __lock_acquire+0x7fc/0x5020 [ 114.762690] ? lock_acquire+0x1e4/0x4f0 [ 114.766642] ? rtnetlink_rcv_msg+0x412/0xc30 [ 114.771034] ? lock_release+0x9f0/0x9f0 [ 114.774988] ? check_same_owner+0x340/0x340 [ 114.779291] ? mutex_trylock+0x2b0/0x2b0 [ 114.783328] ? __lock_acquire+0x7fc/0x5020 [ 114.787545] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 114.793078] ? refcount_sub_and_test_checked+0x21a/0x350 [ 114.798512] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 114.804070] ? rtnl_get_link+0x170/0x370 [ 114.808118] ? rtnl_dump_all+0x600/0x600 [ 114.812160] ? rcu_is_watching+0x8c/0x150 [ 114.816357] ? rtnl_link_unregister+0x390/0x390 [ 114.821013] rtnetlink_rcv_msg+0x46e/0xc30 [ 114.825227] ? rtnetlink_put_metrics+0x690/0x690 [ 114.829961] netlink_rcv_skb+0x172/0x440 [ 114.834001] ? rtnetlink_put_metrics+0x690/0x690 [ 114.838733] ? netlink_ack+0xbe0/0xbe0 [ 114.842599] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 114.847244] rtnetlink_rcv+0x1c/0x20 [ 114.850932] netlink_unicast+0x5a0/0x760 [ 114.854970] ? netlink_attachskb+0x9a0/0x9a0 [ 114.859356] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 114.864932] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 114.869933] netlink_sendmsg+0xa18/0xfc0 [ 114.873971] ? netlink_unicast+0x760/0x760 [ 114.878183] ? aa_sock_msg_perm.isra.13+0xba/0x160 [ 114.883091] ? apparmor_socket_sendmsg+0x29/0x30 [ 114.887826] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 114.893345] ? security_socket_sendmsg+0x94/0xc0 [ 114.898080] ? netlink_unicast+0x760/0x760 [ 114.902293] sock_sendmsg+0xd5/0x120 [ 114.905983] ___sys_sendmsg+0x7fd/0x930 [ 114.909932] ? copy_msghdr_from_user+0x580/0x580 [ 114.914671] ? lock_downgrade+0x8f0/0x8f0 [ 114.918804] ? __fget_light+0x2f7/0x440 [ 114.922763] ? fget_raw+0x20/0x20 [ 114.926199] ? __fd_install+0x2db/0x880 [ 114.930151] ? get_unused_fd_flags+0x1a0/0x1a0 [ 114.934717] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 114.940228] ? sockfd_lookup_light+0xc5/0x160 [ 114.944703] __sys_sendmsg+0x11d/0x290 [ 114.948566] ? __ia32_sys_shutdown+0x80/0x80 [ 114.952955] ? __x64_sys_futex+0x47f/0x6a0 [ 114.957168] ? do_syscall_64+0x9a/0x820 [ 114.961121] ? do_syscall_64+0x9a/0x820 [ 114.965081] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 114.970163] ? trace_hardirqs_off+0xb8/0x2b0 [ 114.974551] __x64_sys_sendmsg+0x78/0xb0 [ 114.978628] do_syscall_64+0x1b9/0x820 [ 114.982504] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 114.987848] ? syscall_return_slowpath+0x5e0/0x5e0 [ 114.992754] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 114.997745] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 115.002736] ? recalc_sigpending_tsk+0x180/0x180 [ 115.007471] ? kasan_check_write+0x14/0x20 [ 115.011683] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 115.016532] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 115.021697] RIP: 0033:0x457099 [ 115.024868] Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 115.043857] RSP: 002b:00007fc2a3cafc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 115.051688] RAX: ffffffffffffffda RBX: 00007fc2a3cb06d4 RCX: 0000000000457099 [ 115.058945] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004 [ 115.066192] RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 [ 115.073445] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff [ 115.080698] R13: 00000000004d4bf0 R14: 00000000004c9133 R15: 0000000000000000 2018/09/10 09:30:02 executed programs: 128 2018/09/10 09:30:07 executed programs: 391