[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.92' (ECDSA) to the list of known hosts. syzkaller login: [ 28.039549] IPVS: ftp: loaded support on port[0] = 21 [ 28.106242] chnl_net:caif_netlink_parms(): no params data found [ 28.179350] bridge0: port 1(bridge_slave_0) entered blocking state [ 28.185893] bridge0: port 1(bridge_slave_0) entered disabled state [ 28.193602] device bridge_slave_0 entered promiscuous mode [ 28.201163] bridge0: port 2(bridge_slave_1) entered blocking state [ 28.207529] bridge0: port 2(bridge_slave_1) entered disabled state [ 28.214940] device bridge_slave_1 entered promiscuous mode [ 28.230999] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 28.239943] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 28.257329] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 28.264474] team0: Port device team_slave_0 added [ 28.270323] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 28.277305] team0: Port device team_slave_1 added [ 28.292386] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 28.298671] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. [ 28.325083] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 28.336476] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 28.343193] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. [ 28.368975] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 28.379797] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready [ 28.387057] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready [ 28.405479] device hsr_slave_0 entered promiscuous mode [ 28.411083] device hsr_slave_1 entered promiscuous mode [ 28.416863] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready [ 28.424559] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready [ 28.482088] bridge0: port 2(bridge_slave_1) entered blocking state [ 28.488515] bridge0: port 2(bridge_slave_1) entered forwarding state [ 28.495193] bridge0: port 1(bridge_slave_0) entered blocking state [ 28.501567] bridge0: port 1(bridge_slave_0) entered forwarding state [ 28.527527] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 28.533626] 8021q: adding VLAN 0 to HW filter on device bond0 [ 28.542372] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 28.551124] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 28.570330] bridge0: port 1(bridge_slave_0) entered disabled state [ 28.577193] bridge0: port 2(bridge_slave_1) entered disabled state [ 28.586638] IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready [ 28.593181] 8021q: adding VLAN 0 to HW filter on device team0 [ 28.601646] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 28.609728] bridge0: port 1(bridge_slave_0) entered blocking state [ 28.616055] bridge0: port 1(bridge_slave_0) entered forwarding state [ 28.625272] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 28.632954] bridge0: port 2(bridge_slave_1) entered blocking state [ 28.639328] bridge0: port 2(bridge_slave_1) entered forwarding state [ 28.652803] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 28.660347] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 28.674081] hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network [ 28.683901] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network [ 28.694217] IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready [ 28.700799] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 28.708785] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 28.716242] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 28.723854] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 28.734189] IPv6: ADDRCONF(NETDEV_UP): vxcan0: link is not ready [ 28.742423] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready [ 28.749115] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready [ 28.758056] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 28.804486] IPv6: ADDRCONF(NETDEV_UP): veth0_virt_wifi: link is not ready [ 28.813810] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 28.841239] IPv6: ADDRCONF(NETDEV_UP): veth0_vlan: link is not ready [ 28.848089] IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready [ 28.855196] IPv6: ADDRCONF(NETDEV_UP): vlan1: link is not ready [ 28.863870] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 28.871340] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 28.878503] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 28.886689] device veth0_vlan entered promiscuous mode [ 28.894637] device veth1_vlan entered promiscuous mode [ 28.900636] IPv6: ADDRCONF(NETDEV_UP): macvlan0: link is not ready [ 28.908860] IPv6: ADDRCONF(NETDEV_UP): macvlan1: link is not ready [ 28.919428] IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready [ 28.928365] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready [ 28.935397] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready [ 28.942680] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 28.954624] device veth0_macvtap entered promiscuous mode [ 28.960978] IPv6: ADDRCONF(NETDEV_UP): macvtap0: link is not ready [ 28.969022] device veth1_macvtap entered promiscuous mode [ 28.976805] IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready [ 28.987462] IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready [ 28.997269] batman_adv: batadv0: Interface activated: batadv_slave_0 [ 29.004220] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 29.012278] IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready [ 29.021781] batman_adv: batadv0: Interface activated: batadv_slave_1 [ 29.029040] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready executing program [ 29.098463] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 29.518041] [ 29.519652] ====================================================== [ 29.525946] WARNING: possible circular locking dependency detected [ 29.532241] 4.14.291-syzkaller #0 Not tainted [ 29.536705] ------------------------------------------------------ [ 29.542996] kworker/u4:4/2850 is trying to acquire lock: [ 29.548421] (&(&gsm->tx_lock)->rlock){-...}, at: [] gsmld_write_wakeup+0x4e/0xd0 [ 29.557588] [ 29.557588] but task is already holding lock: [ 29.563530] (&port_lock_key){-.-.}, at: [] serial8250_handle_irq.part.0+0x20/0x330 [ 29.572898] [ 29.572898] which lock already depends on the new lock. [ 29.572898] [ 29.581183] [ 29.581183] the existing dependency chain (in reverse order) is: [ 29.588772] [ 29.588772] -> #1 (&port_lock_key){-.-.}: [ 29.594376] _raw_spin_lock_irqsave+0x8c/0xc0 [ 29.599367] uart_write_room+0xd5/0x340 [ 29.603839] tty_write_room+0x61/0x80 [ 29.608145] gsmld_write+0x69/0x120 [ 29.612265] tty_write+0x410/0x740 [ 29.616309] __vfs_write+0xe4/0x630 [ 29.620432] __kernel_write+0xf5/0x330 [ 29.624812] write_pipe_buf+0x143/0x1c0 [ 29.629291] __splice_from_pipe+0x326/0x7a0 [ 29.634103] default_file_splice_write+0xc5/0x150 [ 29.639439] direct_splice_actor+0x115/0x160 [ 29.644338] splice_direct_to_actor+0x25a/0x700 [ 29.649499] do_splice_direct+0x164/0x210 [ 29.654151] do_sendfile+0x47f/0xb30 [ 29.658355] SyS_sendfile64+0xff/0x110 [ 29.662751] do_syscall_64+0x1d5/0x640 [ 29.667131] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.672833] [ 29.672833] -> #0 (&(&gsm->tx_lock)->rlock){-...}: [ 29.679220] lock_acquire+0x170/0x3f0 [ 29.683513] _raw_spin_lock_irqsave+0x8c/0xc0 [ 29.688502] gsmld_write_wakeup+0x4e/0xd0 [ 29.693140] tty_wakeup+0xc3/0xf0 [ 29.697095] tty_port_default_wakeup+0x26/0x40 [ 29.702172] serial8250_tx_chars+0x3fe/0xc70 [ 29.707074] serial8250_handle_irq.part.0+0x28d/0x330 [ 29.712756] serial8250_default_handle_irq+0x8a/0x1f0 [ 29.718438] serial8250_interrupt+0xf3/0x210 [ 29.723342] __handle_irq_event_percpu+0xee/0x7f0 [ 29.728681] handle_irq_event+0xed/0x240 [ 29.733234] handle_edge_irq+0x224/0xc40 [ 29.737785] handle_irq+0x35/0x50 [ 29.741743] do_IRQ+0x93/0x1d0 [ 29.745427] ret_from_intr+0x0/0x1e [ 29.749546] lock_acquire+0x1ec/0x3f0 [ 29.753839] _raw_spin_lock_bh+0x2f/0x40 [ 29.758393] batadv_nc_purge_paths+0xce/0x300 [ 29.763380] batadv_nc_worker+0x660/0xc50 [ 29.768021] process_one_work+0x793/0x14a0 [ 29.772749] worker_thread+0x5cc/0xff0 [ 29.777130] kthread+0x30d/0x420 [ 29.780991] ret_from_fork+0x24/0x30 [ 29.785193] [ 29.785193] other info that might help us debug this: [ 29.785193] [ 29.793306] Possible unsafe locking scenario: [ 29.793306] [ 29.799345] CPU0 CPU1 [ 29.803985] ---- ---- [ 29.808629] lock(&port_lock_key); [ 29.812227] lock(&(&gsm->tx_lock)->rlock); [ 29.819128] lock(&port_lock_key); [ 29.825242] lock(&(&gsm->tx_lock)->rlock); [ 29.829621] [ 29.829621] *** DEADLOCK *** [ 29.829621] [ 29.835649] 6 locks held by kworker/u4:4/2850: [ 29.840199] #0: ("%s""bat_events"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 [ 29.849276] #1: ((&(&bat_priv->nc.work)->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 [ 29.859478] #2: (key#14){+...}, at: [] batadv_nc_purge_paths+0xce/0x300 [ 29.867944] #3: (&(&i->lock)->rlock){-.-.}, at: [] serial8250_interrupt+0x3a/0x210 [ 29.877364] #4: (&port_lock_key){-.-.}, at: [] serial8250_handle_irq.part.0+0x20/0x330 [ 29.887168] #5: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref+0x1b/0x80 [ 29.895642] [ 29.895642] stack backtrace: [ 29.900123] CPU: 1 PID: 2850 Comm: kworker/u4:4 Not tainted 4.14.291-syzkaller #0 [ 29.907715] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 [ 29.917048] Workqueue: bat_events batadv_nc_worker [ 29.921948] Call Trace: [ 29.924502] [ 29.926639] dump_stack+0x1b2/0x281 [ 29.930240] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 29.936015] __lock_acquire+0x2e0e/0x3f20 [ 29.940140] ? trace_hardirqs_on+0x10/0x10 [ 29.944345] ? trace_hardirqs_on+0x10/0x10 [ 29.949255] ? trace_hardirqs_on+0x10/0x10 [ 29.954819] lock_acquire+0x170/0x3f0 [ 29.958592] ? gsmld_write_wakeup+0x4e/0xd0 [ 29.962885] ? lock_downgrade+0x740/0x740 [ 29.967007] _raw_spin_lock_irqsave+0x8c/0xc0 [ 29.971474] ? gsmld_write_wakeup+0x4e/0xd0 [ 29.975767] ? gsm_dlci_data_sweep+0x1b0/0x1b0 [ 29.980337] gsmld_write_wakeup+0x4e/0xd0 [ 29.984467] ? gsm_dlci_data_sweep+0x1b0/0x1b0 [ 29.989032] tty_wakeup+0xc3/0xf0 [ 29.992460] tty_port_default_wakeup+0x26/0x40 [ 29.997012] serial8250_tx_chars+0x3fe/0xc70 [ 30.001402] serial8250_handle_irq.part.0+0x28d/0x330 [ 30.006564] serial8250_default_handle_irq+0x8a/0x1f0 [ 30.011725] serial8250_interrupt+0xf3/0x210 [ 30.016109] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 30.021529] ? serial8250_backup_timeout+0x440/0x440 [ 30.026602] __handle_irq_event_percpu+0xee/0x7f0 [ 30.031416] handle_irq_event+0xed/0x240 [ 30.035450] ? handle_irq_event_percpu+0x110/0x110 [ 30.040439] handle_edge_irq+0x224/0xc40 [ 30.044472] handle_irq+0x35/0x50 [ 30.047904] do_IRQ+0x93/0x1d0 [ 30.051076] common_interrupt+0x93/0x93 [ 30.055021] [ 30.057230] RIP: 0010:lock_acquire+0x1ec/0x3f0 [ 30.061784] RSP: 0018:ffff8880ac7a7c00 EFLAGS: 00000286 ORIG_RAX: ffffffffffffffc8 [ 30.069476] RAX: 1ffffffff11e1341 RBX: ffff8880ac7985c0 RCX: 0000000000004292 [ 30.076731] RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000286 [ 30.083971] RBP: ffff8880960d9db0 R08: ffffffff8b9c2f90 R09: 0000000000040586 [ 30.091211] R10: ffff8880ac798e98 R11: ffff8880ac7985c0 R12: 0000000000000000 [ 30.098459] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 [ 30.105714] ? batadv_nc_path_search.constprop.0.isra.0+0x910/0x910 [ 30.112105] _raw_spin_lock_bh+0x2f/0x40 [ 30.116140] ? batadv_nc_purge_paths+0xce/0x300 [ 30.120797] batadv_nc_purge_paths+0xce/0x300 [ 30.125275] batadv_nc_worker+0x660/0xc50 [ 30.129414] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 30.134834] process_one_work+0x793/0x14a0 [ 30.139041] ? work_busy+0x320/0x320 [ 30.142725] ? worker_thread+0x158/0xff0 [ 30.146766] ? _raw_spin_unlock_irq+0x24/0x80 [ 30.151233] worker_thread+0x5cc/0xff0 [ 30.155196] ? rescuer_thread+0xc80/0xc80 [ 30.159316] kthread+0x30d/0x420 [ 30.162654] ? kthread_create_on_node+0xd0/0xd0 [ 30.167308] ret_from_fork+0x24/0x30 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program