[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 72.301233][ T27] audit: type=1800 audit(1583393656.905:25): pid=9769 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 72.321873][ T27] audit: type=1800 audit(1583393656.905:26): pid=9769 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 72.355086][ T27] audit: type=1800 audit(1583393656.905:27): pid=9769 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] 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 '10.128.0.14' (ECDSA) to the list of known hosts. syzkaller login: [ 82.807250][ T9925] IPVS: ftp: loaded support on port[0] = 21 [ 82.861927][ T9925] chnl_net:caif_netlink_parms(): no params data found [ 82.900774][ T9925] bridge0: port 1(bridge_slave_0) entered blocking state [ 82.908623][ T9925] bridge0: port 1(bridge_slave_0) entered disabled state [ 82.916647][ T9925] device bridge_slave_0 entered promiscuous mode [ 82.925156][ T9925] bridge0: port 2(bridge_slave_1) entered blocking state [ 82.932431][ T9925] bridge0: port 2(bridge_slave_1) entered disabled state [ 82.940371][ T9925] device bridge_slave_1 entered promiscuous mode [ 82.957804][ T9925] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 82.968631][ T9925] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 82.988780][ T9925] team0: Port device team_slave_0 added [ 82.996941][ T9925] team0: Port device team_slave_1 added [ 83.011815][ T9925] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 83.018959][ T9925] 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. [ 83.045734][ T9925] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 83.058836][ T9925] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 83.066417][ T9925] 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. [ 83.092440][ T9925] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 83.156798][ T9925] device hsr_slave_0 entered promiscuous mode [ 83.195115][ T9925] device hsr_slave_1 entered promiscuous mode [ 83.314889][ T9925] netdevsim netdevsim0 netdevsim0: renamed from eth0 [ 83.367955][ T9925] netdevsim netdevsim0 netdevsim1: renamed from eth1 [ 83.427633][ T9925] netdevsim netdevsim0 netdevsim2: renamed from eth2 [ 83.466936][ T9925] netdevsim netdevsim0 netdevsim3: renamed from eth3 [ 83.530402][ T9925] bridge0: port 2(bridge_slave_1) entered blocking state [ 83.537637][ T9925] bridge0: port 2(bridge_slave_1) entered forwarding state [ 83.545812][ T9925] bridge0: port 1(bridge_slave_0) entered blocking state [ 83.552890][ T9925] bridge0: port 1(bridge_slave_0) entered forwarding state [ 83.596779][ T9925] 8021q: adding VLAN 0 to HW filter on device bond0 [ 83.610583][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 83.621335][ T17] bridge0: port 1(bridge_slave_0) entered disabled state [ 83.629801][ T17] bridge0: port 2(bridge_slave_1) entered disabled state [ 83.638278][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 83.654682][ T9925] 8021q: adding VLAN 0 to HW filter on device team0 [ 83.666320][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 83.675743][ T5] bridge0: port 1(bridge_slave_0) entered blocking state [ 83.682935][ T5] bridge0: port 1(bridge_slave_0) entered forwarding state [ 83.699102][ T2693] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 83.708728][ T2693] bridge0: port 2(bridge_slave_1) entered blocking state [ 83.715825][ T2693] bridge0: port 2(bridge_slave_1) entered forwarding state [ 83.737951][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 83.746517][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 83.755383][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 83.763712][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 83.777208][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 83.788051][ T9925] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 83.807677][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready [ 83.815750][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready [ 83.830510][ T9925] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 83.849501][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 83.867942][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready [ 83.878332][ T2700] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 83.887944][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 83.895981][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 83.904738][ T9925] device veth0_vlan entered promiscuous mode [ 83.917268][ T9925] device veth1_vlan entered promiscuous mode [ 83.939459][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready [ 83.948264][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready [ 83.957262][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready [ 83.966581][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 83.977509][ T9925] device veth0_macvtap entered promiscuous mode [ 83.989581][ T9925] device veth1_macvtap entered promiscuous mode [ 84.006641][ T9925] batman_adv: batadv0: Interface activated: batadv_slave_0 [ 84.014120][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready [ 84.023751][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready [ 84.032048][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready [ 84.042616][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 84.054881][ T9925] batman_adv: batadv0: Interface activated: batadv_slave_1 [ 84.066622][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready [ 84.076058][ T2695] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready executing program executing program [ 84.982899][ C1] [ 84.985233][ C1] ============================================ [ 84.991459][ C1] WARNING: possible recursive locking detected [ 84.997592][ C1] 5.6.0-rc3-syzkaller #0 Not tainted [ 85.002998][ C1] -------------------------------------------- [ 85.009566][ C1] swapper/1/0 is trying to acquire lock: [ 85.015173][ C1] ffffffff8c352e10 (&port_lock_key){-.-.}, at: uart_write+0x1e1/0x6f0 [ 85.024989][ C1] [ 85.024989][ C1] but task is already holding lock: [ 85.032905][ C1] ffffffff8c352e10 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x2b0 [ 85.042532][ C1] [ 85.042532][ C1] other info that might help us debug this: [ 85.050620][ C1] Possible unsafe locking scenario: [ 85.050620][ C1] [ 85.058070][ C1] CPU0 [ 85.061333][ C1] ---- [ 85.064832][ C1] lock(&port_lock_key); [ 85.069177][ C1] lock(&port_lock_key); [ 85.073606][ C1] [ 85.073606][ C1] *** DEADLOCK *** [ 85.073606][ C1] [ 85.082313][ C1] May be due to missing lock nesting notation [ 85.082313][ C1] [ 85.092194][ C1] 3 locks held by swapper/1/0: [ 85.096974][ C1] #0: ffff88809f8998b0 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x2d/0x1a0 [ 85.106717][ C1] #1: ffffffff8c352e10 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x2b0 [ 85.116875][ C1] #2: ffff88809045e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 [ 85.125675][ C1] [ 85.125675][ C1] stack backtrace: [ 85.131634][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc3-syzkaller #0 [ 85.139943][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 85.150062][ C1] Call Trace: [ 85.153364][ C1] [ 85.156205][ C1] dump_stack+0x197/0x210 [ 85.160532][ C1] __lock_acquire.cold+0x15d/0x385 [ 85.165637][ C1] ? mark_held_locks+0xf0/0xf0 [ 85.170378][ C1] lock_acquire+0x190/0x410 [ 85.174877][ C1] ? uart_write+0x1e1/0x6f0 [ 85.179378][ C1] _raw_spin_lock_irqsave+0x95/0xcd [ 85.184643][ C1] ? uart_write+0x1e1/0x6f0 [ 85.189129][ C1] uart_write+0x1e1/0x6f0 [ 85.193438][ C1] ? trace_hardirqs_off+0x62/0x240 [ 85.198525][ C1] ? uart_wait_until_sent+0x690/0x690 [ 85.203890][ C1] ? _raw_spin_unlock_irqrestore+0x9f/0xe0 [ 85.209683][ C1] ? n_hdlc_buf_get+0x1b6/0x260 [ 85.215393][ C1] ? uart_wait_until_sent+0x690/0x690 [ 85.220752][ C1] n_hdlc_send_frames+0x29a/0x480 [ 85.225768][ C1] n_hdlc_tty_wakeup+0xc0/0xe0 [ 85.230521][ C1] ? n_hdlc_tty_write+0x6e0/0x6e0 [ 85.235537][ C1] tty_wakeup+0xe9/0x120 [ 85.239773][ C1] tty_port_default_wakeup+0x2b/0x40 [ 85.245050][ C1] tty_port_tty_wakeup+0x57/0x70 [ 85.249991][ C1] uart_write_wakeup+0x46/0x70 [ 85.254754][ C1] serial8250_tx_chars+0x495/0xaf0 [ 85.259952][ C1] serial8250_handle_irq.part.0+0x261/0x2b0 [ 85.265823][ C1] serial8250_default_handle_irq+0xc0/0x150 [ 85.271692][ C1] serial8250_interrupt+0xf1/0x1a0 [ 85.276794][ C1] ? uart_proc_show.cold+0x2e/0x2e [ 85.281895][ C1] __handle_irq_event_percpu+0x15d/0x970 [ 85.287505][ C1] handle_irq_event_percpu+0x74/0x160 [ 85.292854][ C1] ? do_raw_spin_lock+0x139/0x2f0 [ 85.297870][ C1] ? __handle_irq_event_percpu+0x970/0x970 [ 85.303675][ C1] ? do_raw_spin_unlock+0x181/0x270 [ 85.309390][ C1] handle_irq_event+0xa7/0x134 [ 85.314138][ C1] handle_edge_irq+0x25e/0x8d0 [ 85.318980][ C1] ? rcu_dynticks_curr_cpu_in_eqs+0x54/0xb0 [ 85.325117][ C1] do_IRQ+0xde/0x280 [ 85.328994][ C1] common_interrupt+0xf/0xf [ 85.333647][ C1] [ 85.336584][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 85.341950][ C1] Code: c8 c3 c3 f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 94 05 58 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 84 05 58 00 fb f4 cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 5e 83 72 f9 e8 c9 [ 85.361560][ C1] RSP: 0018:ffffc90000d3fd68 EFLAGS: 00000286 ORIG_RAX: ffffffffffffffd7 [ 85.370007][ C1] RAX: 1ffffffff136763a RBX: ffff8880a99fc340 RCX: 0000000000000000 [ 85.378232][ C1] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a99fcbd4 [ 85.386225][ C1] RBP: ffffc90000d3fd98 R08: ffff8880a99fc340 R09: 0000000000000000 [ 85.394178][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 [ 85.402153][ C1] R13: ffffffff8aa5b4c0 R14: 0000000000000000 R15: 0000000000000001 [ 85.410143][ C1] ? default_idle+0x4e/0x360 [ 85.414732][ C1] arch_cpu_idle+0xa/0x10 [ 85.419112][ C1] default_idle_call+0x84/0xb0 [ 85.423915][ C1] do_idle+0x3c8/0x6e0 [ 85.427985][ C1] ? arch_cpu_idle_exit+0x80/0x80 [ 85.432992][ C1] cpu_startup_entry+0x1b/0x20 [ 85.437744][ C1] start_secondary+0x2f4/0x410 [ 85.442702][ C1] ? set_cpu_sibling_map+0x2140/0x2140 [ 85.448149][ C1] secondary_startup_64+0xa4/0xb0