[ OK ] Started OpenBSD Secure Shell server. [ 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 '10.128.0.95' (ECDSA) to the list of known hosts. syzkaller login: [ 46.922000][ T8360] IPVS: ftp: loaded support on port[0] = 21 [ 47.007544][ T8360] chnl_net:caif_netlink_parms(): no params data found [ 47.055724][ T8360] bridge0: port 1(bridge_slave_0) entered blocking state [ 47.064409][ T8360] bridge0: port 1(bridge_slave_0) entered disabled state [ 47.073284][ T8360] device bridge_slave_0 entered promiscuous mode [ 47.083388][ T8360] bridge0: port 2(bridge_slave_1) entered blocking state [ 47.090747][ T8360] bridge0: port 2(bridge_slave_1) entered disabled state [ 47.098819][ T8360] device bridge_slave_1 entered promiscuous mode [ 47.116711][ T8360] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 47.127985][ T8360] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 47.149627][ T8360] team0: Port device team_slave_0 added [ 47.156568][ T8360] team0: Port device team_slave_1 added [ 47.174321][ T8360] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 47.181557][ T8360] 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. [ 47.209361][ T8360] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 47.222162][ T8360] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 47.229181][ T8360] 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. [ 47.255754][ T8360] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 47.280527][ T8360] device hsr_slave_0 entered promiscuous mode [ 47.287049][ T8360] device hsr_slave_1 entered promiscuous mode [ 47.373093][ T8360] netdevsim netdevsim0 netdevsim0: renamed from eth0 [ 47.384174][ T8360] netdevsim netdevsim0 netdevsim1: renamed from eth1 [ 47.395854][ T8360] netdevsim netdevsim0 netdevsim2: renamed from eth2 [ 47.405204][ T8360] netdevsim netdevsim0 netdevsim3: renamed from eth3 [ 47.427772][ T8360] bridge0: port 2(bridge_slave_1) entered blocking state [ 47.434970][ T8360] bridge0: port 2(bridge_slave_1) entered forwarding state [ 47.442910][ T8360] bridge0: port 1(bridge_slave_0) entered blocking state [ 47.450093][ T8360] bridge0: port 1(bridge_slave_0) entered forwarding state [ 47.487877][ T8360] 8021q: adding VLAN 0 to HW filter on device bond0 [ 47.500791][ T3138] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 47.512268][ T3138] bridge0: port 1(bridge_slave_0) entered disabled state [ 47.520533][ T3138] bridge0: port 2(bridge_slave_1) entered disabled state [ 47.531010][ T3138] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 47.543191][ T8360] 8021q: adding VLAN 0 to HW filter on device team0 [ 47.555085][ T3138] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 47.564759][ T3138] bridge0: port 1(bridge_slave_0) entered blocking state [ 47.571871][ T3138] bridge0: port 1(bridge_slave_0) entered forwarding state [ 47.588396][ T36] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 47.596685][ T36] bridge0: port 2(bridge_slave_1) entered blocking state [ 47.603803][ T36] bridge0: port 2(bridge_slave_1) entered forwarding state [ 47.617023][ T8] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 47.626274][ T8] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 47.640197][ T8] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 47.655910][ T8360] hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network [ 47.668872][ T8360] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network [ 47.681206][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 47.690655][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 47.700696][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 47.716236][ T36] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready [ 47.723753][ T36] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready [ 47.737280][ T8360] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 47.755580][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 47.774897][ T8360] device veth0_vlan entered promiscuous mode [ 47.783319][ T20] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 47.791704][ T20] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 47.799829][ T20] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 47.812228][ T8360] device veth1_vlan entered promiscuous mode [ 47.832572][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready [ 47.840994][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready [ 47.849908][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 47.861623][ T8360] device veth0_macvtap entered promiscuous mode [ 47.870983][ T8360] device veth1_macvtap entered promiscuous mode [ 47.887471][ T8360] batman_adv: batadv0: Interface activated: batadv_slave_0 [ 47.897004][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 47.907533][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready [ 47.921548][ T8360] batman_adv: batadv0: Interface activated: batadv_slave_1 [ 47.929212][ T7] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready [ 47.941320][ T8360] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0 executing program [ 47.951256][ T8360] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0 [ 47.960960][ T8360] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0 [ 47.969925][ T8360] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0 [ 48.011104][ T8360] ttyprintk ttyprintk: tty_port_close_start: tty->count = 1 port count = 2 [ 48.020292][ C0] [ 48.020298][ C0] ====================================================== [ 48.020301][ C0] WARNING: possible circular locking dependency detected [ 48.020304][ C0] 5.12.0-rc5-syzkaller #0 Not tainted [ 48.020306][ C0] ------------------------------------------------------ [ 48.020309][ C0] syz-executor614/8360 is trying to acquire lock: [ 48.020311][ C0] ffffffff8c704c60 (console_owner){....}-{0:0}, at: console_lock_spinning_enable+0x2d/0x60 [ 48.020323][ C0] [ 48.020325][ C0] but task is already holding lock: [ 48.020327][ C0] ffffffff90341918 (&port->lock){-.-.}-{2:2}, at: tty_port_close_start+0x58/0x550 [ 48.020335][ C0] [ 48.020337][ C0] which lock already depends on the new lock. [ 48.020339][ C0] [ 48.020340][ C0] [ 48.020342][ C0] the existing dependency chain (in reverse order) is: [ 48.020344][ C0] [ 48.020345][ C0] -> #2 (&port->lock){-.-.}-{2:2}: [ 48.020353][ C0] lock_acquire+0x126/0x650 [ 48.020355][ C0] _raw_spin_lock_irqsave+0x73/0xa0 [ 48.020357][ C0] tty_port_tty_get+0x21/0xe0 [ 48.020359][ C0] tty_port_default_wakeup+0x11/0x40 [ 48.020361][ C0] serial8250_tx_chars+0x5ea/0x800 [ 48.020363][ C0] serial8250_handle_irq+0x2fd/0x3e0 [ 48.020365][ C0] serial8250_default_handle_irq+0xaf/0x190 [ 48.020368][ C0] serial8250_interrupt+0xa3/0x1e0 [ 48.020370][ C0] __handle_irq_event_percpu+0x1b7/0x620 [ 48.020372][ C0] handle_irq_event+0xbd/0x280 [ 48.020374][ C0] handle_edge_irq+0x245/0xbe0 [ 48.020376][ C0] __common_interrupt+0xce/0x1e0 [ 48.020378][ C0] common_interrupt+0x9c/0xc0 [ 48.020380][ C0] asm_common_interrupt+0x1e/0x40 [ 48.020382][ C0] _raw_spin_unlock_irqrestore+0x7a/0xc0 [ 48.020384][ C0] uart_write+0x6a1/0x8f0 [ 48.020386][ C0] do_output_char+0x638/0x940 [ 48.020388][ C0] n_tty_write+0xd5c/0x1180 [ 48.020390][ C0] file_tty_write+0x5c5/0x9a0 [ 48.020393][ C0] do_iter_readv_writev+0x48c/0x650 [ 48.020396][ C0] do_iter_write+0x16c/0x5f0 [ 48.020398][ C0] do_writev+0x19a/0x350 [ 48.020400][ C0] do_syscall_64+0x2d/0x70 [ 48.020402][ C0] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 48.020404][ C0] [ 48.020405][ C0] -> #1 (&port_lock_key){-.-.}-{2:2}: [ 48.020413][ C0] lock_acquire+0x126/0x650 [ 48.020415][ C0] _raw_spin_lock_irqsave+0x73/0xa0 [ 48.020417][ C0] serial8250_console_write+0x107/0xd20 [ 48.020419][ C0] console_unlock+0x930/0xe00 [ 48.020421][ C0] vprintk_emit+0x1ab/0x270 [ 48.020423][ C0] printk+0x62/0x83 [ 48.020425][ C0] register_console+0x802/0xad0 [ 48.020427][ C0] univ8250_console_init+0x41/0x43 [ 48.020429][ C0] console_init+0x52/0x97 [ 48.020431][ C0] start_kernel+0x30c/0x544 [ 48.020433][ C0] secondary_startup_64_no_verify+0xb0/0xbb [ 48.020435][ C0] [ 48.020436][ C0] -> #0 (console_owner){....}-{0:0}: [ 48.020444][ C0] check_prevs_add+0x339/0x5c20 [ 48.020446][ C0] __lock_acquire+0x41f7/0x5e60 [ 48.020448][ C0] lock_acquire+0x126/0x650 [ 48.020450][ C0] console_lock_spinning_enable+0x52/0x60 [ 48.020452][ C0] console_unlock+0x66e/0xe00 [ 48.020454][ C0] vprintk_emit+0x1ab/0x270 [ 48.020456][ C0] printk+0x62/0x83 [ 48.020458][ C0] tty_port_close_start+0x3c8/0x550 [ 48.020460][ C0] tty_port_close+0x26/0x140 [ 48.020462][ C0] tty_release+0x30c/0xef0 [ 48.020464][ C0] __fput+0x352/0x7b0 [ 48.020465][ C0] task_work_run+0x146/0x1c0 [ 48.020468][ C0] exit_to_user_mode_prepare+0x10b/0x1e0 [ 48.020470][ C0] syscall_exit_to_user_mode+0x26/0x70 [ 48.020472][ C0] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 48.020474][ C0] [ 48.020475][ C0] other info that might help us debug this: [ 48.020477][ C0] [ 48.020478][ C0] Chain exists of: [ 48.020480][ C0] console_owner --> &port_lock_key --> &port->lock [ 48.020491][ C0] [ 48.020492][ C0] Possible unsafe locking scenario: [ 48.020494][ C0] [ 48.020495][ C0] CPU0 CPU1 [ 48.020497][ C0] ---- ---- [ 48.020499][ C0] lock(&port->lock); [ 48.020504][ C0] lock(&port_lock_key); [ 48.020509][ C0] lock(&port->lock); [ 48.020515][ C0] lock(console_owner); [ 48.020520][ C0] [ 48.020522][ C0] *** DEADLOCK *** [ 48.020523][ C0] [ 48.020525][ C0] 3 locks held by syz-executor614/8360: [ 48.020526][ C0] #0: ffff88802c01e1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_release+0xac/0xef0 [ 48.020536][ C0] #1: ffffffff90341918 (&port->lock){-.-.}-{2:2}, at: tty_port_close_start+0x58/0x550 [ 48.020547][ C0] #2: ffffffff8c5ec980 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0x192/0x270 [ 48.020556][ C0] [ 48.020558][ C0] stack backtrace: [ 48.020560][ C0] CPU: 0 PID: 8360 Comm: syz-executor614 Not tainted 5.12.0-rc5-syzkaller #0 [ 48.020563][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.020566][ C0] Call Trace: [ 48.020567][ C0] dump_stack+0x176/0x24e [ 48.020569][ C0] print_circular_bug+0xadf/0xd80 [ 48.020571][ C0] ? stack_trace_save+0xad/0x150 [ 48.020573][ C0] ? save_trace+0x5a/0x9f0 [ 48.020575][ C0] check_noncircular+0x221/0x2d0 [ 48.020577][ C0] ? add_lock_to_list+0x1c7/0x2d0 [ 48.020578][ C0] check_prevs_add+0x339/0x5c20 [ 48.020580][ C0] ? mark_lock+0x13a/0x1fe0 [ 48.020582][ C0] ? mark_lock+0x13a/0x1fe0 [ 48.020584][ C0] ? put_dec_trunc8+0x18a/0x390 [ 48.020586][ C0] ? put_dec+0xb9/0xe0 [ 48.020587][ C0] __lock_acquire+0x41f7/0x5e60 [ 48.020589][ C0] lock_acquire+0x126/0x650 [ 48.020591][ C0] ? console_lock_spinning_enable+0x2d/0x60 [ 48.020593][ C0] ? console_lock_spinning_enable+0x2d/0x60 [ 48.020595][ C0] console_lock_spinning_enable+0x52/0x60 [ 48.020597][ C0] ? console_lock_spinning_enable+0x2d/0x60 [ 48.020600][ C0] console_unlock+0x66e/0xe00 [ 48.020601][ C0] vprintk_emit+0x1ab/0x270 [ 48.020603][ C0] printk+0x62/0x83 [ 48.020605][ C0] tty_port_close_start+0x3c8/0x550 [ 48.020607][ C0] ? tpk_open+0x60/0x60 [ 48.020608][ C0] tty_port_close+0x26/0x140 [ 48.020610][ C0] ? tpk_open+0x60/0x60 [ 48.020612][ C0] tty_release+0x30c/0xef0 [ 48.020614][ C0] ? __fsnotify_parent+0x44e/0x620 [ 48.020616][ C0] ? ima_file_free+0xe8/0x3b0 [ 48.020618][ C0] ? tty_release_struct+0xd0/0xd0 [ 48.020619][ C0] __fput+0x352/0x7b0 [ 48.020621][ C0] task_work_run+0x146/0x1c0 [ 48.020623][ C0] exit_to_user_mode_prepare+0x10b/0x1e0 [ 48.020625][ C0] ? trace_irq_disable_rcuidle+0x11/0x170 [ 48.020627][ C0] syscall_exit_to_user_mode+0x26/0x70 [ 48.020629][ C0] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 48.020631][ C0] RIP: 0033:0x40968b [ 48.020634][ C0] Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 03 fd ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 41 f