Warning: Permanently added '10.128.0.46' (ECDSA) to the list of known hosts. executing program [ 61.896867][ T7011] nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead. [ 61.999518][ C0] [ 62.001942][ C0] ======================================================== [ 62.009198][ C0] WARNING: possible irq lock inversion dependency detected [ 62.016569][ C0] 5.6.0-syzkaller #0 Not tainted [ 62.021513][ C0] -------------------------------------------------------- [ 62.029634][ C0] ksoftirqd/0/9 just changed the state of lock: [ 62.037100][ C0] ffffffff898090d8 (tasklist_lock){.+.?}-{2:2}, at: send_sigurg+0x9f/0x320 [ 62.045803][ C0] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 62.054728][ C0] (&pid->wait_pidfd){+.+.}-{2:2} [ 62.054737][ C0] [ 62.054737][ C0] [ 62.054737][ C0] and interrupts could create inverse lock ordering between them. [ 62.054737][ C0] [ 62.075141][ C0] [ 62.075141][ C0] other info that might help us debug this: [ 62.083289][ C0] Possible interrupt unsafe locking scenario: [ 62.083289][ C0] [ 62.092553][ C0] CPU0 CPU1 [ 62.098169][ C0] ---- ---- [ 62.103558][ C0] lock(&pid->wait_pidfd); [ 62.108068][ C0] local_irq_disable(); [ 62.114995][ C0] lock(tasklist_lock); [ 62.121734][ C0] lock(&pid->wait_pidfd); [ 62.129167][ C0] [ 62.132628][ C0] lock(tasklist_lock); [ 62.137017][ C0] [ 62.137017][ C0] *** DEADLOCK *** [ 62.137017][ C0] [ 62.145409][ C0] 4 locks held by ksoftirqd/0/9: [ 62.150319][ C0] #0: ffffffff899bbbc0 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x1ad/0x7a0 [ 62.159780][ C0] #1: ffffffff899bbbc0 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x124/0x360 [ 62.171837][ C0] #2: ffff8880a1d1e120 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x2d09/0x39c0 [ 62.181201][ C0] #3: ffff8880949e6478 (&f->f_owner.lock){.+.?}-{2:2}, at: send_sigurg+0x1a/0x320 [ 62.190513][ C0] [ 62.190513][ C0] the shortest dependencies between 2nd lock and 1st lock: [ 62.200164][ C0] -> (&pid->wait_pidfd){+.+.}-{2:2} { [ 62.205705][ C0] HARDIRQ-ON-W at: [ 62.209770][ C0] lock_acquire+0x1f2/0x8f0 [ 62.216177][ C0] _raw_spin_lock+0x2a/0x40 [ 62.222516][ C0] proc_pid_make_inode+0x1f9/0x3c0 [ 62.230038][ C0] proc_pid_instantiate+0x51/0x150 [ 62.237039][ C0] proc_pid_lookup+0x1da/0x340 [ 62.243597][ C0] proc_root_lookup+0x20/0x60 [ 62.250191][ C0] __lookup_slow+0x256/0x490 [ 62.256681][ C0] walk_component+0x418/0x6a0 [ 62.263574][ C0] link_path_walk.part.0+0x4f1/0xb50 [ 62.270720][ C0] path_openat+0x25a/0x27d0 [ 62.277047][ C0] do_filp_open+0x192/0x260 [ 62.283483][ C0] do_sys_openat2+0x585/0x7d0 [ 62.290062][ C0] do_sys_open+0xc3/0x140 [ 62.296200][ C0] do_syscall_64+0xf6/0x7d0 [ 62.302622][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 62.310419][ C0] SOFTIRQ-ON-W at: [ 62.315169][ C0] lock_acquire+0x1f2/0x8f0 [ 62.321748][ C0] _raw_spin_lock+0x2a/0x40 [ 62.328425][ C0] proc_pid_make_inode+0x1f9/0x3c0 [ 62.335598][ C0] proc_pid_instantiate+0x51/0x150 [ 62.344541][ C0] proc_pid_lookup+0x1da/0x340 [ 62.351373][ C0] proc_root_lookup+0x20/0x60 [ 62.358038][ C0] __lookup_slow+0x256/0x490 [ 62.364616][ C0] walk_component+0x418/0x6a0 [ 62.371302][ C0] link_path_walk.part.0+0x4f1/0xb50 [ 62.379534][ C0] path_openat+0x25a/0x27d0 [ 62.385845][ C0] do_filp_open+0x192/0x260 [ 62.392186][ C0] do_sys_openat2+0x585/0x7d0 [ 62.398779][ C0] do_sys_open+0xc3/0x140 [ 62.405009][ C0] do_syscall_64+0xf6/0x7d0 [ 62.411328][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 62.419214][ C0] INITIAL USE at: [ 62.423196][ C0] lock_acquire+0x1f2/0x8f0 [ 62.429434][ C0] _raw_spin_lock_irqsave+0x8c/0xbf [ 62.436431][ C0] __wake_up_common_lock+0xb4/0x130 [ 62.443343][ C0] do_notify_parent+0x19e/0xe60 [ 62.449923][ C0] do_exit+0x238f/0x2dd0 [ 62.455905][ C0] call_usermodehelper_exec_async+0x507/0x710 [ 62.463685][ C0] ret_from_fork+0x24/0x30 [ 62.469808][ C0] } [ 62.472376][ C0] ... key at: [] __key.53827+0x0/0x40 [ 62.479905][ C0] ... acquired at: [ 62.483780][ C0] _raw_spin_lock_irqsave+0x8c/0xbf [ 62.489129][ C0] __wake_up_common_lock+0xb4/0x130 [ 62.494496][ C0] do_notify_parent+0x19e/0xe60 [ 62.499622][ C0] do_exit+0x238f/0x2dd0 [ 62.504012][ C0] call_usermodehelper_exec_async+0x507/0x710 [ 62.510226][ C0] ret_from_fork+0x24/0x30 [ 62.514785][ C0] [ 62.517087][ C0] -> (tasklist_lock){.+.?}-{2:2} { [ 62.522190][ C0] HARDIRQ-ON-R at: [ 62.526494][ C0] lock_acquire+0x1f2/0x8f0 [ 62.532896][ C0] _raw_read_lock+0x2d/0x40 [ 62.539109][ C0] do_wait+0x3b9/0xa00 [ 62.544798][ C0] kernel_wait4+0x14c/0x260 [ 62.551279][ C0] call_usermodehelper_exec_work+0x172/0x260 [ 62.559258][ C0] process_one_work+0x965/0x16a0 [ 62.566140][ C0] worker_thread+0x96/0xe20 [ 62.572469][ C0] kthread+0x388/0x470 [ 62.578168][ C0] ret_from_fork+0x24/0x30 [ 62.584207][ C0] IN-SOFTIRQ-R at: [ 62.588434][ C0] lock_acquire+0x1f2/0x8f0 [ 62.594574][ C0] _raw_read_lock+0x2d/0x40 [ 62.600720][ C0] send_sigurg+0x9f/0x320 [ 62.606675][ C0] sk_send_sigurg+0x76/0x300 [ 62.612896][ C0] tcp_urg+0x38c/0xb80 [ 62.618700][ C0] tcp_rcv_established+0x8f3/0x1d90 [ 62.625736][ C0] tcp_v4_do_rcv+0x605/0x8b0 [ 62.632318][ C0] tcp_v4_rcv+0x2f60/0x39c0 [ 62.638812][ C0] ip_protocol_deliver_rcu+0x57/0x880 [ 62.647038][ C0] ip_local_deliver_finish+0x220/0x360 [ 62.656052][ C0] ip_local_deliver+0x1c8/0x4e0 [ 62.662632][ C0] ip_rcv_finish+0x1da/0x2f0 [ 62.669326][ C0] ip_rcv+0xd0/0x3c0 [ 62.675018][ C0] __netif_receive_skb_one_core+0xf5/0x160 [ 62.682469][ C0] __netif_receive_skb+0x27/0x1c0 [ 62.689253][ C0] process_backlog+0x21e/0x7a0 [ 62.695661][ C0] net_rx_action+0x4c2/0x1070 [ 62.702127][ C0] __do_softirq+0x26c/0x9f7 [ 62.708626][ C0] run_ksoftirqd+0x89/0x100 [ 62.715202][ C0] smpboot_thread_fn+0x653/0x9e0 [ 62.721928][ C0] kthread+0x388/0x470 [ 62.727960][ C0] ret_from_fork+0x24/0x30 [ 62.734261][ C0] SOFTIRQ-ON-R at: [ 62.739613][ C0] lock_acquire+0x1f2/0x8f0 [ 62.745960][ C0] _raw_read_lock+0x2d/0x40 [ 62.753772][ C0] do_wait+0x3b9/0xa00 [ 62.760382][ C0] kernel_wait4+0x14c/0x260 [ 62.766546][ C0] call_usermodehelper_exec_work+0x172/0x260 [ 62.774340][ C0] process_one_work+0x965/0x16a0 [ 62.781530][ C0] worker_thread+0x96/0xe20 [ 62.787674][ C0] kthread+0x388/0x470 [ 62.793489][ C0] ret_from_fork+0x24/0x30 [ 62.799579][ C0] INITIAL USE at: [ 62.803901][ C0] lock_acquire+0x1f2/0x8f0 [ 62.810006][ C0] _raw_write_lock_irq+0x5b/0x80 [ 62.816497][ C0] copy_process+0x3322/0x7110 [ 62.822736][ C0] _do_fork+0x12d/0x1010 [ 62.828693][ C0] kernel_thread+0xb8/0xf0 [ 62.834670][ C0] rest_init+0x23/0x365 [ 62.840585][ C0] start_kernel+0x867/0x8a1 [ 62.846641][ C0] secondary_startup_64+0xa4/0xb0 [ 62.853421][ C0] } [ 62.855998][ C0] ... key at: [] tasklist_lock+0x18/0x40 [ 62.863690][ C0] ... acquired at: [ 62.868012][ C0] mark_lock+0x624/0xf10 [ 62.872410][ C0] __lock_acquire+0x1ed9/0x4e00 [ 62.877481][ C0] lock_acquire+0x1f2/0x8f0 [ 62.882486][ C0] _raw_read_lock+0x2d/0x40 [ 62.887147][ C0] send_sigurg+0x9f/0x320 [ 62.891665][ C0] sk_send_sigurg+0x76/0x300 [ 62.896539][ C0] tcp_urg+0x38c/0xb80 [ 62.900931][ C0] tcp_rcv_established+0x8f3/0x1d90 [ 62.906294][ C0] tcp_v4_do_rcv+0x605/0x8b0 [ 62.911236][ C0] tcp_v4_rcv+0x2f60/0x39c0 [ 62.915893][ C0] ip_protocol_deliver_rcu+0x57/0x880 [ 62.922209][ C0] ip_local_deliver_finish+0x220/0x360 [ 62.927839][ C0] ip_local_deliver+0x1c8/0x4e0 [ 62.933438][ C0] ip_rcv_finish+0x1da/0x2f0 [ 62.938186][ C0] ip_rcv+0xd0/0x3c0 [ 62.942392][ C0] __netif_receive_skb_one_core+0xf5/0x160 [ 62.948458][ C0] __netif_receive_skb+0x27/0x1c0 [ 62.953639][ C0] process_backlog+0x21e/0x7a0 [ 62.958556][ C0] net_rx_action+0x4c2/0x1070 [ 62.963464][ C0] __do_softirq+0x26c/0x9f7 [ 62.968262][ C0] run_ksoftirqd+0x89/0x100 [ 62.973060][ C0] smpboot_thread_fn+0x653/0x9e0 [ 62.978159][ C0] kthread+0x388/0x470 [ 62.982377][ C0] ret_from_fork+0x24/0x30 [ 62.986938][ C0] [ 62.989241][ C0] [ 62.989241][ C0] stack backtrace: [ 62.995119][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.6.0-syzkaller #0 [ 63.002808][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.012976][ C0] Call Trace: [ 63.016317][ C0] dump_stack+0x188/0x20d [ 63.020654][ C0] check_usage_forwards.cold+0x20/0x29 [ 63.026230][ C0] ? check_usage_backwards+0x4e0/0x4e0 [ 63.031676][ C0] ? stack_trace_save+0x8c/0xc0 [ 63.036506][ C0] ? stack_trace_consume_entry+0x160/0x160 [ 63.042447][ C0] ? __bfs+0x76/0x520 [ 63.046407][ C0] ? save_trace+0x42/0x9f0 [ 63.050802][ C0] mark_lock+0x624/0xf10 [ 63.055039][ C0] ? check_usage_backwards+0x4e0/0x4e0 [ 63.060484][ C0] ? print_usage_bug+0x240/0x240 [ 63.065413][ C0] __lock_acquire+0x1ed9/0x4e00 [ 63.070253][ C0] ? mark_held_locks+0xe0/0xe0 [ 63.075010][ C0] ? bictcp_cong_avoid+0x142/0xe80 [ 63.080109][ C0] ? tcp_rate_gen+0x456/0x6a0 [ 63.084802][ C0] ? tcp_newly_delivered+0x116/0x160 [ 63.090088][ C0] ? tcp_update_pacing_rate+0x1cf/0x2d0 [ 63.095742][ C0] lock_acquire+0x1f2/0x8f0 [ 63.100228][ C0] ? send_sigurg+0x9f/0x320 [ 63.104716][ C0] ? lock_release+0x800/0x800 [ 63.109381][ C0] _raw_read_lock+0x2d/0x40 [ 63.113873][ C0] ? send_sigurg+0x9f/0x320 [ 63.118367][ C0] send_sigurg+0x9f/0x320 [ 63.122680][ C0] sk_send_sigurg+0x76/0x300 [ 63.127246][ C0] tcp_urg+0x38c/0xb80 [ 63.131294][ C0] ? __tcp_ack_snd_check+0x950/0x950 [ 63.136570][ C0] ? tcp_validate_incoming+0x42b/0x1670 [ 63.142086][ C0] tcp_rcv_established+0x8f3/0x1d90 [ 63.147260][ C0] ? lock_release+0x800/0x800 [ 63.151909][ C0] ? tcp_data_queue+0x4430/0x4430 [ 63.156916][ C0] ? do_raw_spin_lock+0x129/0x2e0 [ 63.161916][ C0] tcp_v4_do_rcv+0x605/0x8b0 [ 63.166479][ C0] tcp_v4_rcv+0x2f60/0x39c0 [ 63.170974][ C0] ? tcp_v4_early_demux+0x8d0/0x8d0 [ 63.176168][ C0] ? rcu_read_lock_held+0x9c/0xb0 [ 63.181181][ C0] ? rcu_read_lock_held_common+0x130/0x130 [ 63.186976][ C0] ip_protocol_deliver_rcu+0x57/0x880 [ 63.192327][ C0] ip_local_deliver_finish+0x220/0x360 [ 63.197775][ C0] ip_local_deliver+0x1c8/0x4e0 [ 63.202602][ C0] ? ip_local_deliver_finish+0x360/0x360 [ 63.208208][ C0] ? ip_rcv+0x24e/0x3c0 [ 63.212341][ C0] ? ip_protocol_deliver_rcu+0x880/0x880 [ 63.217957][ C0] ? lock_downgrade+0x840/0x840 [ 63.222778][ C0] ? ip_rcv_finish_core.isra.0+0x606/0x1ec0 [ 63.228653][ C0] ip_rcv_finish+0x1da/0x2f0 [ 63.233219][ C0] ip_rcv+0xd0/0x3c0 [ 63.237085][ C0] ? ip_local_deliver+0x4e0/0x4e0 [ 63.242101][ C0] ? ip_rcv_finish_core.isra.0+0x1ec0/0x1ec0 [ 63.249881][ C0] ? lock_acquire+0x1f2/0x8f0 [ 63.254628][ C0] ? process_backlog+0x1ad/0x7a0 [ 63.259576][ C0] ? ip_local_deliver+0x4e0/0x4e0 [ 63.264882][ C0] __netif_receive_skb_one_core+0xf5/0x160 [ 63.270684][ C0] ? __netif_receive_skb_core+0x30e0/0x30e0 [ 63.276559][ C0] ? rwlock_bug.part.0+0x90/0x90 [ 63.281783][ C0] __netif_receive_skb+0x27/0x1c0 [ 63.286791][ C0] process_backlog+0x21e/0x7a0 [ 63.291552][ C0] ? net_rx_action+0x25f/0x1070 [ 63.296383][ C0] net_rx_action+0x4c2/0x1070 [ 63.301041][ C0] ? napi_busy_loop+0x950/0x950 [ 63.305877][ C0] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.312066][ C0] __do_softirq+0x26c/0x9f7 [ 63.316564][ C0] ? takeover_tasklets+0x810/0x810 [ 63.321872][ C0] run_ksoftirqd+0x89/0x100 [ 63.326382][ C0] smpboot_thread_fn+0x653/0x9e0 [ 63.332178][ C0] ? __smpboot_create_thread.part.0+0x340/0x340 [ 63.338497][ C0] ? __kthread_parkme+0x13f/0x1e0 [ 63.343533][ C0] ? __smpboot_create_thread.part.0+0x340/0x340 [ 63.349765][ C0] kthread+0x388/0x470 [ 63.353820][ C0] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.359521][ C0] ret_from_fork+0x24/0x30