Warning: Permanently added '10.128.0.19' (ECDSA) to the list of known hosts. executing program [ 60.910264][ C1] [ 60.912721][ C1] ======================================================== [ 60.919897][ C1] WARNING: possible irq lock inversion dependency detected [ 60.927114][ C1] 5.6.0-syzkaller #0 Not tainted [ 60.932043][ C1] -------------------------------------------------------- [ 60.939825][ C1] swapper/1/0 just changed the state of lock: [ 60.945896][ C1] ffff8880920d5cd8 (&ctx->ctx_lock){..-.}-{2:2}, at: free_ioctx_users+0x2b/0x450 [ 60.954994][ C1] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 60.963045][ C1] (&pid->wait_pidfd){+.+.}-{2:2} [ 60.963054][ C1] [ 60.963054][ C1] [ 60.963054][ C1] and interrupts could create inverse lock ordering between them. [ 60.963054][ C1] [ 60.982474][ C1] [ 60.982474][ C1] other info that might help us debug this: [ 60.990524][ C1] Possible interrupt unsafe locking scenario: [ 60.990524][ C1] [ 60.998838][ C1] CPU0 CPU1 [ 61.004188][ C1] ---- ---- [ 61.009532][ C1] lock(&pid->wait_pidfd); [ 61.014109][ C1] local_irq_disable(); [ 61.021103][ C1] lock(&ctx->ctx_lock); [ 61.028123][ C1] lock(&pid->wait_pidfd); [ 61.035120][ C1] [ 61.038552][ C1] lock(&ctx->ctx_lock); [ 61.043034][ C1] [ 61.043034][ C1] *** DEADLOCK *** [ 61.043034][ C1] [ 61.051157][ C1] 2 locks held by swapper/1/0: [ 61.055889][ C1] #0: ffffffff899bbaa0 (rcu_callback){....}-{0:0}, at: rcu_core+0x520/0x1370 [ 61.064732][ C1] #1: ffffffff899bbbc0 (rcu_read_lock){....}-{1:2}, at: percpu_ref_switch_to_atomic_rcu+0x209/0x540 [ 61.075567][ C1] [ 61.075567][ C1] the shortest dependencies between 2nd lock and 1st lock: [ 61.085098][ C1] -> (&pid->wait_pidfd){+.+.}-{2:2} { [ 61.090537][ C1] HARDIRQ-ON-W at: [ 61.094748][ C1] lock_acquire+0x1f2/0x8f0 [ 61.101062][ C1] _raw_spin_lock+0x2a/0x40 [ 61.107502][ C1] proc_pid_make_inode+0x1f9/0x3c0 [ 61.114429][ C1] proc_pid_instantiate+0x51/0x150 [ 61.121348][ C1] proc_pid_lookup+0x1da/0x340 [ 61.127921][ C1] proc_root_lookup+0x20/0x60 [ 61.134409][ C1] __lookup_slow+0x256/0x490 [ 61.140825][ C1] walk_component+0x418/0x6a0 [ 61.147311][ C1] link_path_walk.part.0+0x4f1/0xb50 [ 61.154397][ C1] path_openat+0x25a/0x27d0 [ 61.160713][ C1] do_filp_open+0x192/0x260 [ 61.167032][ C1] do_sys_openat2+0x585/0x7d0 [ 61.173514][ C1] do_sys_open+0xc3/0x140 [ 61.179657][ C1] do_syscall_64+0xf6/0x7d0 [ 61.185978][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 61.193691][ C1] SOFTIRQ-ON-W at: [ 61.197749][ C1] lock_acquire+0x1f2/0x8f0 [ 61.204092][ C1] _raw_spin_lock+0x2a/0x40 [ 61.210430][ C1] proc_pid_make_inode+0x1f9/0x3c0 [ 61.217350][ C1] proc_pid_instantiate+0x51/0x150 [ 61.224271][ C1] proc_pid_lookup+0x1da/0x340 [ 61.230923][ C1] proc_root_lookup+0x20/0x60 [ 61.237402][ C1] __lookup_slow+0x256/0x490 [ 61.243802][ C1] walk_component+0x418/0x6a0 [ 61.250292][ C1] link_path_walk.part.0+0x4f1/0xb50 [ 61.257374][ C1] path_openat+0x25a/0x27d0 [ 61.263865][ C1] do_filp_open+0x192/0x260 [ 61.270185][ C1] do_sys_openat2+0x585/0x7d0 [ 61.276684][ C1] do_sys_open+0xc3/0x140 [ 61.282949][ C1] do_syscall_64+0xf6/0x7d0 [ 61.289321][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 61.297190][ C1] INITIAL USE at: [ 61.301237][ C1] lock_acquire+0x1f2/0x8f0 [ 61.307481][ C1] _raw_spin_lock_irqsave+0x8c/0xbf [ 61.314419][ C1] __wake_up_common_lock+0xb4/0x130 [ 61.321342][ C1] do_notify_parent+0x19e/0xe60 [ 61.327921][ C1] do_exit+0x238f/0x2dd0 [ 61.333886][ C1] call_usermodehelper_exec_async+0x507/0x710 [ 61.341665][ C1] ret_from_fork+0x24/0x30 [ 61.347798][ C1] } [ 61.350367][ C1] ... key at: [] __key.53786+0x0/0x40 [ 61.357887][ C1] ... acquired at: [ 61.361760][ C1] _raw_spin_lock+0x2a/0x40 [ 61.366414][ C1] io_submit_one+0xc1b/0x2ec0 [ 61.371239][ C1] __ia32_compat_sys_io_submit+0x1bf/0x530 [ 61.377193][ C1] do_fast_syscall_32+0x270/0xe90 [ 61.382475][ C1] entry_SYSENTER_compat+0x70/0x7f [ 61.387727][ C1] [ 61.390029][ C1] -> (&ctx->ctx_lock){..-.}-{2:2} { [ 61.395206][ C1] IN-SOFTIRQ-W at: [ 61.399181][ C1] lock_acquire+0x1f2/0x8f0 [ 61.405439][ C1] _raw_spin_lock_irq+0x5b/0x80 [ 61.412071][ C1] free_ioctx_users+0x2b/0x450 [ 61.418483][ C1] percpu_ref_switch_to_atomic_rcu+0x494/0x540 [ 61.426448][ C1] rcu_core+0x59f/0x1370 [ 61.432332][ C1] __do_softirq+0x26c/0x9f7 [ 61.438468][ C1] irq_exit+0x192/0x1d0 [ 61.444260][ C1] smp_apic_timer_interrupt+0x19e/0x600 [ 61.451432][ C1] apic_timer_interrupt+0xf/0x20 [ 61.458021][ C1] native_safe_halt+0xe/0x10 [ 61.464245][ C1] default_idle+0x49/0x350 [ 61.470291][ C1] do_idle+0x393/0x690 [ 61.475987][ C1] cpu_startup_entry+0x14/0x20 [ 61.482410][ C1] start_secondary+0x2f3/0x400 [ 61.488821][ C1] secondary_startup_64+0xa4/0xb0 [ 61.495483][ C1] INITIAL USE at: [ 61.499359][ C1] lock_acquire+0x1f2/0x8f0 [ 61.505404][ C1] _raw_spin_lock_irq+0x5b/0x80 [ 61.511945][ C1] io_submit_one+0xbd6/0x2ec0 [ 61.518200][ C1] __ia32_compat_sys_io_submit+0x1bf/0x530 [ 61.525567][ C1] do_fast_syscall_32+0x270/0xe90 [ 61.532434][ C1] entry_SYSENTER_compat+0x70/0x7f [ 61.539109][ C1] } [ 61.541759][ C1] ... key at: [] __key.55262+0x0/0x40 [ 61.549520][ C1] ... acquired at: [ 61.553379][ C1] mark_lock+0x624/0xf10 [ 61.557784][ C1] __lock_acquire+0x1d28/0x4e00 [ 61.562917][ C1] lock_acquire+0x1f2/0x8f0 [ 61.567577][ C1] _raw_spin_lock_irq+0x5b/0x80 [ 61.572593][ C1] free_ioctx_users+0x2b/0x450 [ 61.577515][ C1] percpu_ref_switch_to_atomic_rcu+0x494/0x540 [ 61.583827][ C1] rcu_core+0x59f/0x1370 [ 61.588319][ C1] __do_softirq+0x26c/0x9f7 [ 61.593114][ C1] irq_exit+0x192/0x1d0 [ 61.597424][ C1] smp_apic_timer_interrupt+0x19e/0x600 [ 61.603121][ C1] apic_timer_interrupt+0xf/0x20 [ 61.608217][ C1] native_safe_halt+0xe/0x10 [ 61.612966][ C1] default_idle+0x49/0x350 [ 61.617558][ C1] do_idle+0x393/0x690 [ 61.621774][ C1] cpu_startup_entry+0x14/0x20 [ 61.626685][ C1] start_secondary+0x2f3/0x400 [ 61.631605][ C1] secondary_startup_64+0xa4/0xb0 [ 61.636781][ C1] [ 61.639094][ C1] [ 61.639094][ C1] stack backtrace: [ 61.644963][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-syzkaller #0 [ 61.652605][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.662995][ C1] Call Trace: [ 61.666257][ C1] [ 61.669096][ C1] dump_stack+0x188/0x20d [ 61.673418][ C1] check_usage_forwards.cold+0x20/0x29 [ 61.678919][ C1] ? check_usage_backwards+0x4e0/0x4e0 [ 61.684892][ C1] ? stack_trace_consume_entry+0x160/0x160 [ 61.690796][ C1] ? __read_once_size_nocheck.constprop.0+0x10/0x10 [ 61.697429][ C1] ? get_stack_info+0x32/0x13e [ 61.702258][ C1] ? save_trace+0x42/0x9f0 [ 61.706654][ C1] mark_lock+0x624/0xf10 [ 61.710935][ C1] ? check_usage_backwards+0x4e0/0x4e0 [ 61.716410][ C1] ? print_usage_bug+0x240/0x240 [ 61.721412][ C1] ? print_usage_bug+0x240/0x240 [ 61.726326][ C1] ? mark_lock+0x12b/0xf10 [ 61.730769][ C1] __lock_acquire+0x1d28/0x4e00 [ 61.735751][ C1] ? mark_held_locks+0xe0/0xe0 [ 61.740524][ C1] ? __wake_up_common_lock+0xde/0x130 [ 61.745874][ C1] lock_acquire+0x1f2/0x8f0 [ 61.750429][ C1] ? free_ioctx_users+0x2b/0x450 [ 61.755384][ C1] ? lock_release+0x800/0x800 [ 61.760141][ C1] ? lock_acquire+0x1f2/0x8f0 [ 61.764799][ C1] ? percpu_ref_switch_to_atomic_rcu+0x209/0x540 [ 61.771117][ C1] ? lock_release+0x800/0x800 [ 61.775781][ C1] ? _raw_spin_unlock_irqrestore+0x62/0xe0 [ 61.781929][ C1] _raw_spin_lock_irq+0x5b/0x80 [ 61.788158][ C1] ? free_ioctx_users+0x2b/0x450 [ 61.793279][ C1] free_ioctx_users+0x2b/0x450 [ 61.798119][ C1] percpu_ref_switch_to_atomic_rcu+0x494/0x540 [ 61.804340][ C1] rcu_core+0x59f/0x1370 [ 61.808562][ C1] ? __rcu_read_unlock+0x700/0x700 [ 61.813876][ C1] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 61.819451][ C1] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.825502][ C1] ? run_rebalance_domains+0x202/0x2c0 [ 61.830954][ C1] __do_softirq+0x26c/0x9f7 [ 61.835733][ C1] irq_exit+0x192/0x1d0 [ 61.840016][ C1] smp_apic_timer_interrupt+0x19e/0x600 [ 61.846352][ C1] apic_timer_interrupt+0xf/0x20 [ 61.851446][ C1] [ 61.854928][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 61.860554][ C1] Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d d4 2e 5a 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d c4 2e 5a 00 fb f4 cc 41 56 41 55 41 54 55 53 e8 13 b3 92 f9 e8 1e 82 ca fb 0f 1f [ 61.880438][ C1] RSP: 0018:ffffc90000d3fdb8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 [ 61.888929][ C1] RAX: 1ffffffff132925f RBX: ffff8880a95f2340 RCX: 0000000000000000 [ 61.897153][ C1] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a95f2c04 [ 61.905367][ C1] RBP: dffffc0000000000 R08: ffff8880a95f2340 R09: 0000000000000000 [ 61.913555][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: ffffed10152be468 [ 61.921695][ C1] R13: 0000000000000001 R14: ffffffff8a88dfc0 R15: 0000000000000000 [ 61.929886][ C1] default_idle+0x49/0x350 [ 61.934285][ C1] do_idle+0x393/0x690 [ 61.938427][ C1] ? arch_cpu_idle_exit+0x70/0x70 [ 61.943458][ C1] cpu_startup_entry+0x14/0x20 [ 61.948370][ C1] start_secondary+0x2f3/0x400 [ 61.953167][ C1] ? set_cpu_sibling_map+0x1ed0/0x1ed0 [ 61.958615][ C1] secondary_startup_64+0xa4/0xb0