Starting Load/Save RF Kill Switch Status... Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.2' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 65.887216][ C0] [ 65.889691][ C0] ======================================================== [ 65.896897][ C0] WARNING: possible irq lock inversion dependency detected [ 65.904067][ C0] 5.6.0-syzkaller #0 Not tainted [ 65.909026][ C0] -------------------------------------------------------- [ 65.916195][ C0] swapper/0/0 just changed the state of lock: [ 65.922235][ C0] ffff888095bf3cd8 (&ctx->ctx_lock){..-.}-{2:2}, at: free_ioctx_users+0x2b/0x450 [ 65.931336][ C0] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 65.938846][ C0] (&pid->wait_pidfd){+.+.}-{2:2} [ 65.938852][ C0] [ 65.938852][ C0] [ 65.938852][ C0] and interrupts could create inverse lock ordering between them. [ 65.938852][ C0] [ 65.958448][ C0] [ 65.958448][ C0] other info that might help us debug this: [ 65.966494][ C0] Possible interrupt unsafe locking scenario: [ 65.966494][ C0] [ 65.974934][ C0] CPU0 CPU1 [ 65.980331][ C0] ---- ---- [ 65.985692][ C0] lock(&pid->wait_pidfd); [ 65.990177][ C0] local_irq_disable(); [ 65.996911][ C0] lock(&ctx->ctx_lock); [ 66.003748][ C0] lock(&pid->wait_pidfd); [ 66.011053][ C0] [ 66.014494][ C0] lock(&ctx->ctx_lock); [ 66.018977][ C0] [ 66.018977][ C0] *** DEADLOCK *** [ 66.018977][ C0] [ 66.027189][ C0] 2 locks held by swapper/0/0: [ 66.031937][ C0] #0: ffffffff899bbaa0 (rcu_callback){....}-{0:0}, at: rcu_core+0x520/0x1370 [ 66.040790][ C0] #1: ffffffff899bbbc0 (rcu_read_lock){....}-{1:2}, at: percpu_ref_switch_to_atomic_rcu+0x209/0x540 [ 66.051762][ C0] [ 66.051762][ C0] the shortest dependencies between 2nd lock and 1st lock: [ 66.061259][ C0] -> (&pid->wait_pidfd){+.+.}-{2:2} { [ 66.066866][ C0] HARDIRQ-ON-W at: [ 66.071049][ C0] lock_acquire+0x1f2/0x8f0 [ 66.077489][ C0] _raw_spin_lock+0x2a/0x40 [ 66.083812][ C0] proc_pid_make_inode+0x1f9/0x3c0 [ 66.090738][ C0] proc_pid_instantiate+0x51/0x150 [ 66.097671][ C0] proc_pid_lookup+0x1da/0x340 [ 66.104240][ C0] proc_root_lookup+0x20/0x60 [ 66.110748][ C0] __lookup_slow+0x256/0x490 [ 66.117288][ C0] walk_component+0x418/0x6a0 [ 66.123803][ C0] link_path_walk.part.0+0x4f1/0xb50 [ 66.130897][ C0] path_openat+0x25a/0x27d0 [ 66.137216][ C0] do_filp_open+0x192/0x260 [ 66.143555][ C0] do_sys_openat2+0x585/0x7d0 [ 66.150159][ C0] do_sys_open+0xc3/0x140 [ 66.156294][ C0] do_syscall_64+0xf6/0x7d0 [ 66.162737][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 66.170432][ C0] SOFTIRQ-ON-W at: [ 66.174525][ C0] lock_acquire+0x1f2/0x8f0 [ 66.180962][ C0] _raw_spin_lock+0x2a/0x40 [ 66.187293][ C0] proc_pid_make_inode+0x1f9/0x3c0 [ 66.194447][ C0] proc_pid_instantiate+0x51/0x150 [ 66.201370][ C0] proc_pid_lookup+0x1da/0x340 [ 66.208098][ C0] proc_root_lookup+0x20/0x60 [ 66.214714][ C0] __lookup_slow+0x256/0x490 [ 66.221242][ C0] walk_component+0x418/0x6a0 [ 66.227812][ C0] link_path_walk.part.0+0x4f1/0xb50 [ 66.234900][ C0] path_openat+0x25a/0x27d0 [ 66.241205][ C0] do_filp_open+0x192/0x260 [ 66.247527][ C0] do_sys_openat2+0x585/0x7d0 [ 66.254010][ C0] do_sys_open+0xc3/0x140 [ 66.260212][ C0] do_syscall_64+0xf6/0x7d0 [ 66.266550][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 66.274245][ C0] INITIAL USE at: [ 66.278216][ C0] lock_acquire+0x1f2/0x8f0 [ 66.284433][ C0] _raw_spin_lock_irqsave+0x8c/0xbf [ 66.291343][ C0] __wake_up_common_lock+0xb4/0x130 [ 66.298278][ C0] do_notify_parent+0x19e/0xe60 [ 66.304857][ C0] do_exit+0x238f/0x2dd0 [ 66.310814][ C0] call_usermodehelper_exec_async+0x507/0x710 [ 66.318762][ C0] ret_from_fork+0x24/0x30 [ 66.324914][ C0] } [ 66.327503][ C0] ... key at: [] __key.53827+0x0/0x40 [ 66.335156][ C0] ... acquired at: [ 66.339044][ C0] _raw_spin_lock+0x2a/0x40 [ 66.343703][ C0] io_submit_one+0xc1b/0x2ec0 [ 66.348531][ C0] __x64_sys_io_submit+0x1bd/0x540 [ 66.353792][ C0] do_syscall_64+0xf6/0x7d0 [ 66.358470][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 66.364516][ C0] [ 66.366823][ C0] -> (&ctx->ctx_lock){..-.}-{2:2} { [ 66.372127][ C0] IN-SOFTIRQ-W at: [ 66.376236][ C0] lock_acquire+0x1f2/0x8f0 [ 66.382395][ C0] _raw_spin_lock_irq+0x5b/0x80 [ 66.388957][ C0] free_ioctx_users+0x2b/0x450 [ 66.395351][ C0] percpu_ref_switch_to_atomic_rcu+0x494/0x540 [ 66.403163][ C0] rcu_core+0x59f/0x1370 [ 66.409190][ C0] __do_softirq+0x26c/0x9f7 [ 66.415470][ C0] irq_exit+0x192/0x1d0 [ 66.421268][ C0] smp_apic_timer_interrupt+0x19e/0x600 [ 66.428596][ C0] apic_timer_interrupt+0xf/0x20 [ 66.435177][ C0] native_safe_halt+0xe/0x10 [ 66.441594][ C0] default_idle+0x49/0x350 [ 66.447853][ C0] do_idle+0x393/0x690 [ 66.453579][ C0] cpu_startup_entry+0x14/0x20 [ 66.460085][ C0] start_kernel+0x867/0x8a1 [ 66.466237][ C0] secondary_startup_64+0xa4/0xb0 [ 66.472936][ C0] INITIAL USE at: [ 66.476849][ C0] lock_acquire+0x1f2/0x8f0 [ 66.482911][ C0] _raw_spin_lock_irq+0x5b/0x80 [ 66.489395][ C0] io_submit_one+0xbd6/0x2ec0 [ 66.495653][ C0] __x64_sys_io_submit+0x1bd/0x540 [ 66.502327][ C0] do_syscall_64+0xf6/0x7d0 [ 66.508401][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 66.515888][ C0] } [ 66.518398][ C0] ... key at: [] __key.55303+0x0/0x40 [ 66.525860][ C0] ... acquired at: [ 66.529678][ C0] mark_lock+0x624/0xf10 [ 66.534243][ C0] __lock_acquire+0x1d28/0x4e00 [ 66.539280][ C0] lock_acquire+0x1f2/0x8f0 [ 66.543973][ C0] _raw_spin_lock_irq+0x5b/0x80 [ 66.549060][ C0] free_ioctx_users+0x2b/0x450 [ 66.554010][ C0] percpu_ref_switch_to_atomic_rcu+0x494/0x540 [ 66.560326][ C0] rcu_core+0x59f/0x1370 [ 66.564718][ C0] __do_softirq+0x26c/0x9f7 [ 66.569380][ C0] irq_exit+0x192/0x1d0 [ 66.573702][ C0] smp_apic_timer_interrupt+0x19e/0x600 [ 66.579397][ C0] apic_timer_interrupt+0xf/0x20 [ 66.584487][ C0] native_safe_halt+0xe/0x10 [ 66.589228][ C0] default_idle+0x49/0x350 [ 66.593814][ C0] do_idle+0x393/0x690 [ 66.598032][ C0] cpu_startup_entry+0x14/0x20 [ 66.602960][ C0] start_kernel+0x867/0x8a1 [ 66.607617][ C0] secondary_startup_64+0xa4/0xb0 [ 66.612793][ C0] [ 66.615094][ C0] [ 66.615094][ C0] stack backtrace: [ 66.620970][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-syzkaller #0 [ 66.628487][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.638547][ C0] Call Trace: [ 66.641809][ C0] [ 66.644646][ C0] dump_stack+0x188/0x20d [ 66.649134][ C0] check_usage_forwards.cold+0x20/0x29 [ 66.654588][ C0] ? check_usage_backwards+0x4e0/0x4e0 [ 66.660029][ C0] ? stack_trace_consume_entry+0x160/0x160 [ 66.665825][ C0] ? __read_once_size_nocheck.constprop.0+0x10/0x10 [ 66.672423][ C0] ? save_trace+0x42/0x9f0 [ 66.676822][ C0] mark_lock+0x624/0xf10 [ 66.681103][ C0] ? check_usage_backwards+0x4e0/0x4e0 [ 66.686550][ C0] ? print_usage_bug+0x240/0x240 [ 66.691496][ C0] ? print_usage_bug+0x240/0x240 [ 66.696415][ C0] ? mark_lock+0x12b/0xf10 [ 66.700986][ C0] __lock_acquire+0x1d28/0x4e00 [ 66.705836][ C0] ? mark_held_locks+0xe0/0xe0 [ 66.710581][ C0] ? __wake_up_common_lock+0xde/0x130 [ 66.715929][ C0] lock_acquire+0x1f2/0x8f0 [ 66.720425][ C0] ? free_ioctx_users+0x2b/0x450 [ 66.725353][ C0] ? lock_release+0x800/0x800 [ 66.730004][ C0] ? lock_acquire+0x1f2/0x8f0 [ 66.734671][ C0] ? percpu_ref_switch_to_atomic_rcu+0x209/0x540 [ 66.740981][ C0] ? lock_release+0x800/0x800 [ 66.745673][ C0] ? _raw_spin_unlock_irqrestore+0x62/0xe0 [ 66.751479][ C0] _raw_spin_lock_irq+0x5b/0x80 [ 66.756316][ C0] ? free_ioctx_users+0x2b/0x450 [ 66.761229][ C0] free_ioctx_users+0x2b/0x450 [ 66.765975][ C0] percpu_ref_switch_to_atomic_rcu+0x494/0x540 [ 66.772138][ C0] rcu_core+0x59f/0x1370 [ 66.776366][ C0] ? __rcu_read_unlock+0x700/0x700 [ 66.781460][ C0] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 66.786982][ C0] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 66.792968][ C0] ? run_rebalance_domains+0x202/0x2c0 [ 66.798430][ C0] __do_softirq+0x26c/0x9f7 [ 66.802919][ C0] irq_exit+0x192/0x1d0 [ 66.807064][ C0] smp_apic_timer_interrupt+0x19e/0x600 [ 66.812693][ C0] apic_timer_interrupt+0xf/0x20 [ 66.817628][ C0] [ 66.820565][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 66.825914][ C0] Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d d4 f2 59 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d c4 f2 59 00 fb f4 cc 41 56 41 55 41 54 55 53 e8 33 77 92 f9 e8 3e b3 ca fb 0f 1f [ 66.845501][ C0] RSP: 0018:ffffffff89807d98 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 [ 66.853902][ C0] RAX: 1ffffffff132925f RBX: ffffffff898864c0 RCX: 0000000000000000 [ 66.861852][ C0] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff89886d84 [ 66.869814][ C0] RBP: dffffc0000000000 R08: ffffffff898864c0 R09: 0000000000000000 [ 66.877777][ C0] R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff1310c98 [ 66.885872][ C0] R13: 0000000000000000 R14: ffffffff8a88e980 R15: 0000000000000000 [ 66.893860][ C0] default_idle+0x49/0x350 [ 66.898263][ C0] do_idle+0x393/0x690 [ 66.902437][ C0] ? rcu_read_lock_held+0x9c/0xb0 [ 66.907565][ C0] ? arch_cpu_idle_exit+0x70/0x70 [ 66.912572][ C0] ? schedule+0xe7/0x2a0 [ 66.916795][ C0] ? trace_init_perf_perm_irq_work_exit+0xe/0xe [ 66.923018][ C0] cpu_startup_entry+0x14/0x20 [ 66.927760][ C0] start_kernel+0x867/0x8a1 [ 66.932257][ C0] ? mem_encrypt_init+0x5/0x5 [ 66.936915][ C0] ? x86_family+0x3d/0x50 [ 66.94