[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.124' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 44.289289][ C1] [ 44.291634][ C1] ======================================================== [ 44.298973][ C1] WARNING: possible irq lock inversion dependency detected [ 44.306166][ C1] 5.6.0-syzkaller #0 Not tainted [ 44.311212][ C1] -------------------------------------------------------- [ 44.318651][ C1] swapper/1/0 just changed the state of lock: [ 44.324844][ C1] ffff8880a9149cd8 (&ctx->ctx_lock){..-.}-{2:2}, at: free_ioctx_users+0x30/0x1c0 [ 44.333949][ C1] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 44.341466][ C1] (&pid->wait_pidfd){+.+.}-{2:2} [ 44.341474][ C1] [ 44.341474][ C1] [ 44.341474][ C1] and interrupts could create inverse lock ordering between them. [ 44.341474][ C1] [ 44.361006][ C1] [ 44.361006][ C1] other info that might help us debug this: [ 44.369051][ C1] Possible interrupt unsafe locking scenario: [ 44.369051][ C1] [ 44.377361][ C1] CPU0 CPU1 [ 44.382713][ C1] ---- ---- [ 44.388059][ C1] lock(&pid->wait_pidfd); [ 44.392557][ C1] local_irq_disable(); [ 44.399301][ C1] lock(&ctx->ctx_lock); [ 44.406119][ C1] lock(&pid->wait_pidfd); [ 44.413121][ C1] [ 44.416553][ C1] lock(&ctx->ctx_lock); [ 44.421022][ C1] [ 44.421022][ C1] *** DEADLOCK *** [ 44.421022][ C1] [ 44.429154][ C1] 2 locks held by swapper/1/0: [ 44.434069][ C1] #0: ffffffff892e6c20 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x0/0x30 [ 44.443252][ C1] #1: ffffffff892e6bd0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 [ 44.452522][ C1] [ 44.452522][ C1] the shortest dependencies between 2nd lock and 1st lock: [ 44.461882][ C1] -> (&pid->wait_pidfd){+.+.}-{2:2} { [ 44.467322][ C1] HARDIRQ-ON-W at: [ 44.471364][ C1] lock_acquire+0x169/0x480 [ 44.477675][ C1] _raw_spin_lock+0x2a/0x40 [ 44.484014][ C1] proc_pid_make_inode+0x187/0x2d0 [ 44.490937][ C1] proc_pid_instantiate+0x4b/0x1a0 [ 44.498041][ C1] proc_pid_lookup+0x218/0x2f0 [ 44.504619][ C1] proc_root_lookup+0x1b/0x50 [ 44.511106][ C1] __lookup_slow+0x240/0x370 [ 44.517535][ C1] walk_component+0x442/0x680 [ 44.524015][ C1] link_path_walk+0x66d/0xba0 [ 44.530520][ C1] path_openat+0x21d/0x38b0 [ 44.536827][ C1] do_filp_open+0x191/0x3a0 [ 44.543250][ C1] do_sys_openat2+0x463/0x770 [ 44.549727][ C1] __x64_sys_open+0x1af/0x1e0 [ 44.556206][ C1] do_syscall_64+0xf3/0x1b0 [ 44.562513][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 44.570206][ C1] SOFTIRQ-ON-W at: [ 44.574255][ C1] lock_acquire+0x169/0x480 [ 44.580551][ C1] _raw_spin_lock+0x2a/0x40 [ 44.586865][ C1] proc_pid_make_inode+0x187/0x2d0 [ 44.593880][ C1] proc_pid_instantiate+0x4b/0x1a0 [ 44.600866][ C1] proc_pid_lookup+0x218/0x2f0 [ 44.607430][ C1] proc_root_lookup+0x1b/0x50 [ 44.613902][ C1] __lookup_slow+0x240/0x370 [ 44.620298][ C1] walk_component+0x442/0x680 [ 44.626767][ C1] link_path_walk+0x66d/0xba0 [ 44.633248][ C1] path_openat+0x21d/0x38b0 [ 44.639543][ C1] do_filp_open+0x191/0x3a0 [ 44.645840][ C1] do_sys_openat2+0x463/0x770 [ 44.652511][ C1] __x64_sys_open+0x1af/0x1e0 [ 44.658993][ C1] do_syscall_64+0xf3/0x1b0 [ 44.665304][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 44.672995][ C1] INITIAL USE at: [ 44.676960][ C1] lock_acquire+0x169/0x480 [ 44.683170][ C1] _raw_spin_lock_irqsave+0x9e/0xc0 [ 44.690082][ C1] __wake_up+0xb8/0x150 [ 44.695956][ C1] do_notify_parent+0x167/0xce0 [ 44.702583][ C1] do_exit+0x12c5/0x1f80 [ 44.708655][ C1] call_usermodehelper_exec_async+0x47c/0x480 [ 44.716948][ C1] ret_from_fork+0x24/0x30 [ 44.723120][ C1] } [ 44.725696][ C1] ... key at: [] alloc_pid.__key+0x0/0x10 [ 44.733554][ C1] ... acquired at: [ 44.737440][ C1] lock_acquire+0x169/0x480 [ 44.742163][ C1] _raw_spin_lock+0x2a/0x40 [ 44.746851][ C1] io_submit_one+0x10f5/0x1a80 [ 44.751792][ C1] __se_sys_io_submit+0x117/0x220 [ 44.756970][ C1] do_syscall_64+0xf3/0x1b0 [ 44.761618][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 44.767665][ C1] [ 44.769968][ C1] -> (&ctx->ctx_lock){..-.}-{2:2} { [ 44.775229][ C1] IN-SOFTIRQ-W at: [ 44.779201][ C1] lock_acquire+0x169/0x480 [ 44.785353][ C1] _raw_spin_lock_irq+0x67/0x80 [ 44.791827][ C1] free_ioctx_users+0x30/0x1c0 [ 44.798214][ C1] percpu_ref_put+0x18d/0x1a0 [ 44.804536][ C1] rcu_core+0x816/0x1120 [ 44.810710][ C1] __do_softirq+0x268/0x80c [ 44.816861][ C1] irq_exit+0x223/0x230 [ 44.822664][ C1] smp_apic_timer_interrupt+0x113/0x280 [ 44.829829][ C1] apic_timer_interrupt+0xf/0x20 [ 44.836578][ C1] native_safe_halt+0xe/0x10 [ 44.842791][ C1] default_idle+0x4c/0x70 [ 44.848843][ C1] do_idle+0x1ee/0x650 [ 44.854551][ C1] cpu_startup_entry+0x15/0x20 [ 44.860948][ C1] start_secondary+0x386/0x410 [ 44.867365][ C1] secondary_startup_64+0xa4/0xb0 [ 44.874116][ C1] INITIAL USE at: [ 44.877990][ C1] lock_acquire+0x169/0x480 [ 44.884183][ C1] _raw_spin_lock_irq+0x67/0x80 [ 44.890645][ C1] io_submit_one+0x10cb/0x1a80 [ 44.897054][ C1] __se_sys_io_submit+0x117/0x220 [ 44.903629][ C1] do_syscall_64+0xf3/0x1b0 [ 44.909671][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 44.917097][ C1] } [ 44.919577][ C1] ... key at: [] ioctx_alloc.__key+0x0/0x10 [ 44.927540][ C1] ... acquired at: [ 44.931350][ C1] mark_lock+0x529/0x1b00 [ 44.935897][ C1] __lock_acquire+0xaa7/0x2b90 [ 44.940813][ C1] lock_acquire+0x169/0x480 [ 44.945467][ C1] _raw_spin_lock_irq+0x67/0x80 [ 44.950496][ C1] free_ioctx_users+0x30/0x1c0 [ 44.955443][ C1] percpu_ref_put+0x18d/0x1a0 [ 44.960286][ C1] rcu_core+0x816/0x1120 [ 44.965173][ C1] __do_softirq+0x268/0x80c [ 44.969948][ C1] irq_exit+0x223/0x230 [ 44.974386][ C1] smp_apic_timer_interrupt+0x113/0x280 [ 44.980138][ C1] apic_timer_interrupt+0xf/0x20 [ 44.985378][ C1] native_safe_halt+0xe/0x10 [ 44.990117][ C1] default_idle+0x4c/0x70 [ 44.994718][ C1] do_idle+0x1ee/0x650 [ 44.998931][ C1] cpu_startup_entry+0x15/0x20 [ 45.004156][ C1] start_secondary+0x386/0x410 [ 45.009250][ C1] secondary_startup_64+0xa4/0xb0 [ 45.014421][ C1] [ 45.016748][ C1] [ 45.016748][ C1] stack backtrace: [ 45.022615][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-syzkaller #0 [ 45.030287][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.040336][ C1] Call Trace: [ 45.043599][ C1] [ 45.046433][ C1] dump_stack+0x1e9/0x30e [ 45.050746][ C1] print_irq_inversion_bug+0xb67/0xe90 [ 45.056189][ C1] ? arch_stack_walk+0xb4/0xe0 [ 45.060940][ C1] ? secondary_startup_64+0xa4/0xb0 [ 45.066112][ C1] check_usage_forwards+0x13f/0x240 [ 45.071280][ C1] ? save_trace+0x49/0xb60 [ 45.075668][ C1] mark_lock+0x529/0x1b00 [ 45.079982][ C1] ? check_usage_backwards+0x240/0x240 [ 45.085435][ C1] ? mark_lock+0x102/0x1b00 [ 45.089911][ C1] ? __lock_acquire+0x116c/0x2b90 [ 45.094908][ C1] __lock_acquire+0xaa7/0x2b90 [ 45.099663][ C1] ? pcpu_block_update+0x564/0x890 [ 45.104756][ C1] lock_acquire+0x169/0x480 [ 45.109231][ C1] ? free_ioctx_users+0x30/0x1c0 [ 45.114141][ C1] ? rcu_lock_acquire+0x5/0x30 [ 45.118894][ C1] ? trace_irq_disable_rcuidle+0x1f/0x1d0 [ 45.124830][ C1] ? percpu_ref_noop_confirm_switch+0x10/0x10 [ 45.130996][ C1] _raw_spin_lock_irq+0x67/0x80 [ 45.136259][ C1] ? free_ioctx_users+0x30/0x1c0 [ 45.141322][ C1] free_ioctx_users+0x30/0x1c0 [ 45.146216][ C1] ? percpu_ref_noop_confirm_switch+0x10/0x10 [ 45.152449][ C1] ? percpu_ref_noop_confirm_switch+0x10/0x10 [ 45.158496][ C1] percpu_ref_put+0x18d/0x1a0 [ 45.164972][ C1] rcu_core+0x816/0x1120 [ 45.169195][ C1] __do_softirq+0x268/0x80c [ 45.173673][ C1] ? irq_exit+0x223/0x230 [ 45.177985][ C1] irq_exit+0x223/0x230 [ 45.182127][ C1] smp_apic_timer_interrupt+0x113/0x280 [ 45.187655][ C1] apic_timer_interrupt+0xf/0x20 [ 45.192560][ C1] [ 45.195476][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 45.200835][ C1] Code: 80 e1 07 80 c1 03 38 c1 7c bc 48 89 df e8 4a 29 a7 f9 eb b2 cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 36 c3 58 00 fb f4 90 e9 07 00 00 00 0f 00 2d 26 c3 58 00 f4 c3 cc cc 41 56 53 65 [ 45.220610][ C1] RSP: 0018:ffffc90000d3fe60 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 45.229007][ C1] RAX: 1ffffffff1257409 RBX: ffff8880a9a3c340 RCX: dffffc0000000000 [ 45.236961][ C1] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880a9a3cba4 [ 45.244928][ C1] RBP: ffffffff896b9ee0 R08: ffffffff8178ec90 R09: ffffed1015347869 [ 45.252895][ C1] R10: ffffed1015347869 R11: 0000000000000000 R12: 1ffff11015347868 [ 45.260859][ C1] R13: dffffc0000000000 R14: 1ffffffff1257407 R15: 0000000000000001 [ 45.269049][ C1] ? trace_hardirqs_on+0x30/0x70 [ 45.273970][ C1] default_idle+0x4c/0x70 [ 45.278511][ C1] do_idle+0x1ee/0x650 [ 45.282569][ C1] cpu_startup_entry+0x15/0x20 [ 45.287314][ C1] start_secondary+0x386/0x410 [ 45.292058][ C1] secondary_startup_64+0xa4/0xb0