[ 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. Starting Load/Save RF Kill Switch Status... Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.62' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 40.823334][ C0] [ 40.825693][ C0] ======================================================== [ 40.832996][ C0] WARNING: possible irq lock inversion dependency detected [ 40.840165][ C0] 5.6.0-syzkaller #0 Not tainted [ 40.845081][ C0] -------------------------------------------------------- [ 40.852239][ C0] swapper/0/0 just changed the state of lock: [ 40.858272][ C0] ffff8880a700dcd8 (&ctx->ctx_lock){..-.}-{2:2}, at: free_ioctx_users+0x30/0x1c0 [ 40.867356][ C0] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 40.874881][ C0] (&pid->wait_pidfd){+.+.}-{2:2} [ 40.874886][ C0] [ 40.874886][ C0] [ 40.874886][ C0] and interrupts could create inverse lock ordering between them. [ 40.874886][ C0] [ 40.894177][ C0] [ 40.894177][ C0] other info that might help us debug this: [ 40.902219][ C0] Possible interrupt unsafe locking scenario: [ 40.902219][ C0] [ 40.910508][ C0] CPU0 CPU1 [ 40.915914][ C0] ---- ---- [ 40.921294][ C0] lock(&pid->wait_pidfd); [ 40.925777][ C0] local_irq_disable(); [ 40.932503][ C0] lock(&ctx->ctx_lock); [ 40.939320][ C0] lock(&pid->wait_pidfd); [ 40.946306][ C0] [ 40.949731][ C0] lock(&ctx->ctx_lock); [ 40.954252][ C0] [ 40.954252][ C0] *** DEADLOCK *** [ 40.954252][ C0] [ 40.962370][ C0] 2 locks held by swapper/0/0: [ 40.967098][ C0] #0: ffffffff892e6be0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x0/0x30 [ 40.976291][ C0] #1: ffffffff892e6b90 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 [ 40.985547][ C0] [ 40.985547][ C0] the shortest dependencies between 2nd lock and 1st lock: [ 40.994907][ C0] -> (&pid->wait_pidfd){+.+.}-{2:2} { [ 41.000347][ C0] HARDIRQ-ON-W at: [ 41.004389][ C0] lock_acquire+0x169/0x480 [ 41.010684][ C0] _raw_spin_lock+0x2a/0x40 [ 41.016979][ C0] proc_pid_make_inode+0x187/0x2d0 [ 41.023893][ C0] proc_pid_instantiate+0x4b/0x1a0 [ 41.030805][ C0] proc_pid_lookup+0x218/0x2f0 [ 41.037359][ C0] proc_root_lookup+0x1b/0x50 [ 41.043829][ C0] __lookup_slow+0x240/0x370 [ 41.050209][ C0] walk_component+0x442/0x680 [ 41.056687][ C0] link_path_walk+0x66d/0xba0 [ 41.063166][ C0] path_openat+0x21d/0x38b0 [ 41.069461][ C0] do_filp_open+0x191/0x3a0 [ 41.075757][ C0] do_sys_openat2+0x463/0x770 [ 41.082234][ C0] __x64_sys_open+0x1af/0x1e0 [ 41.088703][ C0] do_syscall_64+0xf3/0x1b0 [ 41.095013][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 41.102697][ C0] SOFTIRQ-ON-W at: [ 41.106736][ C0] lock_acquire+0x169/0x480 [ 41.113044][ C0] _raw_spin_lock+0x2a/0x40 [ 41.119339][ C0] proc_pid_make_inode+0x187/0x2d0 [ 41.126253][ C0] proc_pid_instantiate+0x4b/0x1a0 [ 41.133160][ C0] proc_pid_lookup+0x218/0x2f0 [ 41.139718][ C0] proc_root_lookup+0x1b/0x50 [ 41.146194][ C0] __lookup_slow+0x240/0x370 [ 41.152587][ C0] walk_component+0x442/0x680 [ 41.159076][ C0] link_path_walk+0x66d/0xba0 [ 41.165557][ C0] path_openat+0x21d/0x38b0 [ 41.171854][ C0] do_filp_open+0x191/0x3a0 [ 41.178163][ C0] do_sys_openat2+0x463/0x770 [ 41.184637][ C0] __x64_sys_open+0x1af/0x1e0 [ 41.191114][ C0] do_syscall_64+0xf3/0x1b0 [ 41.197424][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 41.205111][ C0] INITIAL USE at: [ 41.209064][ C0] lock_acquire+0x169/0x480 [ 41.215297][ C0] _raw_spin_lock_irqsave+0x9e/0xc0 [ 41.222200][ C0] __wake_up+0xb8/0x150 [ 41.228066][ C0] do_notify_parent+0x167/0xce0 [ 41.234624][ C0] do_exit+0x12c5/0x1f80 [ 41.240572][ C0] call_usermodehelper_exec_async+0x47c/0x480 [ 41.248341][ C0] ret_from_fork+0x24/0x30 [ 41.254459][ C0] } [ 41.257035][ C0] ... key at: [] alloc_pid.__key+0x0/0x10 [ 41.264904][ C0] ... acquired at: [ 41.268795][ C0] lock_acquire+0x169/0x480 [ 41.273443][ C0] _raw_spin_lock+0x2a/0x40 [ 41.278088][ C0] io_submit_one+0x10f5/0x1a80 [ 41.282991][ C0] __se_sys_io_submit+0x117/0x220 [ 41.288168][ C0] do_syscall_64+0xf3/0x1b0 [ 41.292812][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 41.298844][ C0] [ 41.301140][ C0] -> (&ctx->ctx_lock){..-.}-{2:2} { [ 41.306335][ C0] IN-SOFTIRQ-W at: [ 41.310288][ C0] lock_acquire+0x169/0x480 [ 41.316412][ C0] _raw_spin_lock_irq+0x67/0x80 [ 41.322881][ C0] free_ioctx_users+0x30/0x1c0 [ 41.329275][ C0] percpu_ref_put+0x18d/0x1a0 [ 41.335569][ C0] rcu_core+0x816/0x1120 [ 41.341431][ C0] __do_softirq+0x268/0x80c [ 41.347551][ C0] irq_exit+0x223/0x230 [ 41.353324][ C0] smp_apic_timer_interrupt+0x113/0x280 [ 41.360484][ C0] apic_timer_interrupt+0xf/0x20 [ 41.367155][ C0] native_safe_halt+0xe/0x10 [ 41.373376][ C0] default_idle+0x4c/0x70 [ 41.379321][ C0] do_idle+0x1ee/0x650 [ 41.385010][ C0] cpu_startup_entry+0x15/0x20 [ 41.391391][ C0] start_kernel+0x674/0x774 [ 41.397600][ C0] secondary_startup_64+0xa4/0xb0 [ 41.404349][ C0] INITIAL USE at: [ 41.408215][ C0] lock_acquire+0x169/0x480 [ 41.414249][ C0] _raw_spin_lock_irq+0x67/0x80 [ 41.420641][ C0] io_submit_one+0x10cb/0x1a80 [ 41.426936][ C0] __se_sys_io_submit+0x117/0x220 [ 41.433587][ C0] do_syscall_64+0xf3/0x1b0 [ 41.439621][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 41.447050][ C0] } [ 41.449525][ C0] ... key at: [] ioctx_alloc.__key+0x0/0x10 [ 41.457476][ C0] ... acquired at: [ 41.461255][ C0] mark_lock+0x529/0x1b00 [ 41.465737][ C0] __lock_acquire+0xaa7/0x2b90 [ 41.470693][ C0] lock_acquire+0x169/0x480 [ 41.475368][ C0] _raw_spin_lock_irq+0x67/0x80 [ 41.480376][ C0] free_ioctx_users+0x30/0x1c0 [ 41.485289][ C0] percpu_ref_put+0x18d/0x1a0 [ 41.490122][ C0] rcu_core+0x816/0x1120 [ 41.494631][ C0] __do_softirq+0x268/0x80c [ 41.499279][ C0] irq_exit+0x223/0x230 [ 41.503685][ C0] smp_apic_timer_interrupt+0x113/0x280 [ 41.509379][ C0] apic_timer_interrupt+0xf/0x20 [ 41.514465][ C0] native_safe_halt+0xe/0x10 [ 41.519204][ C0] default_idle+0x4c/0x70 [ 41.523681][ C0] do_idle+0x1ee/0x650 [ 41.527891][ C0] cpu_startup_entry+0x15/0x20 [ 41.532798][ C0] start_kernel+0x674/0x774 [ 41.537453][ C0] secondary_startup_64+0xa4/0xb0 [ 41.542615][ C0] [ 41.544913][ C0] [ 41.544913][ C0] stack backtrace: [ 41.550776][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-syzkaller #0 [ 41.558282][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.568585][ C0] Call Trace: [ 41.571848][ C0] [ 41.574681][ C0] dump_stack+0x1e9/0x30e [ 41.578999][ C0] print_irq_inversion_bug+0xb67/0xe90 [ 41.584449][ C0] ? arch_stack_walk+0xb4/0xe0 [ 41.589307][ C0] ? secondary_startup_64+0xa4/0xb0 [ 41.594490][ C0] check_usage_forwards+0x13f/0x240 [ 41.599664][ C0] ? save_trace+0x49/0xb60 [ 41.604208][ C0] mark_lock+0x529/0x1b00 [ 41.608525][ C0] ? check_usage_backwards+0x240/0x240 [ 41.613955][ C0] ? mark_lock+0x102/0x1b00 [ 41.618431][ C0] ? __lock_acquire+0x116c/0x2b90 [ 41.623540][ C0] __lock_acquire+0xaa7/0x2b90 [ 41.628290][ C0] ? pcpu_block_update+0x564/0x890 [ 41.633384][ C0] lock_acquire+0x169/0x480 [ 41.637890][ C0] ? free_ioctx_users+0x30/0x1c0 [ 41.642805][ C0] ? rcu_lock_acquire+0x5/0x30 [ 41.647543][ C0] ? trace_irq_disable_rcuidle+0x1f/0x1d0 [ 41.653235][ C0] ? percpu_ref_noop_confirm_switch+0x10/0x10 [ 41.659299][ C0] _raw_spin_lock_irq+0x67/0x80 [ 41.664484][ C0] ? free_ioctx_users+0x30/0x1c0 [ 41.669466][ C0] free_ioctx_users+0x30/0x1c0 [ 41.674324][ C0] ? percpu_ref_noop_confirm_switch+0x10/0x10 [ 41.680620][ C0] ? percpu_ref_noop_confirm_switch+0x10/0x10 [ 41.686680][ C0] percpu_ref_put+0x18d/0x1a0 [ 41.691336][ C0] rcu_core+0x816/0x1120 [ 41.695633][ C0] __do_softirq+0x268/0x80c [ 41.700127][ C0] ? irq_exit+0x223/0x230 [ 41.704445][ C0] irq_exit+0x223/0x230 [ 41.708589][ C0] smp_apic_timer_interrupt+0x113/0x280 [ 41.714105][ C0] apic_timer_interrupt+0xf/0x20 [ 41.719012][ C0] [ 41.721957][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 41.727358][ C0] Code: 80 e1 07 80 c1 03 38 c1 7c bc 48 89 df e8 aa 1f a8 f9 eb b2 cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 96 04 57 00 fb f4 90 e9 07 00 00 00 0f 00 2d 86 04 57 00 f4 c3 cc cc 41 56 53 65 [ 41.746974][ C0] RSP: 0018:ffffffff89207e68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 41.755375][ C0] RAX: 1ffffffff1257401 RBX: ffffffff89281b00 RCX: dffffc0000000000 [ 41.763336][ C0] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff89282364 [ 41.771293][ C0] RBP: ffffffff896b99a0 R08: ffffffff817b9ae0 R09: fffffbfff1250361 [ 41.779770][ C0] R10: fffffbfff1250361 R11: 0000000000000000 R12: 1ffffffff1250360 [ 41.788005][ C0] R13: dffffc0000000000 R14: 1ffffffff12573ff R15: 0000000000000000 [ 41.795977][ C0] ? trace_hardirqs_on+0x30/0x70 [ 41.800888][ C0] default_idle+0x4c/0x70 [ 41.805195][ C0] do_idle+0x1ee/0x650 [ 41.809237][ C0] cpu_startup_entry+0x15/0x20 [ 41.813971][ C0] ? time_init+0x33/0x33 [ 41.818183][ C0] start_kernel+0x674/0x774 [ 41.822658][ C0] secondary_startup_64+0xa4/0xb0