random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ======================================================== WARNING: possible irq lock inversion dependency detected 4.19.0-rc2+ #229 Not tainted -------------------------------------------------------- swapper/0/0 just changed the state of lock: 00000000c02bddef (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline] 00000000c02bddef (&(&ctx->ctx_lock)->rlock){..-.}, at: free_ioctx_users+0xbc/0x710 fs/aio.c:603 but this lock took another, SOFTIRQ-unsafe lock in the past: (&fiq->waitq){+.+.} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fiq->waitq); local_irq_disable(); lock(&(&ctx->ctx_lock)->rlock); lock(&fiq->waitq); lock(&(&ctx->ctx_lock)->rlock); *** DEADLOCK *** 2 locks held by swapper/0/0: #0: 0000000077c9a56b (rcu_callback){....}, at: __rcu_reclaim kernel/rcu/rcu.h:226 [inline] #0: 0000000077c9a56b (rcu_callback){....}, at: rcu_do_batch kernel/rcu/tree.c:2576 [inline] #0: 0000000077c9a56b (rcu_callback){....}, at: invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] #0: 0000000077c9a56b (rcu_callback){....}, at: __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] #0: 0000000077c9a56b (rcu_callback){....}, at: rcu_process_callbacks+0x1012/0x2670 kernel/rcu/tree.c:2864 #1: 0000000031dcf310 (rcu_read_lock_sched){....}, at: percpu_ref_call_confirm_rcu lib/percpu-refcount.c:119 [inline] #1: 0000000031dcf310 (rcu_read_lock_sched){....}, at: percpu_ref_switch_to_atomic_rcu+0x2b7/0x820 lib/percpu-refcount.c:158 the shortest dependencies between 2nd lock and 1st lock: -> (&fiq->waitq){+.+.} ops: 4 { HARDIRQ-ON-W at: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] flush_bg_queue+0x389/0x650 fs/fuse/dev.c:364 fuse_request_send_background_locked+0x2f5/0x5a0 fs/fuse/dev.c:598 fuse_request_send_background+0x135/0x180 fs/fuse/dev.c:606 cuse_send_init fs/fuse/cuse.c:458 [inline] cuse_channel_open+0x6b0/0x963 fs/fuse/cuse.c:518 misc_open+0x3ca/0x560 drivers/char/misc.c:141 chrdev_open+0x25a/0x710 fs/char_dev.c:417 do_dentry_open+0x499/0x1250 fs/open.c:771 vfs_open+0xa0/0xd0 fs/open.c:880 do_last fs/namei.c:3418 [inline] path_openat+0x12bf/0x5160 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe SOFTIRQ-ON-W at: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] flush_bg_queue+0x389/0x650 fs/fuse/dev.c:364 fuse_request_send_background_locked+0x2f5/0x5a0 fs/fuse/dev.c:598 fuse_request_send_background+0x135/0x180 fs/fuse/dev.c:606 cuse_send_init fs/fuse/cuse.c:458 [inline] cuse_channel_open+0x6b0/0x963 fs/fuse/cuse.c:518 misc_open+0x3ca/0x560 drivers/char/misc.c:141 chrdev_open+0x25a/0x710 fs/char_dev.c:417 do_dentry_open+0x499/0x1250 fs/open.c:771 vfs_open+0xa0/0xd0 fs/open.c:880 do_last fs/namei.c:3418 [inline] path_openat+0x12bf/0x5160 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe INITIAL USE at: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] flush_bg_queue+0x389/0x650 fs/fuse/dev.c:364 fuse_request_send_background_locked+0x2f5/0x5a0 fs/fuse/dev.c:598 fuse_request_send_background+0x135/0x180 fs/fuse/dev.c:606 cuse_send_init fs/fuse/cuse.c:458 [inline] cuse_channel_open+0x6b0/0x963 fs/fuse/cuse.c:518 misc_open+0x3ca/0x560 drivers/char/misc.c:141 chrdev_open+0x25a/0x710 fs/char_dev.c:417 do_dentry_open+0x499/0x1250 fs/open.c:771 vfs_open+0xa0/0xd0 fs/open.c:880 do_last fs/namei.c:3418 [inline] path_openat+0x12bf/0x5160 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe } ... key at: [] __key.42168+0x0/0x40 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] aio_poll+0x760/0x1420 fs/aio.c:1747 io_submit_one+0xab8/0x1090 fs/aio.c:1850 __do_sys_io_submit fs/aio.c:1916 [inline] __se_sys_io_submit fs/aio.c:1887 [inline] __x64_sys_io_submit+0x1b9/0x5d0 fs/aio.c:1887 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> (&(&ctx->ctx_lock)->rlock){..-.} ops: 2 { IN-SOFTIRQ-W at: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x61/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] free_ioctx_users+0xbc/0x710 fs/aio.c:603 percpu_ref_put_many include/linux/percpu-refcount.h:284 [inline] percpu_ref_put include/linux/percpu-refcount.h:300 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline] percpu_ref_switch_to_atomic_rcu+0x62c/0x820 lib/percpu-refcount.c:158 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1056 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864 native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xbf/0x490 arch/x86/kernel/process.c:498 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3db/0x5b0 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 rest_init+0xe2/0xe5 init/main.c:442 start_kernel+0x8f4/0x92f init/main.c:739 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 INITIAL USE at: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x61/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] aio_poll+0x738/0x1420 fs/aio.c:1746 io_submit_one+0xab8/0x1090 fs/aio.c:1850 __do_sys_io_submit fs/aio.c:1916 [inline] __se_sys_io_submit fs/aio.c:1887 [inline] __x64_sys_io_submit+0x1b9/0x5d0 fs/aio.c:1887 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe } ... key at: [] __key.50120+0x0/0x40 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:2756 [inline] mark_lock+0xa6b/0x1cb0 kernel/locking/lockdep.c:3128 mark_irqflags kernel/locking/lockdep.c:3006 [inline] __lock_acquire+0x15f8/0x4ec0 kernel/locking/lockdep.c:3369 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x61/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] free_ioctx_users+0xbc/0x710 fs/aio.c:603 percpu_ref_put_many include/linux/percpu-refcount.h:284 [inline] percpu_ref_put include/linux/percpu-refcount.h:300 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline] percpu_ref_switch_to_atomic_rcu+0x62c/0x820 lib/percpu-refcount.c:158 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1056 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864 native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xbf/0x490 arch/x86/kernel/process.c:498 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3db/0x5b0 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 rest_init+0xe2/0xe5 init/main.c:442 start_kernel+0x8f4/0x92f init/main.c:739 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0-rc2+ #229 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113 print_irq_inversion_bug.part.35+0x2c7/0x2d6 kernel/locking/lockdep.c:2622 print_irq_inversion_bug kernel/locking/lockdep.c:2625 [inline] check_usage_forwards.cold.57+0x20/0x29 kernel/locking/lockdep.c:2647 mark_lock_irq kernel/locking/lockdep.c:2756 [inline] mark_lock+0xa6b/0x1cb0 kernel/locking/lockdep.c:3128 mark_irqflags kernel/locking/lockdep.c:3006 [inline] __lock_acquire+0x15f8/0x4ec0 kernel/locking/lockdep.c:3369 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x61/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] free_ioctx_users+0xbc/0x710 fs/aio.c:603 percpu_ref_put_many include/linux/percpu-refcount.h:284 [inline] percpu_ref_put include/linux/percpu-refcount.h:300 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline] percpu_ref_switch_to_atomic_rcu+0x62c/0x820 lib/percpu-refcount.c:158 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1056 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 Code: e9 2c ff ff ff 48 89 c7 48 89 45 d8 e8 43 b9 02 fa 48 8b 45 d8 e9 ca fe ff ff 48 89 df e8 32 b9 02 fa eb 82 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffffffff89407bb8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffffffff1280f7b RCX: 0000000000000000 RDX: 1ffffffff12a4538 RSI: 0000000000000001 RDI: ffffffff895229c0 RBP: ffffffff89407bb8 R08: ffffffff89475fc0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89407c78 R13: ffffffff8a3149a0 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xbf/0x490 arch/x86/kernel/process.c:498 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3db/0x5b0 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 rest_init+0xe2/0xe5 init/main.c:442 start_kernel+0x8f4/0x92f init/main.c:739 ? early_idt_handler_common+