kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.0.0-rc4+ #50 Not tainted ----------------------------------------------------- kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env syz-executor3/20254 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: 0000000019a9d17c (&fiq->waitq){+.+.}, at: spin_lock include/linux/spinlock.h:329 [inline] 0000000019a9d17c (&fiq->waitq){+.+.}, at: aio_poll+0x7b9/0x14e0 fs/aio.c:1772 and this task is already holding: kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' 0000000011d2088d (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline] 0000000011d2088d (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll+0x790/0x14e0 fs/aio.c:1771 which would create a new lock dependency: (&(&ctx->ctx_lock)->rlock){..-.} -> (&fiq->waitq){+.+.} kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' but this new dependency connects a SOFTIRQ-irq-safe lock: (&(&ctx->ctx_lock)->rlock){..-.} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] free_ioctx_users+0xa7/0x6e0 fs/aio.c:610 kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline] percpu_ref_put include/linux/percpu-refcount.h:301 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline] percpu_ref_switch_to_atomic_rcu+0x50c/0x6b0 lib/percpu-refcount.c:158 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0xc4a/0x1680 kernel/rcu/tree.c:2754 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x386/0x5d0 kernel/sched/idle.c:262 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353 start_secondary+0x435/0x620 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 to a SOFTIRQ-irq-unsafe lock: (&fiq->waitq){+.+.} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] flush_bg_queue+0x28c/0x570 fs/fuse/dev.c:413 fuse_request_queue_background+0x360/0x640 fs/fuse/dev.c:652 fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:663 fuse_send_init fs/fuse/inode.c:984 [inline] fuse_fill_super+0x1b05/0x1f30 fs/fuse/inode.c:1210 mount_nodev+0x68/0x110 fs/super.c:1205 fuse_mount+0x2d/0x40 fs/fuse/inode.c:1235 mount_fs+0x123/0x43a fs/super.c:1258 vfs_kern_mount.part.0+0xdb/0x570 fs/namespace.c:959 vfs_kern_mount fs/namespace.c:949 [inline] do_new_mount fs/namespace.c:2513 [inline] do_mount+0x58e/0x3330 fs/namespace.c:2847 ksys_mount+0xdb/0x150 fs/namespace.c:3063 __do_sys_mount fs/namespace.c:3077 [inline] __se_sys_mount fs/namespace.c:3074 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3074 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe 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 *** 1 lock held by syz-executor3/20254: #0: 0000000011d2088d (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline] #0: 0000000011d2088d (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll+0x790/0x14e0 fs/aio.c:1771 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&(&ctx->ctx_lock)->rlock){..-.} { IN-SOFTIRQ-W at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] free_ioctx_users+0xa7/0x6e0 fs/aio.c:610 percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline] percpu_ref_put include/linux/percpu-refcount.h:301 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline] percpu_ref_switch_to_atomic_rcu+0x50c/0x6b0 lib/percpu-refcount.c:158 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0xc4a/0x1680 kernel/rcu/tree.c:2754 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x386/0x5d0 kernel/sched/idle.c:262 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353 start_secondary+0x435/0x620 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 INITIAL USE at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] free_ioctx_users+0xa7/0x6e0 fs/aio.c:610 percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline] percpu_ref_put include/linux/percpu-refcount.h:301 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline] percpu_ref_switch_to_atomic_rcu+0x50c/0x6b0 lib/percpu-refcount.c:158 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0xc4a/0x1680 kernel/rcu/tree.c:2754 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x386/0x5d0 kernel/sched/idle.c:262 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353 start_secondary+0x435/0x620 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 } ... key at: [] __key.51971+0x0/0x40 ... acquired at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] aio_poll+0x7b9/0x14e0 fs/aio.c:1772 __io_submit_one fs/aio.c:1875 [inline] io_submit_one+0xc39/0x1050 fs/aio.c:1908 __do_sys_io_submit fs/aio.c:1953 [inline] __se_sys_io_submit fs/aio.c:1923 [inline] __x64_sys_io_submit+0x1c4/0x5d0 fs/aio.c:1923 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (&fiq->waitq){+.+.} { HARDIRQ-ON-W at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] flush_bg_queue+0x28c/0x570 fs/fuse/dev.c:413 fuse_request_queue_background+0x360/0x640 fs/fuse/dev.c:652 fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:663 fuse_send_init fs/fuse/inode.c:984 [inline] fuse_fill_super+0x1b05/0x1f30 fs/fuse/inode.c:1210 mount_nodev+0x68/0x110 fs/super.c:1205 fuse_mount+0x2d/0x40 fs/fuse/inode.c:1235 mount_fs+0x123/0x43a fs/super.c:1258 vfs_kern_mount.part.0+0xdb/0x570 fs/namespace.c:959 vfs_kern_mount fs/namespace.c:949 [inline] do_new_mount fs/namespace.c:2513 [inline] do_mount+0x58e/0x3330 fs/namespace.c:2847 ksys_mount+0xdb/0x150 fs/namespace.c:3063 __do_sys_mount fs/namespace.c:3077 [inline] __se_sys_mount fs/namespace.c:3074 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3074 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe SOFTIRQ-ON-W at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] flush_bg_queue+0x28c/0x570 fs/fuse/dev.c:413 fuse_request_queue_background+0x360/0x640 fs/fuse/dev.c:652 fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:663 fuse_send_init fs/fuse/inode.c:984 [inline] fuse_fill_super+0x1b05/0x1f30 fs/fuse/inode.c:1210 mount_nodev+0x68/0x110 fs/super.c:1205 fuse_mount+0x2d/0x40 fs/fuse/inode.c:1235 mount_fs+0x123/0x43a fs/super.c:1258 vfs_kern_mount.part.0+0xdb/0x570 fs/namespace.c:959 vfs_kern_mount fs/namespace.c:949 [inline] do_new_mount fs/namespace.c:2513 [inline] do_mount+0x58e/0x3330 fs/namespace.c:2847 ksys_mount+0xdb/0x150 fs/namespace.c:3063 __do_sys_mount fs/namespace.c:3077 [inline] __se_sys_mount fs/namespace.c:3074 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3074 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe INITIAL USE at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] flush_bg_queue+0x28c/0x570 fs/fuse/dev.c:413 fuse_request_queue_background+0x360/0x640 fs/fuse/dev.c:652 fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:663 fuse_send_init fs/fuse/inode.c:984 [inline] fuse_fill_super+0x1b05/0x1f30 fs/fuse/inode.c:1210 mount_nodev+0x68/0x110 fs/super.c:1205 fuse_mount+0x2d/0x40 fs/fuse/inode.c:1235 mount_fs+0x123/0x43a fs/super.c:1258 vfs_kern_mount.part.0+0xdb/0x570 fs/namespace.c:959 vfs_kern_mount fs/namespace.c:949 [inline] do_new_mount fs/namespace.c:2513 [inline] do_mount+0x58e/0x3330 fs/namespace.c:2847 ksys_mount+0xdb/0x150 fs/namespace.c:3063 __do_sys_mount fs/namespace.c:3077 [inline] __se_sys_mount fs/namespace.c:3074 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3074 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe } ... key at: [] __key.43074+0x0/0x40 ... acquired at: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] aio_poll+0x7b9/0x14e0 fs/aio.c:1772 __io_submit_one fs/aio.c:1875 [inline] io_submit_one+0xc39/0x1050 fs/aio.c:1908 __do_sys_io_submit fs/aio.c:1953 [inline] __se_sys_io_submit fs/aio.c:1923 [inline] __x64_sys_io_submit+0x1c4/0x5d0 fs/aio.c:1923 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe stack backtrace: CPU: 0 PID: 20254 Comm: syz-executor3 Not tainted 5.0.0-rc4+ #50 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+0x1db/0x2d0 lib/dump_stack.c:113 print_bad_irq_dependency kernel/locking/lockdep.c:1573 [inline] check_usage.cold+0x5e2/0x917 kernel/locking/lockdep.c:1605 check_irq_usage kernel/locking/lockdep.c:1661 [inline] check_prev_add_irq kernel/locking/lockdep_states.h:8 [inline] check_prev_add kernel/locking/lockdep.c:1871 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2350 [inline] __lock_acquire+0x2169/0x4a30 kernel/locking/lockdep.c:3338 lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] aio_poll+0x7b9/0x14e0 fs/aio.c:1772 __io_submit_one fs/aio.c:1875 [inline] io_submit_one+0xc39/0x1050 fs/aio.c:1908 __do_sys_io_submit fs/aio.c:1953 [inline] __se_sys_io_submit fs/aio.c:1923 [inline] __x64_sys_io_submit+0x1c4/0x5d0 fs/aio.c:1923 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458089 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc926456c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458089 RDX: 00000000200004c0 RSI: 0000000000000001 RDI: 00007fc926436000 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc9264576d4 R13: 00000000004bf2ab R14: 00000000004d0ad8 R15: 00000000ffffffff kobject: 'loop1' (00000000d64c4d9b): kobject_uevent_env kobject: 'loop1' (00000000d64c4d9b): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: 'loop4' (00000000ef675eff): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: '0:45' (000000000233b26b): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: 'loop4' (00000000ef675eff): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: '0:45' (000000000233b26b): kobject_uevent_env kobject: 'loop0' (00000000d3d7bb5b): kobject_uevent_env kobject: '0:45' (000000000233b26b): fill_kobj_path: path = '/devices/virtual/bdi/0:45' kobject: 'loop0' (00000000d3d7bb5b): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop2' (00000000c543e4f5): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: '0:45' (000000000233b26b): kobject_uevent_env kobject: '0:45' (000000000233b26b): fill_kobj_path: path = '/devices/virtual/bdi/0:45' kobject: 'loop2' (00000000c543e4f5): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: '0:45' (000000000233b26b): kobject_cleanup, parent (null) kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: '0:45' (000000000233b26b): calling ktype release kobject: 'loop1' (00000000d64c4d9b): kobject_uevent_env kobject: '0:45': free name kobject: 'loop1' (00000000d64c4d9b): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: 'loop5' (00000000c85f13e5): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'loop5' (00000000c85f13e5): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): kobject_uevent_env kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (00000000c9f0deea): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'loop1' (00000000d64c4d9b): kobject_uevent_env kobject: 'loop1' (00000000d64c4d9b): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (00000000d3d7bb5b): kobject_uevent_env kobject: 'loop0' (00000000d3d7bb5b): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop4' (00000000ef675eff): kobject_uevent_env kobject: 'loop4' (00000000ef675eff): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (00000000c543e4f5): kobject_uevent_env kobject: 'loop2' (00000000c543e4f5): fill_kobj_path: path = '/devices/virtual/block/loop2'