===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.2.0-rc7 #12 Not tainted ----------------------------------------------------- syz-executor.0/7639 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: 00000000d78c3141 (&fiq->waitq){+.+.}, at: spin_lock include/linux/spinlock.h:338 [inline] 00000000d78c3141 (&fiq->waitq){+.+.}, at: aio_poll fs/aio.c:1752 [inline] 00000000d78c3141 (&fiq->waitq){+.+.}, at: __io_submit_one fs/aio.c:1826 [inline] 00000000d78c3141 (&fiq->waitq){+.+.}, at: io_submit_one+0x1167/0x1ac0 fs/aio.c:1863 and this task is already holding: 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline] 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1750 [inline] 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1826 [inline] 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0x1137/0x1ac0 fs/aio.c:1863 which would create a new lock dependency: (&(&ctx->ctx_lock)->rlock){..-.} -> (&fiq->waitq){+.+.} but this new dependency connects a SOFTIRQ-irq-safe lock: (&(&ctx->ctx_lock)->rlock){..-.} ... which became SOFTIRQ-irq-safe at: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x6a/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:363 [inline] free_ioctx_users+0x33/0x1d0 fs/aio.c:620 percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline] percpu_ref_put+0x1c6/0x1d0 include/linux/percpu-refcount.h:301 percpu_ref_call_confirm_rcu lib/percpu-refcount.c:124 [inline] percpu_ref_switch_to_atomic_rcu+0x260/0x310 lib/percpu-refcount.c:159 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0x8d6/0xf90 kernel/rcu/tree.c:2291 __do_softirq+0x340/0x7b0 arch/x86/include/asm/paravirt.h:777 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x21a/0x230 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0xf8/0x260 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call kernel/sched/idle.c:94 [inline] cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x18a/0x760 kernel/sched/idle.c:263 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:354 rest_init+0x29d/0x2b0 init/main.c:451 arch_call_rest_init+0xe/0x10 start_kernel+0x740/0x860 init/main.c:761 x86_64_start_reservations+0x18/0x2e arch/x86/kernel/head64.c:472 x86_64_start_kernel+0x7a/0x7d arch/x86/kernel/head64.c:453 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: ... __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] flush_bg_queue fs/fuse/dev.c:415 [inline] fuse_request_queue_background+0x655/0xc40 fs/fuse/dev.c:676 fuse_request_send_background+0x56/0xf0 fs/fuse/dev.c:687 cuse_send_init fs/fuse/cuse.c:459 [inline] cuse_channel_open+0x485/0x660 fs/fuse/cuse.c:519 misc_open+0x3ef/0x440 drivers/char/misc.c:141 chrdev_open+0x60a/0x670 fs/char_dev.c:413 do_dentry_open+0x7ba/0x1060 fs/open.c:778 vfs_open+0x73/0x80 fs/open.c:887 do_last fs/namei.c:3416 [inline] path_openat+0x136d/0x4400 fs/namei.c:3533 do_filp_open+0x1f7/0x430 fs/namei.c:3563 do_sys_open+0x343/0x620 fs/open.c:1070 __do_sys_openat fs/open.c:1097 [inline] __se_sys_openat fs/open.c:1091 [inline] __x64_sys_openat+0xa2/0xb0 fs/open.c:1091 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 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-executor.0/7639: #0: 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline] #0: 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1750 [inline] #0: 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1826 [inline] #0: 00000000175ee12d (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0x1137/0x1ac0 fs/aio.c:1863 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&(&ctx->ctx_lock)->rlock){..-.} { IN-SOFTIRQ-W at: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x6a/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:363 [inline] free_ioctx_users+0x33/0x1d0 fs/aio.c:620 percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline] percpu_ref_put+0x1c6/0x1d0 include/linux/percpu-refcount.h:301 percpu_ref_call_confirm_rcu lib/percpu-refcount.c:124 [inline] percpu_ref_switch_to_atomic_rcu+0x260/0x310 lib/percpu-refcount.c:159 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0x8d6/0xf90 kernel/rcu/tree.c:2291 __do_softirq+0x340/0x7b0 arch/x86/include/asm/paravirt.h:777 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x21a/0x230 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0xf8/0x260 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call kernel/sched/idle.c:94 [inline] cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x18a/0x760 kernel/sched/idle.c:263 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:354 rest_init+0x29d/0x2b0 init/main.c:451 arch_call_rest_init+0xe/0x10 start_kernel+0x740/0x860 init/main.c:761 x86_64_start_reservations+0x18/0x2e arch/x86/kernel/head64.c:472 x86_64_start_kernel+0x7a/0x7d arch/x86/kernel/head64.c:453 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 INITIAL USE at: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x6a/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:363 [inline] free_ioctx_users+0x33/0x1d0 fs/aio.c:620 percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline] percpu_ref_put+0x1c6/0x1d0 include/linux/percpu-refcount.h:301 percpu_ref_call_confirm_rcu lib/percpu-refcount.c:124 [inline] percpu_ref_switch_to_atomic_rcu+0x260/0x310 lib/percpu-refcount.c:159 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0x8d6/0xf90 kernel/rcu/tree.c:2291 __do_softirq+0x340/0x7b0 arch/x86/include/asm/paravirt.h:777 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x21a/0x230 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0xf8/0x260 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call kernel/sched/idle.c:94 [inline] cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x18a/0x760 kernel/sched/idle.c:263 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:354 rest_init+0x29d/0x2b0 init/main.c:451 arch_call_rest_init+0xe/0x10 start_kernel+0x740/0x860 init/main.c:761 x86_64_start_reservations+0x18/0x2e arch/x86/kernel/head64.c:472 x86_64_start_kernel+0x7a/0x7d arch/x86/kernel/head64.c:453 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 } ... key at: [] ioctx_alloc.__key+0x0/0x10 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] aio_poll fs/aio.c:1752 [inline] __io_submit_one fs/aio.c:1826 [inline] io_submit_one+0x1167/0x1ac0 fs/aio.c:1863 __do_sys_io_submit fs/aio.c:1922 [inline] __se_sys_io_submit+0x18f/0x2d0 fs/aio.c:1892 __x64_sys_io_submit+0x7b/0x90 fs/aio.c:1892 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 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: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] flush_bg_queue fs/fuse/dev.c:415 [inline] fuse_request_queue_background+0x655/0xc40 fs/fuse/dev.c:676 fuse_request_send_background+0x56/0xf0 fs/fuse/dev.c:687 cuse_send_init fs/fuse/cuse.c:459 [inline] cuse_channel_open+0x485/0x660 fs/fuse/cuse.c:519 misc_open+0x3ef/0x440 drivers/char/misc.c:141 chrdev_open+0x60a/0x670 fs/char_dev.c:413 do_dentry_open+0x7ba/0x1060 fs/open.c:778 vfs_open+0x73/0x80 fs/open.c:887 do_last fs/namei.c:3416 [inline] path_openat+0x136d/0x4400 fs/namei.c:3533 do_filp_open+0x1f7/0x430 fs/namei.c:3563 do_sys_open+0x343/0x620 fs/open.c:1070 __do_sys_openat fs/open.c:1097 [inline] __se_sys_openat fs/open.c:1091 [inline] __x64_sys_openat+0xa2/0xb0 fs/open.c:1091 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe SOFTIRQ-ON-W at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] flush_bg_queue fs/fuse/dev.c:415 [inline] fuse_request_queue_background+0x655/0xc40 fs/fuse/dev.c:676 fuse_request_send_background+0x56/0xf0 fs/fuse/dev.c:687 cuse_send_init fs/fuse/cuse.c:459 [inline] cuse_channel_open+0x485/0x660 fs/fuse/cuse.c:519 misc_open+0x3ef/0x440 drivers/char/misc.c:141 chrdev_open+0x60a/0x670 fs/char_dev.c:413 do_dentry_open+0x7ba/0x1060 fs/open.c:778 vfs_open+0x73/0x80 fs/open.c:887 do_last fs/namei.c:3416 [inline] path_openat+0x136d/0x4400 fs/namei.c:3533 do_filp_open+0x1f7/0x430 fs/namei.c:3563 do_sys_open+0x343/0x620 fs/open.c:1070 __do_sys_openat fs/open.c:1097 [inline] __se_sys_openat fs/open.c:1091 [inline] __x64_sys_openat+0xa2/0xb0 fs/open.c:1091 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe INITIAL USE at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] flush_bg_queue fs/fuse/dev.c:415 [inline] fuse_request_queue_background+0x655/0xc40 fs/fuse/dev.c:676 fuse_request_send_background+0x56/0xf0 fs/fuse/dev.c:687 cuse_send_init fs/fuse/cuse.c:459 [inline] cuse_channel_open+0x485/0x660 fs/fuse/cuse.c:519 misc_open+0x3ef/0x440 drivers/char/misc.c:141 chrdev_open+0x60a/0x670 fs/char_dev.c:413 do_dentry_open+0x7ba/0x1060 fs/open.c:778 vfs_open+0x73/0x80 fs/open.c:887 do_last fs/namei.c:3416 [inline] path_openat+0x136d/0x4400 fs/namei.c:3533 do_filp_open+0x1f7/0x430 fs/namei.c:3563 do_sys_open+0x343/0x620 fs/open.c:1070 __do_sys_openat fs/open.c:1097 [inline] __se_sys_openat fs/open.c:1091 [inline] __x64_sys_openat+0xa2/0xb0 fs/open.c:1091 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe } ... key at: [] fuse_iqueue_init.__key+0x0/0x10 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] aio_poll fs/aio.c:1752 [inline] __io_submit_one fs/aio.c:1826 [inline] io_submit_one+0x1167/0x1ac0 fs/aio.c:1863 __do_sys_io_submit fs/aio.c:1922 [inline] __se_sys_io_submit+0x18f/0x2d0 fs/aio.c:1892 __x64_sys_io_submit+0x7b/0x90 fs/aio.c:1892 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe stack backtrace: CPU: 0 PID: 7639 Comm: syz-executor.0 Not tainted 5.2.0-rc7 #12 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+0x1d8/0x2f8 lib/dump_stack.c:113 print_bad_irq_dependency kernel/locking/lockdep.c:1920 [inline] check_irq_usage kernel/locking/lockdep.c:2114 [inline] check_prev_add kernel/locking/lockdep.c:2315 [inline] check_prevs_add kernel/locking/lockdep.c:2418 [inline] validate_chain+0x829b/0x84f0 kernel/locking/lockdep.c:2800 __lock_acquire+0xcf7/0x1a40 kernel/locking/lockdep.c:3793 lock_acquire+0x158/0x250 kernel/locking/lockdep.c:4303 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] aio_poll fs/aio.c:1752 [inline] __io_submit_one fs/aio.c:1826 [inline] io_submit_one+0x1167/0x1ac0 fs/aio.c:1863 __do_sys_io_submit fs/aio.c:1922 [inline] __se_sys_io_submit+0x18f/0x2d0 fs/aio.c:1892 __x64_sys_io_submit+0x7b/0x90 fs/aio.c:1892 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4597c9 Code: fd 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f33ca4aac78 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004597c9 RDX: 0000000020000200 RSI: 0000000000000001 RDI: 00007f33ca48a000 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f33ca4ab6d4 R13: 00000000004c0b97 R14: 00000000004d3908 R15: 00000000ffffffff