======================================================== WARNING: possible irq lock inversion dependency detected 5.2.0-rc6+ #7 Not tainted -------------------------------------------------------- syz-executor211/8083 just changed the state of lock: 00000000df76c770 (&ctx->fault_pending_wqh){+.+.}, at: spin_lock include/linux/spinlock.h:338 [inline] 00000000df76c770 (&ctx->fault_pending_wqh){+.+.}, at: userfaultfd_release+0x4dc/0x620 fs/userfaultfd.c:921 but this lock was taken by another, SOFTIRQ-safe lock in the past: (&(&ctx->ctx_lock)->rlock){..-.} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Chain exists of: &(&ctx->ctx_lock)->rlock --> &ctx->fd_wqh --> &ctx->fault_pending_wqh Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctx->fault_pending_wqh); local_irq_disable(); lock(&(&ctx->ctx_lock)->rlock); lock(&ctx->fd_wqh); lock(&(&ctx->ctx_lock)->rlock); *** DEADLOCK *** no locks held by syz-executor211/8083. the shortest dependencies between 2nd lock and 1st 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 start_secondary+0x425/0x4c0 arch/x86/kernel/smpboot.c:265 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] aio_poll fs/aio.c:1750 [inline] __io_submit_one fs/aio.c:1826 [inline] io_submit_one+0x1137/0x1ac0 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 } ... 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 -> (&ctx->fd_wqh){....} { INITIAL USE at: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa1/0xc0 kernel/locking/spinlock.c:159 add_wait_queue+0x41/0x150 kernel/sched/wait.c:23 aio_poll_queue_proc+0xdf/0x160 fs/aio.c:1715 poll_wait include/linux/poll.h:51 [inline] userfaultfd_poll+0x84/0x1d0 fs/userfaultfd.c:970 vfs_poll include/linux/poll.h:90 [inline] aio_poll fs/aio.c:1749 [inline] __io_submit_one fs/aio.c:1826 [inline] io_submit_one+0x1102/0x1ac0 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 } ... key at: [] init_once_userfaultfd_ctx.__key.15+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] userfaultfd_ctx_read+0x3e7/0x1430 fs/userfaultfd.c:1045 userfaultfd_read+0x15d/0x2b0 fs/userfaultfd.c:1203 __vfs_read+0xf9/0x7c0 fs/read_write.c:425 vfs_read+0x195/0x3c0 fs/read_write.c:461 ksys_read+0x16b/0x2a0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:595 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> (&ctx->fault_pending_wqh){+.+.} { 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] userfaultfd_release+0x4dc/0x620 fs/userfaultfd.c:921 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x63f/0x2300 kernel/exit.c:877 do_group_exit+0x15c/0x2a0 kernel/exit.c:981 get_signal+0x6df/0x21f0 kernel/signal.c:2640 do_signal+0x7b/0x750 arch/x86/kernel/signal.c:815 exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] prepare_exit_to_usermode+0x2f5/0x4f0 arch/x86/entry/common.c:199 syscall_return_slowpath+0x110/0x440 arch/x86/entry/common.c:279 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:304 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] userfaultfd_release+0x4dc/0x620 fs/userfaultfd.c:921 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x63f/0x2300 kernel/exit.c:877 do_group_exit+0x15c/0x2a0 kernel/exit.c:981 get_signal+0x6df/0x21f0 kernel/signal.c:2640 do_signal+0x7b/0x750 arch/x86/kernel/signal.c:815 exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] prepare_exit_to_usermode+0x2f5/0x4f0 arch/x86/entry/common.c:199 syscall_return_slowpath+0x110/0x440 arch/x86/entry/common.c:279 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:304 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] userfaultfd_ctx_read+0x3e7/0x1430 fs/userfaultfd.c:1045 userfaultfd_read+0x15d/0x2b0 fs/userfaultfd.c:1203 __vfs_read+0xf9/0x7c0 fs/read_write.c:425 vfs_read+0x195/0x3c0 fs/read_write.c:461 ksys_read+0x16b/0x2a0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:595 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe } ... key at: [] init_once_userfaultfd_ctx.__key+0x0/0x10 ... acquired at: mark_irqflags kernel/locking/lockdep.c:3409 [inline] __lock_acquire+0x60b/0x1a40 kernel/locking/lockdep.c:3745 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] userfaultfd_release+0x4dc/0x620 fs/userfaultfd.c:921 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x63f/0x2300 kernel/exit.c:877 do_group_exit+0x15c/0x2a0 kernel/exit.c:981 get_signal+0x6df/0x21f0 kernel/signal.c:2640 do_signal+0x7b/0x750 arch/x86/kernel/signal.c:815 exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] prepare_exit_to_usermode+0x2f5/0x4f0 arch/x86/entry/common.c:199 syscall_return_slowpath+0x110/0x440 arch/x86/entry/common.c:279 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe stack backtrace: CPU: 0 PID: 8083 Comm: syz-executor211 Not tainted 5.2.0-rc6+ #7 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_irq_inversion_bug+0xa59/0xd00 kernel/locking/lockdep.c:3011 check_usage_backwards+0x1ac/0x300 kernel/locking/lockdep.c:3061 mark_lock_irq kernel/locking/lockdep.c:3146 [inline] mark_lock+0x498/0x1660 kernel/locking/lockdep.c:3513 mark_irqflags kernel/locking/lockdep.c:3409 [inline] __lock_acquire+0x60b/0x1a40 kernel/locking/lockdep.c:3745 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] userfaultfd_release+0x4dc/0x620 fs/userfaultfd.c:921 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x63f/0x2300 kernel/exit.c:877 do_group_exit+0x15c/0x2a0 kernel/exit.c:981 get_signal+0x6df/0x21f0 kernel/signal.c:2640 do_signal+0x7b/0x750 arch/x86/kernel/signal.c:815 exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] prepare_exit_to_usermode+0x2f5/0x4f0 arch/x86/entry/common.c:199 syscall_return_slowpath+0x110/0x440 arch/x86/entry/common.c:279 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4413a9 Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffb598eb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 00000000004413a9 RDX: 0000000000000064 RSI: 0000000020009f9c RDI: 0000000000000005 RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000402120 R13: 00000000004021b0 R14: 0000000000000000 R15: 0000000000000000