=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.2.0-rc6-next-20190626 #23 Not tainted
-----------------------------------------------------
syz-executor.0/9201 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
0000000064092eda (&ctx->fd_wqh){....}, at: spin_lock include/linux/spinlock.h:338 [inline]
0000000064092eda (&ctx->fd_wqh){....}, at: aio_poll fs/aio.c:1749 [inline]
0000000064092eda (&ctx->fd_wqh){....}, at: __io_submit_one fs/aio.c:1823 [inline]
0000000064092eda (&ctx->fd_wqh){....}, at: io_submit_one+0xefa/0x2ef0 fs/aio.c:1860
and this task is already holding:
0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline]
0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1747 [inline]
0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1823 [inline]
0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb5/0x2ef0 fs/aio.c:1860
which would create a new lock dependency:
(&(&ctx->ctx_lock)->rlock){..-.} -> (&ctx->fd_wqh){....}
but this new dependency connects a SOFTIRQ-irq-safe lock:
(&(&ctx->ctx_lock)->rlock){..-.}
... which became SOFTIRQ-irq-safe at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167
spin_lock_irq include/linux/spinlock.h:363 [inline]
free_ioctx_users+0x2d/0x490 fs/aio.c:620
percpu_ref_put_many include/linux/percpu-refcount.h:293 [inline]
percpu_ref_put include/linux/percpu-refcount.h:309 [inline]
percpu_ref_call_confirm_rcu lib/percpu-refcount.c:130 [inline]
percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 lib/percpu-refcount.c:165
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch kernel/rcu/tree.c:2114 [inline]
rcu_core+0x67f/0x1580 kernel/rcu/tree.c:2314
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2323
__do_softirq+0x262/0x98c kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x19b/0x1e0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:535 [inline]
smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1068
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
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+0x84/0xb0 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x413/0x760 kernel/sched/idle.c:263
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
start_secondary+0x3fe/0x580 arch/x86/kernel/smpboot.c:276
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
to a SOFTIRQ-irq-unsafe lock:
(&ctx->fault_pending_wqh){+.+.}
... which became SOFTIRQ-irq-unsafe at:
...
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
userfaultfd_release+0x4ca/0x710 fs/userfaultfd.c:921
__fput+0x2ff/0x890 fs/file_table.c:280
____fput+0x16/0x20 fs/file_table.c:313
task_work_run+0x145/0x1c0 kernel/task_work.c:113
get_signal+0x2078/0x2500 kernel/signal.c:2522
do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x251/0x2d0 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
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);
<Interrupt>
lock(&(&ctx->ctx_lock)->rlock);
*** DEADLOCK ***
1 lock held by syz-executor.0/9201:
#0: 0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline]
#0: 0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1747 [inline]
#0: 0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1823 [inline]
#0: 0000000035d5b187 (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb5/0x2ef0 fs/aio.c:1860
the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&(&ctx->ctx_lock)->rlock){..-.} {
IN-SOFTIRQ-W at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167
spin_lock_irq include/linux/spinlock.h:363 [inline]
free_ioctx_users+0x2d/0x490 fs/aio.c:620
percpu_ref_put_many include/linux/percpu-refcount.h:293 [inline]
percpu_ref_put include/linux/percpu-refcount.h:309 [inline]
percpu_ref_call_confirm_rcu lib/percpu-refcount.c:130 [inline]
percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 lib/percpu-refcount.c:165
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch kernel/rcu/tree.c:2114 [inline]
rcu_core+0x67f/0x1580 kernel/rcu/tree.c:2314
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2323
__do_softirq+0x262/0x98c kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x19b/0x1e0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:535 [inline]
smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1068
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
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+0x84/0xb0 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x413/0x760 kernel/sched/idle.c:263
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
start_secondary+0x3fe/0x580 arch/x86/kernel/smpboot.c:276
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
INITIAL USE at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167
spin_lock_irq include/linux/spinlock.h:363 [inline]
free_ioctx_users+0x2d/0x490 fs/aio.c:620
percpu_ref_put_many include/linux/percpu-refcount.h:293 [inline]
percpu_ref_put include/linux/percpu-refcount.h:309 [inline]
percpu_ref_call_confirm_rcu lib/percpu-refcount.c:130 [inline]
percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 lib/percpu-refcount.c:165
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch kernel/rcu/tree.c:2114 [inline]
rcu_core+0x67f/0x1580 kernel/rcu/tree.c:2314
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2323
__do_softirq+0x262/0x98c kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x19b/0x1e0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:535 [inline]
smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1068
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
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+0x84/0xb0 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x413/0x760 kernel/sched/idle.c:263
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
start_secondary+0x3fe/0x580 arch/x86/kernel/smpboot.c:276
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
}
... key at: [<ffffffff8a8a8360>] __key.53807+0x0/0x40
... acquired at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
aio_poll fs/aio.c:1749 [inline]
__io_submit_one fs/aio.c:1823 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1860
__do_sys_io_submit fs/aio.c:1919 [inline]
__se_sys_io_submit fs/aio.c:1889 [inline]
__x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1889
do_syscall_64+0xfd/0x6a0 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:
-> (&ctx->fault_pending_wqh){+.+.} {
HARDIRQ-ON-W at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
userfaultfd_release+0x4ca/0x710 fs/userfaultfd.c:921
__fput+0x2ff/0x890 fs/file_table.c:280
____fput+0x16/0x20 fs/file_table.c:313
task_work_run+0x145/0x1c0 kernel/task_work.c:113
get_signal+0x2078/0x2500 kernel/signal.c:2522
do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x251/0x2d0 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
SOFTIRQ-ON-W at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
userfaultfd_release+0x4ca/0x710 fs/userfaultfd.c:921
__fput+0x2ff/0x890 fs/file_table.c:280
____fput+0x16/0x20 fs/file_table.c:313
task_work_run+0x145/0x1c0 kernel/task_work.c:113
get_signal+0x2078/0x2500 kernel/signal.c:2522
do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x251/0x2d0 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
INITIAL USE at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
userfaultfd_ctx_read fs/userfaultfd.c:1045 [inline]
userfaultfd_read+0x54d/0x1940 fs/userfaultfd.c:1203
__vfs_read+0x8a/0x110 fs/read_write.c:425
vfs_read+0x1f0/0x440 fs/read_write.c:461
ksys_read+0x14f/0x290 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+0x73/0xb0 fs/read_write.c:595
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8a8a81a0>] __key.46524+0x0/0x40
... acquired at:
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
userfaultfd_ctx_read fs/userfaultfd.c:1045 [inline]
userfaultfd_read+0x54d/0x1940 fs/userfaultfd.c:1203
__vfs_read+0x8a/0x110 fs/read_write.c:425
vfs_read+0x1f0/0x440 fs/read_write.c:461
ksys_read+0x14f/0x290 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+0x73/0xb0 fs/read_write.c:595
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> (&ctx->fd_wqh){....} {
INITIAL USE at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167
spin_lock_irq include/linux/spinlock.h:363 [inline]
userfaultfd_ctx_read fs/userfaultfd.c:1041 [inline]
userfaultfd_read+0x27a/0x1940 fs/userfaultfd.c:1203
__vfs_read+0x8a/0x110 fs/read_write.c:425
vfs_read+0x1f0/0x440 fs/read_write.c:461
ksys_read+0x14f/0x290 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+0x73/0xb0 fs/read_write.c:595
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8a8a80e0>] __key.46527+0x0/0x40
... acquired at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
aio_poll fs/aio.c:1749 [inline]
__io_submit_one fs/aio.c:1823 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1860
__do_sys_io_submit fs/aio.c:1919 [inline]
__se_sys_io_submit fs/aio.c:1889 [inline]
__x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1889
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x49/0xbe
stack backtrace:
CPU: 1 PID: 9201 Comm: syz-executor.0 Not tainted 5.2.0-rc6-next-20190626 #23
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+0x172/0x1f0 lib/dump_stack.c:113
print_bad_irq_dependency kernel/locking/lockdep.c:2025 [inline]
check_irq_usage.cold+0x5b4/0x72e kernel/locking/lockdep.c:2223
check_prev_add kernel/locking/lockdep.c:2409 [inline]
check_prevs_add kernel/locking/lockdep.c:2507 [inline]
validate_chain kernel/locking/lockdep.c:2897 [inline]
__lock_acquire+0x25bd/0x4c20 kernel/locking/lockdep.c:3880
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4413
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
aio_poll fs/aio.c:1749 [inline]
__io_submit_one fs/aio.c:1823 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1860
__do_sys_io_submit fs/aio.c:1919 [inline]
__se_sys_io_submit fs/aio.c:1889 [inline]
__x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1889
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459519
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:00007f95ed61fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459519
RDX: 0000000020000600 RSI: 0000000000000001 RDI: 00007f95ed621000
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f95ed6206d4
R13: 00000000004c0898 R14: 00000000004d3548 R15: 00000000ffffffff