=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.2.0-rc6+ #37 Not tainted
-----------------------------------------------------
syz-executor.0/8843 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
000000008ea7bc65 (&ctx->fd_wqh){....}, at: spin_lock include/linux/spinlock.h:338 [inline]
000000008ea7bc65 (&ctx->fd_wqh){....}, at: aio_poll fs/aio.c:1752 [inline]
000000008ea7bc65 (&ctx->fd_wqh){....}, at: __io_submit_one fs/aio.c:1826 [inline]
000000008ea7bc65 (&ctx->fd_wqh){....}, at: io_submit_one+0xefa/0x2ef0 fs/aio.c:1863
and this task is already holding:
000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline]
000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1750 [inline]
000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1826 [inline]
000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb5/0x2ef0 fs/aio.c:1863
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+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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:285 [inline]
percpu_ref_put include/linux/percpu-refcount.h:301 [inline]
percpu_ref_call_confirm_rcu lib/percpu-refcount.c:124 [inline]
percpu_ref_switch_to_atomic_rcu+0x407/0x540 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+0xba5/0x1500 kernel/rcu/tree.c:2291
__do_softirq+0x25c/0x94c 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+0x13b/0x550 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+0x36/0x90 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x377/0x560 kernel/sched/idle.c:263
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
rest_init+0x245/0x37b init/main.c:451
arch_call_rest_init+0xe/0x1b
start_kernel+0x854/0x893 init/main.c:761
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451
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+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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+0x201b/0x24b0 kernel/signal.c:2434
do_signal+0x87/0x1900 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x244/0x2c0 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_32_irqs_on arch/x86/entry/common.c:352 [inline]
do_fast_syscall_32+0xb51/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
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.0/8843:
#0: 000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline]
#0: 000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1750 [inline]
#0: 000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1826 [inline]
#0: 000000008b88f602 (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb5/0x2ef0 fs/aio.c:1863
the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&(&ctx->ctx_lock)->rlock){..-.} {
IN-SOFTIRQ-W at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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:285 [inline]
percpu_ref_put include/linux/percpu-refcount.h:301 [inline]
percpu_ref_call_confirm_rcu lib/percpu-refcount.c:124 [inline]
percpu_ref_switch_to_atomic_rcu+0x407/0x540 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+0xba5/0x1500 kernel/rcu/tree.c:2291
__do_softirq+0x25c/0x94c 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+0x13b/0x550 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+0x36/0x90 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x377/0x560 kernel/sched/idle.c:263
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
rest_init+0x245/0x37b init/main.c:451
arch_call_rest_init+0xe/0x1b
start_kernel+0x854/0x893 init/main.c:761
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
INITIAL USE at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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:285 [inline]
percpu_ref_put include/linux/percpu-refcount.h:301 [inline]
percpu_ref_call_confirm_rcu lib/percpu-refcount.c:124 [inline]
percpu_ref_switch_to_atomic_rcu+0x407/0x540 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+0xba5/0x1500 kernel/rcu/tree.c:2291
__do_softirq+0x25c/0x94c 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+0x13b/0x550 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+0x36/0x90 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x377/0x560 kernel/sched/idle.c:263
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
rest_init+0x245/0x37b init/main.c:451
arch_call_rest_init+0xe/0x1b
start_kernel+0x854/0x893 init/main.c:761
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
}
... key at: [<ffffffff8a67b220>] __key.53436+0x0/0x40
... acquired at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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:1752 [inline]
__io_submit_one fs/aio.c:1826 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1863
__do_compat_sys_io_submit fs/aio.c:1964 [inline]
__se_compat_sys_io_submit fs/aio.c:1934 [inline]
__ia32_compat_sys_io_submit+0x1bf/0x570 fs/aio.c:1934
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
the dependencies between the lock to be acquired
and SOFTIRQ-irq-unsafe lock:
-> (&ctx->fault_pending_wqh){+.+.} {
HARDIRQ-ON-W at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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+0x201b/0x24b0 kernel/signal.c:2434
do_signal+0x87/0x1900 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x244/0x2c0 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_32_irqs_on arch/x86/entry/common.c:352 [inline]
do_fast_syscall_32+0xb51/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
SOFTIRQ-ON-W at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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+0x201b/0x24b0 kernel/signal.c:2434
do_signal+0x87/0x1900 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x244/0x2c0 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_32_irqs_on arch/x86/entry/common.c:352 [inline]
do_fast_syscall_32+0xb51/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
INITIAL USE at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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+0x540/0x1940 fs/userfaultfd.c:1203
__vfs_read+0x8a/0x110 fs/read_write.c:425
vfs_read+0x194/0x3e0 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]
__ia32_sys_read+0x71/0xb0 fs/read_write.c:595
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
}
... key at: [<ffffffff8a67b060>] __key.46109+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+0x540/0x1940 fs/userfaultfd.c:1203
__vfs_read+0x8a/0x110 fs/read_write.c:425
vfs_read+0x194/0x3e0 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]
__ia32_sys_read+0x71/0xb0 fs/read_write.c:595
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
-> (&ctx->fd_wqh){....} {
INITIAL USE at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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+0x194/0x3e0 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]
__ia32_sys_read+0x71/0xb0 fs/read_write.c:595
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
}
... key at: [<ffffffff8a67afa0>] __key.46112+0x0/0x40
... acquired at:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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:1752 [inline]
__io_submit_one fs/aio.c:1826 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1863
__do_compat_sys_io_submit fs/aio.c:1964 [inline]
__se_compat_sys_io_submit fs/aio.c:1934 [inline]
__ia32_compat_sys_io_submit+0x1bf/0x570 fs/aio.c:1934
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
stack backtrace:
CPU: 1 PID: 8843 Comm: syz-executor.0 Not tainted 5.2.0-rc6+ #37
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:1920 [inline]
check_irq_usage.cold+0x711/0xba0 kernel/locking/lockdep.c:2114
check_prev_add kernel/locking/lockdep.c:2315 [inline]
check_prevs_add kernel/locking/lockdep.c:2418 [inline]
validate_chain kernel/locking/lockdep.c:2800 [inline]
__lock_acquire+0x2469/0x5490 kernel/locking/lockdep.c:3793
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
__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:1752 [inline]
__io_submit_one fs/aio.c:1826 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1863
__do_compat_sys_io_submit fs/aio.c:1964 [inline]
__se_compat_sys_io_submit fs/aio.c:1934 [inline]
__ia32_compat_sys_io_submit+0x1bf/0x570 fs/aio.c:1934
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7ff5849
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f7fcf0cc EFLAGS: 00000296 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 00000000f7fd0000 RCX: 0000000000000001
RDX: 0000000020000600 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000