=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.0.0-rc2-next-20190118 #15 Not tainted
-----------------------------------------------------
syz-executor5/21036 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
000000003a631259 (&ctx->fault_pending_wqh){+.+.}, at: spin_lock include/linux/spinlock.h:329 [inline]
000000003a631259 (&ctx->fault_pending_wqh){+.+.}, at: userfaultfd_ctx_read+0x690/0x2060 fs/userfaultfd.c:1040
and this task is already holding:
000000004940f7d8 (&ctx->fd_wqh){....}, at: spin_lock_irq include/linux/spinlock.h:354 [inline]
000000004940f7d8 (&ctx->fd_wqh){....}, at: userfaultfd_ctx_read+0x25e/0x2060 fs/userfaultfd.c:1036
which would create a new lock dependency:
(&ctx->fd_wqh){....} -> (&ctx->fault_pending_wqh){+.+.}
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:3860
__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:2486 [inline]
invoke_rcu_callbacks kernel/rcu/tree.c:2799 [inline]
rcu_core+0xc4a/0x1680 kernel/rcu/tree.c:2780
__do_softirq+0x30b/0xb11 kernel/softirq.c:292
run_ksoftirqd kernel/softirq.c:654 [inline]
run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646
smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164
kthread+0x357/0x430 kernel/kthread.c:247
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
to a SOFTIRQ-irq-unsafe lock:
(&ctx->fault_pending_wqh){+.+.}
... which became SOFTIRQ-irq-unsafe at:
...
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
__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]
handle_userfault+0x901/0x2510 fs/userfaultfd.c:461
do_anonymous_page mm/memory.c:2939 [inline]
handle_pte_fault mm/memory.c:3803 [inline]
__handle_mm_fault+0x45c5/0x5610 mm/memory.c:3929
handle_mm_fault+0x4ec/0xc80 mm/memory.c:3966
do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
__do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1541
do_page_fault+0xe6/0x7d8 arch/x86/mm/fault.c:1572
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
__get_user_4+0x21/0x30 arch/x86/lib/getuser.S:76
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3017
__sys_setsockopt+0x1b0/0x3a0 net/socket.c:1902
__do_sys_setsockopt net/socket.c:1913 [inline]
__se_sys_setsockopt net/socket.c:1910 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
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:
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-executor5/21036:
#0: 000000004940f7d8 (&ctx->fd_wqh){....}, at: spin_lock_irq include/linux/spinlock.h:354 [inline]
#0: 000000004940f7d8 (&ctx->fd_wqh){....}, at: userfaultfd_ctx_read+0x25e/0x2060 fs/userfaultfd.c:1036
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:3860
__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:2486 [inline]
invoke_rcu_callbacks kernel/rcu/tree.c:2799 [inline]
rcu_core+0xc4a/0x1680 kernel/rcu/tree.c:2780
__do_softirq+0x30b/0xb11 kernel/softirq.c:292
run_ksoftirqd kernel/softirq.c:654 [inline]
run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646
smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164
kthread+0x357/0x430 kernel/kthread.c:247
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
INITIAL USE at:
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
__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]
aio_poll+0x790/0x14e0 fs/aio.c:1771
__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
}
... key at: [<ffffffff8b5940e0>] __key.52201+0x0/0x40
... acquired at:
__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
-> (&ctx->fd_wqh){....} {
INITIAL USE at:
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
__wake_up_common_lock+0x19b/0x390 kernel/sched/wait.c:120
__wake_up+0xe/0x10 kernel/sched/wait.c:145
handle_userfault+0xdfb/0x2510 fs/userfaultfd.c:487
do_anonymous_page mm/memory.c:2939 [inline]
handle_pte_fault mm/memory.c:3803 [inline]
__handle_mm_fault+0x45c5/0x5610 mm/memory.c:3929
handle_mm_fault+0x4ec/0xc80 mm/memory.c:3966
do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
__do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1541
do_page_fault+0xe6/0x7d8 arch/x86/mm/fault.c:1572
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
__get_user_4+0x21/0x30 arch/x86/lib/getuser.S:76
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3017
__sys_setsockopt+0x1b0/0x3a0 net/socket.c:1902
__do_sys_setsockopt net/socket.c:1913 [inline]
__se_sys_setsockopt net/socket.c:1910 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8b593e60>] __key.45089+0x0/0x40
... acquired at:
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
__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]
userfaultfd_ctx_read+0x690/0x2060 fs/userfaultfd.c:1040
userfaultfd_read+0x1e0/0x2c0 fs/userfaultfd.c:1198
__vfs_read+0x116/0xb20 fs/read_write.c:416
vfs_read+0x194/0x3e0 fs/read_write.c:452
ksys_read+0x105/0x260 fs/read_write.c:578
__do_sys_read fs/read_write.c:588 [inline]
__se_sys_read fs/read_write.c:586 [inline]
__x64_sys_read+0x73/0xb0 fs/read_write.c:586
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:
-> (&ctx->fault_pending_wqh){+.+.} {
HARDIRQ-ON-W at:
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
__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]
handle_userfault+0x901/0x2510 fs/userfaultfd.c:461
do_anonymous_page mm/memory.c:2939 [inline]
handle_pte_fault mm/memory.c:3803 [inline]
__handle_mm_fault+0x45c5/0x5610 mm/memory.c:3929
handle_mm_fault+0x4ec/0xc80 mm/memory.c:3966
do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
__do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1541
do_page_fault+0xe6/0x7d8 arch/x86/mm/fault.c:1572
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
__get_user_4+0x21/0x30 arch/x86/lib/getuser.S:76
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3017
__sys_setsockopt+0x1b0/0x3a0 net/socket.c:1902
__do_sys_setsockopt net/socket.c:1913 [inline]
__se_sys_setsockopt net/socket.c:1910 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
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:3860
__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]
handle_userfault+0x901/0x2510 fs/userfaultfd.c:461
do_anonymous_page mm/memory.c:2939 [inline]
handle_pte_fault mm/memory.c:3803 [inline]
__handle_mm_fault+0x45c5/0x5610 mm/memory.c:3929
handle_mm_fault+0x4ec/0xc80 mm/memory.c:3966
do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
__do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1541
do_page_fault+0xe6/0x7d8 arch/x86/mm/fault.c:1572
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
__get_user_4+0x21/0x30 arch/x86/lib/getuser.S:76
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3017
__sys_setsockopt+0x1b0/0x3a0 net/socket.c:1902
__do_sys_setsockopt net/socket.c:1913 [inline]
__se_sys_setsockopt net/socket.c:1910 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
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:3860
__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]
handle_userfault+0x901/0x2510 fs/userfaultfd.c:461
do_anonymous_page mm/memory.c:2939 [inline]
handle_pte_fault mm/memory.c:3803 [inline]
__handle_mm_fault+0x45c5/0x5610 mm/memory.c:3929
handle_mm_fault+0x4ec/0xc80 mm/memory.c:3966
do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
__do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1541
do_page_fault+0xe6/0x7d8 arch/x86/mm/fault.c:1572
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
__get_user_4+0x21/0x30 arch/x86/lib/getuser.S:76
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3017
__sys_setsockopt+0x1b0/0x3a0 net/socket.c:1902
__do_sys_setsockopt net/socket.c:1913 [inline]
__se_sys_setsockopt net/socket.c:1910 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8b593f20>] __key.45086+0x0/0x40
... acquired at:
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
__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]
userfaultfd_ctx_read+0x690/0x2060 fs/userfaultfd.c:1040
userfaultfd_read+0x1e0/0x2c0 fs/userfaultfd.c:1198
__vfs_read+0x116/0xb20 fs/read_write.c:416
vfs_read+0x194/0x3e0 fs/read_write.c:452
ksys_read+0x105/0x260 fs/read_write.c:578
__do_sys_read fs/read_write.c:588 [inline]
__se_sys_read fs/read_write.c:586 [inline]
__x64_sys_read+0x73/0xb0 fs/read_write.c:586
do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
stack backtrace:
CPU: 0 PID: 21036 Comm: syz-executor5 Not tainted 5.0.0-rc2-next-20190118 #15
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:1574 [inline]
check_usage.cold+0x5e2/0x917 kernel/locking/lockdep.c:1606
check_irq_usage kernel/locking/lockdep.c:1662 [inline]
check_prev_add_irq kernel/locking/lockdep_states.h:8 [inline]
check_prev_add kernel/locking/lockdep.c:1872 [inline]
check_prevs_add kernel/locking/lockdep.c:1980 [inline]
validate_chain kernel/locking/lockdep.c:2351 [inline]
__lock_acquire+0x2142/0x4a10 kernel/locking/lockdep.c:3339
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
__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]
userfaultfd_ctx_read+0x690/0x2060 fs/userfaultfd.c:1040
userfaultfd_read+0x1e0/0x2c0 fs/userfaultfd.c:1198
__vfs_read+0x116/0xb20 fs/read_write.c:416
vfs_read+0x194/0x3e0 fs/read_write.c:452
ksys_read+0x105/0x260 fs/read_write.c:578
__do_sys_read fs/read_write.c:588 [inline]
__se_sys_read fs/read_write.c:586 [inline]
__x64_sys_read+0x73/0xb0 fs/read_write.c:586
do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
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:00007f4b11e61c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099
RDX: 0000000000000064 RSI: 0000000020000400 RDI: 0000000000000003
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4b11e626d4
R13: 00000000004c3b5d R14: 00000000004d83b0 R15: 00000000ffffffff