Hello,
syzbot found the following crash on:
HEAD commit: 17da61ae Add linux-next specific files for 20190814
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=127712e2600000
kernel config: https://syzkaller.appspot.com/x/.config?x=4733704ca85aaa66
dashboard link: https://syzkaller.appspot.com/bug?extid=af05535bb79520f95431
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+af05535bb79520f95431@xxxxxxxxxxxxxxxxxxxxxxxxx
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.3.0-rc4-next-20190814 #66 Not tainted
-----------------------------------------------------
syz-executor.1/25024 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff8880a374bbe8 (&fiq->waitq){+.+.}, at: spin_lock
include/linux/spinlock.h:338 [inline]
ffff8880a374bbe8 (&fiq->waitq){+.+.}, at: aio_poll fs/aio.c:1748 [inline]
ffff8880a374bbe8 (&fiq->waitq){+.+.}, at: __io_submit_one fs/aio.c:1822
[inline]
ffff8880a374bbe8 (&fiq->waitq){+.+.}, at: io_submit_one+0xefa/0x2ef0
fs/aio.c:1859
and this task is already holding:
ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq
include/linux/spinlock.h:363 [inline]
ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll
fs/aio.c:1746 [inline]
ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one
fs/aio.c:1822 [inline]
ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at:
io_submit_one+0xeb5/0x2ef0 fs/aio.c:1859
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:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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:618
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:2157 [inline]
rcu_core+0x581/0x1560 kernel/rcu/tree.c:2377
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386
__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:536 [inline]
smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
constant_test_bit arch/x86/include/asm/bitops.h:207 [inline]
test_bit include/asm-generic/bitops-instrumented.h:238 [inline]
test_ti_thread_flag include/linux/thread_info.h:84 [inline]
need_resched include/linux/sched.h:1827 [inline]
mutex_spin_on_owner+0x7b/0x330 kernel/locking/mutex.c:568
mutex_optimistic_spin kernel/locking/mutex.c:673 [inline]
__mutex_lock_common kernel/locking/mutex.c:959 [inline]
__mutex_lock+0x330/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
addrconf_dad_work+0xad/0x1150 net/ipv6/addrconf.c:4032
process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
worker_thread+0x98/0xe40 kernel/workqueue.c:2415
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
to a SOFTIRQ-irq-unsafe lock:
(&fiq->waitq){+.+.}
... which became SOFTIRQ-irq-unsafe at:
...
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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]
flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
fuse_request_queue_background+0x2f8/0x5a0 fs/fuse/dev.c:676
fuse_request_send_background+0x58/0x110 fs/fuse/dev.c:687
cuse_send_init fs/fuse/cuse.c:459 [inline]
cuse_channel_open+0x5ba/0x830 fs/fuse/cuse.c:519
misc_open+0x395/0x4c0 drivers/char/misc.c:141
chrdev_open+0x245/0x6b0 fs/char_dev.c:414
do_dentry_open+0x4df/0x1250 fs/open.c:797
vfs_open+0xa0/0xd0 fs/open.c:914
do_last fs/namei.c:3416 [inline]
path_openat+0x10e9/0x4630 fs/namei.c:3533
do_filp_open+0x1a1/0x280 fs/namei.c:3563
do_sys_open+0x3fe/0x5d0 fs/open.c:1097
__do_sys_openat fs/open.c:1124 [inline]
__se_sys_openat fs/open.c:1118 [inline]
__x64_sys_openat+0x9d/0x100 fs/open.c:1118
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
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);
<Interrupt>
lock(&(&ctx->ctx_lock)->rlock);
*** DEADLOCK ***
1 lock held by syz-executor.1/25024:
#0: ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq
include/linux/spinlock.h:363 [inline]
#0: ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll
fs/aio.c:1746 [inline]
#0: ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one
fs/aio.c:1822 [inline]
#0: ffff88806001fc58 (&(&ctx->ctx_lock)->rlock){..-.}, at:
io_submit_one+0xeb5/0x2ef0 fs/aio.c:1859
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:4487
__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:618
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:2157 [inline]
rcu_core+0x581/0x1560 kernel/rcu/tree.c:2377
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386
__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:536 [inline]
smp_apic_timer_interrupt+0x1a3/0x610
arch/x86/kernel/apic/apic.c:1095
apic_timer_interrupt+0xf/0x20
arch/x86/entry/entry_64.S:830
constant_test_bit arch/x86/include/asm/bitops.h:207
[inline]
test_bit include/asm-generic/bitops-instrumented.h:238
[inline]
test_ti_thread_flag include/linux/thread_info.h:84
[inline]
need_resched include/linux/sched.h:1827 [inline]
mutex_spin_on_owner+0x7b/0x330
kernel/locking/mutex.c:568
mutex_optimistic_spin kernel/locking/mutex.c:673
[inline]
__mutex_lock_common kernel/locking/mutex.c:959 [inline]
__mutex_lock+0x330/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
addrconf_dad_work+0xad/0x1150 net/ipv6/addrconf.c:4032
process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
worker_thread+0x98/0xe40 kernel/workqueue.c:2415
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
INITIAL USE at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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:618
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:2157 [inline]
rcu_core+0x581/0x1560 kernel/rcu/tree.c:2377
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386
__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:536 [inline]
smp_apic_timer_interrupt+0x1a3/0x610
arch/x86/kernel/apic/apic.c:1095
apic_timer_interrupt+0xf/0x20
arch/x86/entry/entry_64.S:830
constant_test_bit arch/x86/include/asm/bitops.h:207
[inline]
test_bit include/asm-generic/bitops-instrumented.h:238
[inline]
test_ti_thread_flag include/linux/thread_info.h:84
[inline]
need_resched include/linux/sched.h:1827 [inline]
mutex_spin_on_owner+0x7b/0x330 kernel/locking/mutex.c:568
mutex_optimistic_spin kernel/locking/mutex.c:673 [inline]
__mutex_lock_common kernel/locking/mutex.c:959 [inline]
__mutex_lock+0x330/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
addrconf_dad_work+0xad/0x1150 net/ipv6/addrconf.c:4032
process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
worker_thread+0x98/0xe40 kernel/workqueue.c:2415
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
}
... key at: [<ffffffff8ab00360>] __key.54228+0x0/0x40
... acquired at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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:1748 [inline]
__io_submit_one fs/aio.c:1822 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1859
__do_sys_io_submit fs/aio.c:1918 [inline]
__se_sys_io_submit fs/aio.c:1888 [inline]
__x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1888
do_syscall_64+0xfa/0x760 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:
-> (&fiq->waitq){+.+.} {
HARDIRQ-ON-W at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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]
flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
fuse_request_queue_background+0x2f8/0x5a0
fs/fuse/dev.c:676
fuse_request_send_background+0x58/0x110
fs/fuse/dev.c:687
cuse_send_init fs/fuse/cuse.c:459 [inline]
cuse_channel_open+0x5ba/0x830 fs/fuse/cuse.c:519
misc_open+0x395/0x4c0 drivers/char/misc.c:141
chrdev_open+0x245/0x6b0 fs/char_dev.c:414
do_dentry_open+0x4df/0x1250 fs/open.c:797
vfs_open+0xa0/0xd0 fs/open.c:914
do_last fs/namei.c:3416 [inline]
path_openat+0x10e9/0x4630 fs/namei.c:3533
do_filp_open+0x1a1/0x280 fs/namei.c:3563
do_sys_open+0x3fe/0x5d0 fs/open.c:1097
__do_sys_openat fs/open.c:1124 [inline]
__se_sys_openat fs/open.c:1118 [inline]
__x64_sys_openat+0x9d/0x100 fs/open.c:1118
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
SOFTIRQ-ON-W at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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]
flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
fuse_request_queue_background+0x2f8/0x5a0
fs/fuse/dev.c:676
fuse_request_send_background+0x58/0x110
fs/fuse/dev.c:687
cuse_send_init fs/fuse/cuse.c:459 [inline]
cuse_channel_open+0x5ba/0x830 fs/fuse/cuse.c:519
misc_open+0x395/0x4c0 drivers/char/misc.c:141
chrdev_open+0x245/0x6b0 fs/char_dev.c:414
do_dentry_open+0x4df/0x1250 fs/open.c:797
vfs_open+0xa0/0xd0 fs/open.c:914
do_last fs/namei.c:3416 [inline]
path_openat+0x10e9/0x4630 fs/namei.c:3533
do_filp_open+0x1a1/0x280 fs/namei.c:3563
do_sys_open+0x3fe/0x5d0 fs/open.c:1097
__do_sys_openat fs/open.c:1124 [inline]
__se_sys_openat fs/open.c:1118 [inline]
__x64_sys_openat+0x9d/0x100 fs/open.c:1118
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
INITIAL USE at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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]
flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
fuse_request_queue_background+0x2f8/0x5a0
fs/fuse/dev.c:676
fuse_request_send_background+0x58/0x110 fs/fuse/dev.c:687
cuse_send_init fs/fuse/cuse.c:459 [inline]
cuse_channel_open+0x5ba/0x830 fs/fuse/cuse.c:519
misc_open+0x395/0x4c0 drivers/char/misc.c:141
chrdev_open+0x245/0x6b0 fs/char_dev.c:414
do_dentry_open+0x4df/0x1250 fs/open.c:797
vfs_open+0xa0/0xd0 fs/open.c:914
do_last fs/namei.c:3416 [inline]
path_openat+0x10e9/0x4630 fs/namei.c:3533
do_filp_open+0x1a1/0x280 fs/namei.c:3563
do_sys_open+0x3fe/0x5d0 fs/open.c:1097
__do_sys_openat fs/open.c:1124 [inline]
__se_sys_openat fs/open.c:1118 [inline]
__x64_sys_openat+0x9d/0x100 fs/open.c:1118
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
}
... key at: [<ffffffff8ab9a180>] __key.45697+0x0/0x40
... acquired at:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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:1748 [inline]
__io_submit_one fs/aio.c:1822 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1859
__do_sys_io_submit fs/aio.c:1918 [inline]
__se_sys_io_submit fs/aio.c:1888 [inline]
__x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1888
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
stack backtrace:
CPU: 0 PID: 25024 Comm: syz-executor.1 Not tainted 5.3.0-rc4-next-20190814
#66
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:2095 [inline]
check_irq_usage.cold+0x586/0x6fe kernel/locking/lockdep.c:2293
check_prev_add kernel/locking/lockdep.c:2480 [inline]
check_prevs_add kernel/locking/lockdep.c:2581 [inline]
validate_chain kernel/locking/lockdep.c:2971 [inline]
__lock_acquire+0x25d0/0x4e70 kernel/locking/lockdep.c:3955
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
__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:1748 [inline]
__io_submit_one fs/aio.c:1822 [inline]
io_submit_one+0xefa/0x2ef0 fs/aio.c:1859
__do_sys_io_submit fs/aio.c:1918 [inline]
__se_sys_io_submit fs/aio.c:1888 [inline]
__x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1888
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
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:00007f9e07853c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829
RDX: 0000000020000440 RSI: 0000000000000001 RDI: 00007f9e07833000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9e078546d4
R13: 00000000004c0c19 R14: 00000000004d3c40 R15: 00000000ffffffff
---
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