[syzbot] WARNING: locking bug in complete_all (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bbed346d5a96 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=13b7a1b8880000
kernel config: https://syzkaller.appspot.com/x/.config?x=aae2d21e7dd80684
dashboard link: https://syzkaller.appspot.com/bug?extid=89f4560b096bdbf2cd4b
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/11078f50b80b/disk-bbed346d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/398e5f1e6c84/vmlinux-bbed346d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89f456...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 1 PID: 976 at kernel/locking/lockdep.c:231 check_wait_context kernel/locking/lockdep.c:4727 [inline]
WARNING: CPU: 1 PID: 976 at kernel/locking/lockdep.c:231 __lock_acquire+0x2b0/0x30a4 kernel/locking/lockdep.c:5003
Modules linked in:
CPU: 1 PID: 976 Comm: kworker/u4:3 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Workqueue: bat_events batadv_nc_worker
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : check_wait_context kernel/locking/lockdep.c:4727 [inline]
pc : __lock_acquire+0x2b0/0x30a4 kernel/locking/lockdep.c:5003
lr : hlock_class kernel/locking/lockdep.c:231 [inline]
lr : check_wait_context kernel/locking/lockdep.c:4727 [inline]
lr : __lock_acquire+0x298/0x30a4 kernel/locking/lockdep.c:5003
sp : ffff80000800ba20
x29: ffff80000800bb00 x28: 0000000000000004 x27: ffff0000c6431b20
x26: ffff0000fc9faa30 x25: ffff0000c6432550 x24: 0000000000000080
x23: 0000000000000000 x22: 0000000000000001 x21: 0000000000000000
x20: 0000000000000000 x19: aaab27e894723d1c x18: 000000000000ba7e
x17: ffff8001f1d7d000 x16: ffff80000db49158 x15: ffff0000c6431a80
x14: 0000000000000000 x13: 0000000000000012 x12: ffff80000d5ef920
x11: ff808000081c0d5c x10: ffff80000dd0b198 x9 : 68ac72b3ffb08100
x8 : 0000000000000000 x7 : 4e5241575f534b43 x6 : ffff80000819545c
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000100010003 x0 : 0000000000000016
Call trace:
check_wait_context kernel/locking/lockdep.c:4727 [inline]
__lock_acquire+0x2b0/0x30a4 kernel/locking/lockdep.c:5003
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x6c/0xb4 kernel/locking/spinlock.c:162
complete_all+0x24/0xa0 kernel/sched/completion.c:63
drm_send_event_helper+0x50/0x228 drivers/gpu/drm/drm_file.c:783
drm_send_event_timestamp_locked+0x34/0x48 drivers/gpu/drm/drm_file.c:827
send_vblank_event drivers/gpu/drm/drm_vblank.c:1016 [inline]
drm_handle_vblank_events+0x258/0x334 drivers/gpu/drm/drm_vblank.c:1914
drm_handle_vblank+0x188/0x310 drivers/gpu/drm/drm_vblank.c:1975
drm_crtc_handle_vblank+0x24/0x38 drivers/gpu/drm/drm_vblank.c:2009
vkms_vblank_simulate+0x84/0x1b4 drivers/gpu/drm/vkms/vkms_crtc.c:29
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x210/0x390 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x12c/0x510 kernel/time/hrtimer.c:1811
timer_handler drivers/clocksource/arm_arch_timer.c:653 [inline]
arch_timer_handler_virt+0x58/0x6c drivers/clocksource/arm_arch_timer.c:664
handle_percpu_devid_irq+0xb0/0x1c8 kernel/irq/chip.c:930
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq_desc kernel/irq/irqdesc.c:648 [inline]
generic_handle_domain_irq+0x4c/0x6c kernel/irq/irqdesc.c:704
gic_handle_irq+0x78/0x1b4 drivers/irqchip/irq-gic.c:359
call_on_irq_stack+0x2c/0x54 arch/arm64/kernel/entry.S:889
do_interrupt_handler+0x7c/0xc0 arch/arm64/kernel/entry-common.c:274
__el1_irq arch/arm64/kernel/entry-common.c:470 [inline]
el1_interrupt+0x34/0x68 arch/arm64/kernel/entry-common.c:485
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:490
el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:577
arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline]
__local_bh_enable_ip+0x144/0x1a4 kernel/softirq.c:401
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x48/0x58 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:394 [inline]
batadv_nc_purge_paths+0x1d0/0x214 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x394/0x484 net/batman-adv/network-coding.c:720
process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
worker_thread+0x340/0x610 kernel/workqueue.c:2436
kthread+0x12c/0x158 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
irq event stamp: 2991678
hardirqs last enabled at (2991677): [<ffff800008102154>] __local_bh_enable_ip+0x13c/0x1a4 kernel/softirq.c:401
hardirqs last disabled at (2991678): [<ffff80000bfb6088>] __el1_irq arch/arm64/kernel/entry-common.c:467 [inline]
hardirqs last disabled at (2991678): [<ffff80000bfb6088>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:485
softirqs last enabled at (2991676): [<ffff80000becc320>] spin_unlock_bh include/linux/spinlock.h:394 [inline]
softirqs last enabled at (2991676): [<ffff80000becc320>] batadv_nc_purge_paths+0x1d0/0x214 net/batman-adv/network-coding.c:471
softirqs last disabled at (2991674): [<ffff80000becc1b0>] spin_lock_bh include/linux/spinlock.h:354 [inline]
softirqs last disabled at (2991674): [<ffff80000becc1b0>] batadv_nc_purge_paths+0x60/0x214 net/batman-adv/network-coding.c:442
---[ end trace 0000000000000000 ]---
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8
Mem abort info:
ESR = 0x0000000096000007
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x07: level 3 translation fault
Data abort info:
ISV = 0, ISS = 0x00000007
CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=000000010affc000
[00000000000000b8] pgd=080000010a948003, p4d=080000010a948003, pud=080000010ad99003, pmd=080000010ada3003, pte=0000000000000000
Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 976 Comm: kworker/u4:3 Tainted: G W 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Workqueue: bat_events batadv_nc_worker
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : check_wait_context kernel/locking/lockdep.c:4727 [inline]
pc : __lock_acquire+0x2d0/0x30a4 kernel/locking/lockdep.c:5003
lr : hlock_class kernel/locking/lockdep.c:231 [inline]
lr : check_wait_context kernel/locking/lockdep.c:4727 [inline]
lr : __lock_acquire+0x298/0x30a4 kernel/locking/lockdep.c:5003
sp : ffff80000800ba20
x29: ffff80000800bb00 x28: 0000000000000004 x27: ffff0000c6431b20
x26: ffff0000fc9faa30 x25: ffff0000c6432550 x24: 0000000000000080
x23: 0000000000000000 x22: 0000000000000001 x21: 0000000000000000
x20: 0000000000000000 x19: aaab27e894723d1c x18: 000000000000ba7e
x17: ffff8001f1d7d000 x16: ffff80000db49158 x15: ffff0000c6431a80
x14: 0000000000000000 x13: 0000000000000012 x12: ffff80000d5ef920
x11: ff808000081c0d5c x10: ffff80000dd0b198 x9 : 00000000000c5d1c
x8 : 0000000000000000 x7 : 4e5241575f534b43 x6 : ffff80000819545c
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000100010003 x0 : 0000000000000016
Call trace:
hlock_class kernel/locking/lockdep.c:222 [inline]
check_wait_context kernel/locking/lockdep.c:4728 [inline]
__lock_acquire+0x2d0/0x30a4 kernel/locking/lockdep.c:5003
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x6c/0xb4 kernel/locking/spinlock.c:162
complete_all+0x24/0xa0 kernel/sched/completion.c:63
drm_send_event_helper+0x50/0x228 drivers/gpu/drm/drm_file.c:783
drm_send_event_timestamp_locked+0x34/0x48 drivers/gpu/drm/drm_file.c:827
send_vblank_event drivers/gpu/drm/drm_vblank.c:1016 [inline]
drm_handle_vblank_events+0x258/0x334 drivers/gpu/drm/drm_vblank.c:1914
drm_handle_vblank+0x188/0x310 drivers/gpu/drm/drm_vblank.c:1975
drm_crtc_handle_vblank+0x24/0x38 drivers/gpu/drm/drm_vblank.c:2009
vkms_vblank_simulate+0x84/0x1b4 drivers/gpu/drm/vkms/vkms_crtc.c:29
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x210/0x390 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x12c/0x510 kernel/time/hrtimer.c:1811
timer_handler drivers/clocksource/arm_arch_timer.c:653 [inline]
arch_timer_handler_virt+0x58/0x6c drivers/clocksource/arm_arch_timer.c:664
handle_percpu_devid_irq+0xb0/0x1c8 kernel/irq/chip.c:930
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq_desc kernel/irq/irqdesc.c:648 [inline]
generic_handle_domain_irq+0x4c/0x6c kernel/irq/irqdesc.c:704
gic_handle_irq+0x78/0x1b4 drivers/irqchip/irq-gic.c:359
call_on_irq_stack+0x2c/0x54 arch/arm64/kernel/entry.S:889
do_interrupt_handler+0x7c/0xc0 arch/arm64/kernel/entry-common.c:274
__el1_irq arch/arm64/kernel/entry-common.c:470 [inline]
el1_interrupt+0x34/0x68 arch/arm64/kernel/entry-common.c:485
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:490
el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:577
arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline]
__local_bh_enable_ip+0x144/0x1a4 kernel/softirq.c:401
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x48/0x58 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:394 [inline]
batadv_nc_purge_paths+0x1d0/0x214 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x394/0x484 net/batman-adv/network-coding.c:720
process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
worker_thread+0x340/0x610 kernel/workqueue.c:2436
kthread+0x12c/0x158 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
Code: b002db8a 91056210 9106614a b9400329 (3942e114)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: b002db8a adrp x10, 0x5b71000
4: 91056210 add x16, x16, #0x158
8: 9106614a add x10, x10, #0x198
c: b9400329 ldr w9, [x25]
* 10: 3942e114 ldrb w20, [x8, #184] <-- trapping instruction


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.