[v6.1] possible deadlock in throtl_pending_timer_fn

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8a923980a190 Linux 6.1.16
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=131ba40cc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=890c08c5270b796
dashboard link: https://syzkaller.appspot.com/bug?extid=bd917fbd065e28eccc86
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b5419f7c9b17/disk-8a923980.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eda486f8541a/vmlinux-8a923980.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e1451605e837/bzImage-8a923980.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd917f...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.1.16-syzkaller #0 Not tainted
------------------------------------------------------
udevd/3821 is trying to acquire lock:
ffff888147498920 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline]
ffff888147498920 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193

but task is already holding lock:
ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x840 kernel/time/timer.c:1464

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 ((&sq->pending_timer)){+.-.}-{0:0}:
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
del_timer_sync+0x111/0x2e0 kernel/time/timer.c:1417
throtl_pd_free+0x15/0x40 block/blk-throttle.c:493
blkcg_deactivate_policy+0x32d/0x550 block/blk-cgroup.c:1499
blk_throtl_exit+0xa6/0x140 block/blk-throttle.c:2406
disk_release+0x1dd/0x380 block/genhd.c:1171
device_release+0x91/0x1c0
kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x224/0x460 lib/kobject.c:729
do_floppy_init+0x373/0xc59 drivers/block/floppy.c:4758
async_run_entry_fn+0xa2/0x410 kernel/async.c:127
process_one_work+0x909/0x1380 kernel/workqueue.c:2289
worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436
kthread+0x268/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

-> #1 (&blkcg->lock){....}-{2:2}:
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
blkg_create+0xa94/0x1280 block/blk-cgroup.c:336
blkcg_init_disk+0xee/0x350 block/blk-cgroup.c:1260
__alloc_disk_node+0x2ce/0x590 block/genhd.c:1385
__blk_alloc_disk+0x2c/0x80 block/genhd.c:1424
brd_alloc+0x2f9/0x6a0 drivers/block/brd.c:397
brd_init+0x100/0x1c2 drivers/block/brd.c:484
do_one_initcall+0x2d6/0xa80 init/main.c:1303
do_initcall_level+0x157/0x207 init/main.c:1376
do_initcalls+0x49/0x86 init/main.c:1392
kernel_init_freeable+0x473/0x61f init/main.c:1631
kernel_init+0x19/0x290 init/main.c:1519
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

-> #0 (&q->queue_lock){..-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:375 [inline]
throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193
call_timer_fn+0x200/0x840 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x30d/0xb1b kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1107
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
tomoyo_check_path_acl+0x7b/0x1c0 security/tomoyo/file.c:258
tomoyo_check_acl+0x126/0x3e0 security/tomoyo/domain.c:175
tomoyo_path_permission+0x1af/0x360 security/tomoyo/file.c:586
tomoyo_path_perm+0x436/0x6b0 security/tomoyo/file.c:838
tomoyo_path_unlink+0xcc/0x100 security/tomoyo/tomoyo.c:149
security_path_unlink+0xd7/0x130 security/security.c:1175
do_unlinkat+0x3d7/0x940 fs/namei.c:4316
__do_sys_unlink fs/namei.c:4368 [inline]
__se_sys_unlink fs/namei.c:4366 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4366
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
&q->queue_lock --> &blkcg->lock --> (&sq->pending_timer)

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock((&sq->pending_timer));
lock(&blkcg->lock);
lock((&sq->pending_timer));
lock(&q->queue_lock);

*** DEADLOCK ***

4 locks held by udevd/3821:
#0: ffff88807dd46460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
#1: ffff88807dba3b60 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:791 [inline]
#1: ffff88807dba3b60 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: do_unlinkat+0x260/0x940 fs/namei.c:4303
#2: ffffffff8d50cc88 (tomoyo_ss){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305
#3: ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#3: ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x840 kernel/time/timer.c:1464

stack backtrace:
CPU: 0 PID: 3821 Comm: udevd Not tainted 6.1.16-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:375 [inline]
throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193
call_timer_fn+0x200/0x840 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x30d/0xb1b kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1107
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:tomoyo_check_path_acl+0x7b/0x1c0 security/tomoyo/file.c:258
Code: 01 00 00 0f b6 6d 00 bf 20 00 00 00 89 ee e8 ec 5d 95 fd 83 fd 1f 0f 87 2c 01 00 00 e8 7e 5b 95 fd bb 01 00 00 00 89 e9 d3 e3 <89> de 44 21 fe 31 ff e8 c9 5e 95 fd 44 21 fb 74 56 49 8d 6d 18 48
RSP: 0018:ffffc90004a979c0 EFLAGS: 00000202
RAX: ffffffff83f505a2 RBX: 0000000000000010 RCX: 0000000000000004
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000020
RBP: 0000000000000004 R08: ffffffff83f50594 R09: ffffffff83f51bf4
R10: 0000000000000003 R11: ffff88801f618000 R12: dffffc0000000000
R13: ffffc90004a97ae0 R14: ffff888027164e80 R15: 0000000000000022
tomoyo_check_acl+0x126/0x3e0 security/tomoyo/domain.c:175
tomoyo_path_permission+0x1af/0x360 security/tomoyo/file.c:586
tomoyo_path_perm+0x436/0x6b0 security/tomoyo/file.c:838
tomoyo_path_unlink+0xcc/0x100 security/tomoyo/tomoyo.c:149
security_path_unlink+0xd7/0x130 security/security.c:1175
do_unlinkat+0x3d7/0x940 fs/namei.c:4316
__do_sys_unlink fs/namei.c:4368 [inline]
__se_sys_unlink fs/namei.c:4366 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4366
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f681479a2d7
Code: f0 ff ff 73 01 c3 48 8b 0d 9e db 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 71 db 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe1899b688 EFLAGS: 00000202 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000557e06eba120 RCX: 00007f681479a2d7
RDX: 0000000000000000 RSI: 0000557e088ee9e4 RDI: 00007ffe1899b698
RBP: 00007ffe1899b698 R08: 0000000000000000 R09: 0000557e0890ce10
R10: 0000000001ec3f43 R11: 0000000000000202 R12: 0000557e088f9fb0
R13: 000000000aba9500 R14: 0000000003938700 R15: 0000557e06eba160
</TASK>
----------------
Code disassembly (best guess):
0: 01 00 add %eax,(%rax)
2: 00 0f add %cl,(%rdi)
4: b6 6d mov $0x6d,%dh
6: 00 bf 20 00 00 00 add %bh,0x20(%rdi)
c: 89 ee mov %ebp,%esi
e: e8 ec 5d 95 fd callq 0xfd955dff
13: 83 fd 1f cmp $0x1f,%ebp
16: 0f 87 2c 01 00 00 ja 0x148
1c: e8 7e 5b 95 fd callq 0xfd955b9f
21: bb 01 00 00 00 mov $0x1,%ebx
26: 89 e9 mov %ebp,%ecx
28: d3 e3 shl %cl,%ebx
* 2a: 89 de mov %ebx,%esi <-- trapping instruction
2c: 44 21 fe and %r15d,%esi
2f: 31 ff xor %edi,%edi
31: e8 c9 5e 95 fd callq 0xfd955eff
36: 44 21 fb and %r15d,%ebx
39: 74 56 je 0x91
3b: 49 8d 6d 18 lea 0x18(%r13),%rbp
3f: 48 rex.W


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 8a923980a190 Linux 6.1.16
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=17a42b5cc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=fc32d7322291d081

dashboard link: https://syzkaller.appspot.com/bug?extid=bd917fbd065e28eccc86
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14bdddccc80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1539b888c80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bf09a4a426d0/disk-8a923980.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/99e88c1c3e26/vmlinux-8a923980.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d13a720e0836/Image-8a923980.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd917f...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.1.16-syzkaller #0 Not tainted
------------------------------------------------------

syz-executor155/4313 is trying to acquire lock:
ffff0000cfd20cc8 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline]
ffff0000cfd20cc8 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0x104/0xdcc block/blk-throttle.c:1193

but task is already holding lock:

ffff800008017c80 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
ffff800008017c80 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd0/0xcf4 kernel/time/timer.c:1464

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 ((&sq->pending_timer)){+.-.}-{0:0}:

del_timer_sync+0x9c/0x210 kernel/time/timer.c:1417
throtl_pd_free+0x20/0x48 block/blk-throttle.c:493
blkcg_deactivate_policy+0x2d8/0x4bc block/blk-cgroup.c:1499
blk_throtl_exit+0x9c/0x13c block/blk-throttle.c:2406
blkcg_exit_disk+0x4c/0x5c block/blk-cgroup.c:1301
disk_release+0x170/0x2d8 block/genhd.c:1171
device_release+0x8c/0x1ac

kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]

kobject_put+0x2a8/0x41c lib/kobject.c:729
put_device+0x28/0x40 drivers/base/core.c:3772
put_disk+0x4c/0x64 block/genhd.c:1450
nbd_dev_remove drivers/block/nbd.c:253 [inline]
nbd_dev_remove_work+0x50/0xe8 drivers/block/nbd.c:269
process_one_work+0x868/0x16f4 kernel/workqueue.c:2289
worker_thread+0x8e4/0xfec kernel/workqueue.c:2436
kthread+0x24c/0x2d4 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

-> #1 (&blkcg->lock){....}-{2:2}:

__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x54/0x6c kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
blkg_create+0x9f4/0x1158 block/blk-cgroup.c:336
blkcg_init_disk+0xe4/0x32c block/blk-cgroup.c:1260
__alloc_disk_node+0x26c/0x484 block/genhd.c:1385
__blk_alloc_disk+0x40/0xbc block/genhd.c:1424
brd_alloc+0x2ac/0x5c8 drivers/block/brd.c:397
brd_init+0x108/0x1c4 drivers/block/brd.c:484
do_one_initcall+0x310/0xda4 init/main.c:1303
do_initcall_level+0x154/0x214 init/main.c:1376
do_initcalls+0x58/0xac init/main.c:1392
do_basic_setup+0x8c/0xa0 init/main.c:1411
kernel_init_freeable+0x3a4/0x528 init/main.c:1631
kernel_init+0x24/0x29c init/main.c:1519
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

-> #0 (&q->queue_lock){..-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]

validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
lock_acquire+0x300/0x8e4 kernel/locking/lockdep.c:5669
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x70/0x9c kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:375 [inline]
throtl_pending_timer_fn+0x104/0xdcc block/blk-throttle.c:1193
call_timer_fn+0x270/0xcf4 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x554/0x718 kernel/time/timer.c:1790
run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1803
__do_softirq+0x37c/0xff4 kernel/softirq.c:571
____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
call_on_irq_stack+0x2c/0x54 arch/arm64/kernel/entry.S:889
do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x28c/0x534 kernel/softirq.c:650
irq_exit_rcu+0x14/0x84 kernel/softirq.c:662
__el1_irq arch/arm64/kernel/entry-common.c:472 [inline]
el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:577
arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
__free_object+0x1c0/0x868 lib/debugobjects.c:358
free_object lib/debugobjects.c:427 [inline]
debug_object_free+0x27c/0x438 lib/debugobjects.c:857
destroy_hrtimer_on_stack kernel/time/hrtimer.c:452 [inline]
hrtimer_nanosleep+0x2d4/0x384 kernel/time/hrtimer.c:2112
common_nsleep+0xa8/0xc0 kernel/time/posix-timers.c:1236
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1277 [inline]
__se_sys_clock_nanosleep kernel/time/posix-timers.c:1254 [inline]
__arm64_sys_clock_nanosleep+0x350/0x38c kernel/time/posix-timers.c:1254
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

other info that might help us debug this:

Chain exists of:
&q->queue_lock --> &blkcg->lock --> (&sq->pending_timer)

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock((&sq->pending_timer));
lock(&blkcg->lock);
lock((&sq->pending_timer));
lock(&q->queue_lock);

*** DEADLOCK ***

1 lock held by syz-executor155/4313:
#0: ffff800008017c80 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#0: ffff800008017c80 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd0/0xcf4 kernel/time/timer.c:1464

stack backtrace:
CPU: 1 PID: 4313 Comm: syz-executor155 Not tainted 6.1.16-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x5c lib/dump_stack.c:113
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056
check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2178

check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]

validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
lock_acquire+0x300/0x8e4 kernel/locking/lockdep.c:5669
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x70/0x9c kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:375 [inline]
throtl_pending_timer_fn+0x104/0xdcc block/blk-throttle.c:1193
call_timer_fn+0x270/0xcf4 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x554/0x718 kernel/time/timer.c:1790
run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1803
__do_softirq+0x37c/0xff4 kernel/softirq.c:571
____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
call_on_irq_stack+0x2c/0x54 arch/arm64/kernel/entry.S:889
do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x28c/0x534 kernel/softirq.c:650
irq_exit_rcu+0x14/0x84 kernel/softirq.c:662
__el1_irq arch/arm64/kernel/entry-common.c:472 [inline]
el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:577
arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
__free_object+0x1c0/0x868 lib/debugobjects.c:358
free_object lib/debugobjects.c:427 [inline]
debug_object_free+0x27c/0x438 lib/debugobjects.c:857
destroy_hrtimer_on_stack kernel/time/hrtimer.c:452 [inline]
hrtimer_nanosleep+0x2d4/0x384 kernel/time/hrtimer.c:2112
common_nsleep+0xa8/0xc0 kernel/time/posix-timers.c:1236
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1277 [inline]
__se_sys_clock_nanosleep kernel/time/posix-timers.c:1254 [inline]
__arm64_sys_clock_nanosleep+0x350/0x38c kernel/time/posix-timers.c:1254
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

[syzbot]

syzbot suspects this issue was fixed by commit:

commit b5dae1cd0d8368b4338430ff93403df67f0b8bcc
Author: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Date: Sat Mar 11 09:34:32 2023 +0000

Revert "blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()"

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16e4fb53c80000
start commit: 8a923980a190 Linux 6.1.16
git tree: linux-6.1.y

kernel config: https://syzkaller.appspot.com/x/.config?x=fc32d7322291d081
dashboard link: https://syzkaller.appspot.com/bug?extid=bd917fbd065e28eccc86

userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=128f047cc80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15255f38c80000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: Revert "blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()"

For information about bisection process see: https://goo.gl/tpsmEJ#bisection