[syzbot] [sound?] possible deadlock in _snd_pcm_stream_lock_irqsave (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1169a081180000
kernel config: https://syzkaller.appspot.com/x/.config?x=aef2a55903e5791c
dashboard link: https://syzkaller.appspot.com/bug?extid=18840ef96e57b83b7fea
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=113e5fae180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11271311180000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-fe46a7dd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/13635dbe3b05/vmlinux-fe46a7dd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bf54eeb6380c/bzImage-fe46a7dd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+18840e...@syzkaller.appspotmail.com

========================================================
WARNING: possible irq lock inversion dependency detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
--------------------------------------------------------
swapper/2/0 just changed the state of lock:
ffff88802a304110 (&group->lock#2){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170
but this lock took another, SOFTIRQ-unsafe lock in the past:
(&timer->lock){+.+.}-{2:2}


and interrupts could create inverse lock ordering between them.


other info that might help us debug this:
Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&timer->lock);
local_irq_disable();
lock(&group->lock#2);
lock(&timer->lock);
<Interrupt>
lock(&group->lock#2);

*** DEADLOCK ***

no locks held by swapper/2/0.

the shortest dependencies between 2nd lock and 1st lock:
-> (&timer->lock){+.+.}-{2:2} {
HARDIRQ-ON-W at:
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
class_spinlock_constructor include/linux/spinlock.h:561 [inline]
snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412
snd_timer_close+0x8b/0xf0 sound/core/timer.c:464
snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302
queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126
snd_seq_queue_delete+0x45/0x60 sound/core/seq/seq_queue.c:188
snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2526
delete_seq_queue.isra.0+0xc8/0x150 sound/core/seq/oss/seq_oss_init.c:371
odev_release+0x52/0x80 sound/core/seq/oss/seq_oss.c:144
__fput+0x270/0xb80 fs/file_table.c:422
task_work_run+0x14e/0x250 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa7d/0x2be0 kernel/exit.c:878
do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
__do_sys_exit_group kernel/exit.c:1038 [inline]
__se_sys_exit_group kernel/exit.c:1036 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
SOFTIRQ-ON-W at:
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
class_spinlock_constructor include/linux/spinlock.h:561 [inline]
snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412
snd_timer_close+0x8b/0xf0 sound/core/timer.c:464
snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302
queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126
snd_seq_queue_delete+0x45/0x60 sound/core/seq/seq_queue.c:188
snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2526
delete_seq_queue.isra.0+0xc8/0x150 sound/core/seq/oss/seq_oss_init.c:371
odev_release+0x52/0x80 sound/core/seq/oss/seq_oss.c:144
__fput+0x270/0xb80 fs/file_table.c:422
task_work_run+0x14e/0x250 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa7d/0x2be0 kernel/exit.c:878
do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
__do_sys_exit_group kernel/exit.c:1038 [inline]
__se_sys_exit_group kernel/exit.c:1036 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
INITIAL USE at:
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
class_spinlock_constructor include/linux/spinlock.h:561 [inline]
snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412
snd_timer_close+0x8b/0xf0 sound/core/timer.c:464
snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302
queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126
snd_seq_queue_delete+0x45/0x60 sound/core/seq/seq_queue.c:188
snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2526
delete_seq_queue.isra.0+0xc8/0x150 sound/core/seq/oss/seq_oss_init.c:371
odev_release+0x52/0x80 sound/core/seq/oss/seq_oss.c:144
__fput+0x270/0xb80 fs/file_table.c:422
task_work_run+0x14e/0x250 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa7d/0x2be0 kernel/exit.c:878
do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
__do_sys_exit_group kernel/exit.c:1038 [inline]
__se_sys_exit_group kernel/exit.c:1036 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
}
... key at: [<ffffffff949babc0>] __key.6+0x0/0x40
... acquired at:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
class_spinlock_irqsave_constructor include/linux/spinlock.h:574 [inline]
snd_timer_notify+0x111/0x3e0 sound/core/timer.c:1040
snd_pcm_timer_notify sound/core/pcm_native.c:622 [inline]
snd_pcm_post_start+0x272/0x350 sound/core/pcm_native.c:1459
snd_pcm_action_single+0x10a/0x150 sound/core/pcm_native.c:1289
snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370
__snd_pcm_lib_xfer+0x13f5/0x1ea0 sound/core/pcm_lib.c:2371
snd_pcm_oss_write3+0xd5/0x1e0 sound/core/oss/pcm_oss.c:1242
io_playback_transfer+0x273/0x300 sound/core/oss/io.c:47
snd_pcm_plug_write_transfer+0x2cd/0x410 sound/core/oss/pcm_plugin.c:630
snd_pcm_oss_write2+0x24f/0x3f0 sound/core/oss/pcm_oss.c:1374
snd_pcm_oss_sync1+0x1bf/0x510 sound/core/oss/pcm_oss.c:1616
snd_pcm_oss_sync+0x617/0x7f0 sound/core/oss/pcm_oss.c:1692
snd_pcm_oss_release+0x291/0x320 sound/core/oss/pcm_oss.c:2575
__fput+0x270/0xb80 fs/file_table.c:422
task_work_run+0x14e/0x250 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa7d/0x2be0 kernel/exit.c:878
do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
__do_sys_exit_group kernel/exit.c:1038 [inline]
__se_sys_exit_group kernel/exit.c:1036 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75

-> (&group->lock#2){..-.}-{2:2} {
IN-SOFTIRQ-W at:
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
_snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170
class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline]
snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904
dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1756
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773
__do_softirq+0x218/0x8de kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:633 [inline]
irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
default_idle+0xf/0x20 arch/x86/kernel/process.c:742
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x32c/0x3f0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313
common_startup_64+0x13e/0x148
INITIAL USE at:
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:376 [inline]
snd_pcm_group_lock_irq sound/core/pcm_native.c:97 [inline]
snd_pcm_stream_lock_irq sound/core/pcm_native.c:136 [inline]
class_pcm_stream_lock_irq_constructor include/sound/pcm.h:666 [inline]
snd_pcm_hw_params+0x151/0x1a30 sound/core/pcm_native.c:740
snd_pcm_kernel_ioctl+0x147/0x2d0 sound/core/pcm_native.c:3434
snd_pcm_oss_change_params_locked+0x146c/0x3aa0 sound/core/oss/pcm_oss.c:965
snd_pcm_oss_make_ready_locked+0xb7/0x130 sound/core/oss/pcm_oss.c:1187
snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1405 [inline]
snd_pcm_oss_write+0x4af/0xa10 sound/core/oss/pcm_oss.c:2796
vfs_write+0x298/0x1100 fs/read_write.c:588
ksys_write+0x12f/0x260 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
}
... key at: [<ffffffff949baf40>] __key.5+0x0/0x40
... acquired at:
mark_usage kernel/locking/lockdep.c:4567 [inline]
__lock_acquire+0x13d4/0x3b30 kernel/locking/lockdep.c:5091
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
_snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170
class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline]
snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904
dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1756
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773
__do_softirq+0x218/0x8de kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:633 [inline]
irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
default_idle+0xf/0x20 arch/x86/kernel/process.c:742
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x32c/0x3f0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313
common_startup_64+0x13e/0x148


stack backtrace:
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
print_irq_inversion_bug.part.0+0x3e9/0x5a0 kernel/locking/lockdep.c:4080
print_irq_inversion_bug kernel/locking/lockdep.c:4033 [inline]
check_usage_forwards kernel/locking/lockdep.c:4111 [inline]
mark_lock_irq kernel/locking/lockdep.c:4243 [inline]
mark_lock+0x574/0xc60 kernel/locking/lockdep.c:4678
mark_usage kernel/locking/lockdep.c:4567 [inline]
__lock_acquire+0x13d4/0x3b30 kernel/locking/lockdep.c:5091
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
_snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170
class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline]
snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904
dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1756
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773
__do_softirq+0x218/0x8de kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:633 [inline]
irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline]
RIP: 0010:default_idle+0xf/0x20 arch/x86/kernel/process.c:743
Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 41 34 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc90000187e08 EFLAGS: 00000242
RAX: 0000000000025cab RBX: 0000000000000002 RCX: ffffffff8ad255f9
RDX: 0000000000000000 RSI: ffffffff8b0cb740 RDI: ffffffff8b6e88a0
RBP: ffffed1002f52910 R08: 0000000000000001 R09: ffffed100d686fdd
R10: ffff88806b437eeb R11: 0000000000000000 R12: 0000000000000002
R13: ffff888017a94880 R14: ffffffff8f9e6f90 R15: 0000000000000000
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x32c/0x3f0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313
common_startup_64+0x13e/0x148
</TASK>
----------------
Code disassembly (best guess):
0: 4c 01 c7 add %r8,%rdi
3: 4c 29 c2 sub %r8,%rdx
6: e9 72 ff ff ff jmp 0xffffff7d
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 90 nop
1a: 90 nop
1b: f3 0f 1e fa endbr64
1f: 66 90 xchg %ax,%ax
21: 0f 00 2d e3 41 34 00 verw 0x3441e3(%rip) # 0x34420b
28: fb sti
29: f4 hlt
* 2a: fa cli <-- trapping instruction
2b: c3 ret
2c: cc int3
2d: cc int3
2e: cc int3
2f: cc int3
30: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1)
37: 00 00 00 00
3b: 90 nop
3c: 90 nop
3d: 90 nop
3e: 90 nop
3f: 90 nop


---
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.

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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
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[Takashi Iwai]

#syz fix: ALSA: timer: Fix missing irq-disable at closing

[Edward Adam Davis]

please test dl in _snd_pcm_stream_lock_irqsave

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 15b07d09c4b7..c501faa30040 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -409,7 +409,7 @@ static void snd_timer_close_locked(struct snd_timer_instance *timeri,
struct snd_timer *timer = timeri->timer;

if (timer) {
- guard(spinlock)(&timer->lock);
+ guard(spinlock_irqsave)(&timer->lock);
timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
}

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file sound/core/timer.c
Hunk #1 FAILED at 409.
1 out of 1 hunk FAILED



Tested on:

commit: 23956900 Merge tag 'v6.9-rc-smb3-server-fixes' of git:..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

kernel config: https://syzkaller.appspot.com/x/.config?x=aef2a55903e5791c
dashboard link: https://syzkaller.appspot.com/bug?extid=18840ef96e57b83b7fea
compiler:

patch: https://syzkaller.appspot.com/x/patch.diff?x=16d8023a180000

[Edward Adam Davis]

please test dl in _snd_pcm_stream_lock_irqsave

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git fe46a7dd189e

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+18840e...@syzkaller.appspotmail.com

Tested on:

commit: fe46a7dd Merge tag 'sound-6.9-rc1' of git://git.kernel..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1268783a180000

kernel config: https://syzkaller.appspot.com/x/.config?x=aef2a55903e5791c
dashboard link: https://syzkaller.appspot.com/bug?extid=18840ef96e57b83b7fea

compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=10928f15180000

Note: testing is done by a robot and is best-effort only.

[Edward Adam Davis]

[Syzbot reported]

swapper/2/0 just changed the state of lock:
ffff88802a304110 (&group->lock#2){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170
but this lock took another, SOFTIRQ-unsafe lock in the past:
(&timer->lock){+.+.}-{2:2}


and interrupts could create inverse lock ordering between them.


other info that might help us debug this:
Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&timer->lock);
local_irq_disable();
lock(&group->lock#2);
lock(&timer->lock);
<Interrupt>
lock(&group->lock#2);

*** DEADLOCK ***

[Fix]
Ensure that the context interrupt state is the same before and after using the
timer->lock.

Fixes: beb45974dd49 ("ALSA: timer: Use guard() for locking")
Reported-and-tested-by: syzbot+18840e...@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <ead...@qq.com>
---
sound/core/timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 15b07d09c4b7..c501faa30040 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -409,7 +409,7 @@ static void snd_timer_close_locked(struct snd_timer_instance *timeri,
struct snd_timer *timer = timeri->timer;

if (timer) {
- guard(spinlock)(&timer->lock);
+ guard(spinlock_irqsave)(&timer->lock);
timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
}

--
2.43.0

[Takashi Iwai]

This was already fixed in Linus tree commit
587d67fd929ad89801bcc429675bda90d53f6592.


thanks,

Takashi