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* [syzbot] [sound?] possible deadlock in snd_timer_close_locked
@ 2024-03-15 11:16 syzbot
  2024-03-15 11:51 ` Takashi Iwai
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: syzbot @ 2024-03-15 11:16 UTC (permalink / raw)
  To: linux-kernel, linux-sound, perex, syzkaller-bugs, tiwai, tiwai

Hello,

syzbot found the following issue on:

HEAD commit:    fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14cd9bd6180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a
dashboard link: https://syzkaller.appspot.com/bug?extid=f3bc6f8108108010a03d
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=149b2e86180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13a304a5180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/72ab73815344/disk-fe46a7dd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2d6d6b0d7071/vmlinux-fe46a7dd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/48e275e5478b/bzImage-fe46a7dd.xz

The issue was bisected to:

commit beb45974dd49068b24788bbfc2abe20d50503761
Author: Takashi Iwai <tiwai@suse.de>
Date:   Tue Feb 27 08:52:45 2024 +0000

    ALSA: timer: Use guard() for locking

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=100427b6180000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=120427b6180000
console output: https://syzkaller.appspot.com/x/log.txt?x=140427b6180000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f3bc6f8108108010a03d@syzkaller.appspotmail.com
Fixes: beb45974dd49 ("ALSA: timer: Use guard() for locking")

========================================================
WARNING: possible irq lock inversion dependency detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
--------------------------------------------------------
syz-executor504/5058 just changed the state of lock:
ffff8880293a4148 (&timer->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff8880293a4148 (&timer->lock){+.+.}-{2:2}, at: class_spinlock_constructor include/linux/spinlock.h:561 [inline]
ffff8880293a4148 (&timer->lock){+.+.}-{2:2}, at: snd_timer_close_locked+0x53/0x8d0 sound/core/timer.c:412
but this lock was taken by another, SOFTIRQ-safe lock in the past:
 (&group->lock#2){..-.}-{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 ***

3 locks held by syz-executor504/5058:
 #0: ffffffff8f2d3228 (register_mutex#4){+.+.}-{3:3}, at: odev_release+0x4e/0x80 sound/core/seq/oss/seq_oss.c:143
 #1: ffff88801f38f978 (&q->timer_mutex){+.+.}-{3:3}, at: queue_delete sound/core/seq/seq_queue.c:124 [inline]
 #1: ffff88801f38f978 (&q->timer_mutex){+.+.}-{3:3}, at: snd_seq_queue_delete+0x5b/0xf0 sound/core/seq/seq_queue.c:188
 #2: ffffffff8f2c1a68 (register_mutex){+.+.}-{3:3}, at: class_mutex_constructor include/linux/mutex.h:169 [inline]
 #2: ffffffff8f2c1a68 (register_mutex){+.+.}-{3:3}, at: snd_timer_close+0xa3/0x130 sound/core/timer.c:463

the shortest dependencies between 2nd lock and 1st lock:
 -> (&group->lock#2){..-.}-{2:2} {
    IN-SOFTIRQ-W at:
                      lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                      __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                      _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
                      class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline]
                      snd_pcm_period_elapsed+0x21/0x50 sound/core/pcm_lib.c:1904
                      dummy_hrtimer_callback+0x7f/0x180 sound/drivers/dummy.c:385
                      __run_hrtimer kernel/time/hrtimer.c:1692 [inline]
                      __hrtimer_run_queues+0x595/0xd00 kernel/time/hrtimer.c:1756
                      hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1773
                      __do_softirq+0x2bc/0x943 kernel/softirq.c:554
                      invoke_softirq kernel/softirq.c:428 [inline]
                      __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
                      irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
                      instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
                      sysvec_apic_timer_interrupt+0xa6/0xc0 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]
                      acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112
                      acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:707
                      cpuidle_enter_state+0x118/0x490 drivers/cpuidle/cpuidle.c:267
                      cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388
                      call_cpuidle kernel/sched/idle.c:155 [inline]
                      cpuidle_idle_call kernel/sched/idle.c:236 [inline]
                      do_idle+0x375/0x5d0 kernel/sched/idle.c:332
                      cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:430
                      rest_init+0x2e0/0x300 init/main.c:730
                      arch_call_rest_init+0xe/0x10 init/main.c:831
                      start_kernel+0x47a/0x500 init/main.c:1077
                      x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509
                      x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490
                      common_startup_64+0x13e/0x147
    INITIAL USE at:
                     lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                     __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
                     _raw_spin_lock_irq+0xd3/0x120 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+0x201/0x1ea0 sound/core/pcm_native.c:740
                     snd_pcm_oss_change_params_locked+0x20d5/0x3e00 sound/core/oss/pcm_oss.c:965
                     snd_pcm_oss_make_ready_locked sound/core/oss/pcm_oss.c:1187 [inline]
                     snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1515 [inline]
                     snd_pcm_oss_read+0x24c/0x940 sound/core/oss/pcm_oss.c:2773
                     do_loop_readv_writev fs/read_write.c:761 [inline]
                     vfs_readv+0x68f/0xa50 fs/read_write.c:934
                     do_readv+0x1b1/0x350 fs/read_write.c:994
                     do_syscall_64+0xfb/0x240
                     entry_SYSCALL_64_after_hwframe+0x6d/0x75
  }
  ... key      at: [<ffffffff9485f200>] snd_pcm_group_init.__key+0x0/0x20
  ... acquired at:
   lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
   _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
   class_spinlock_irqsave_constructor include/linux/spinlock.h:574 [inline]
   snd_timer_notify+0x103/0x3d0 sound/core/timer.c:1040
   snd_pcm_action sound/core/pcm_native.c:1370 [inline]
   snd_pcm_start+0x3fa/0x4c0 sound/core/pcm_native.c:1478
   __snd_pcm_lib_xfer+0x1af3/0x1e30 sound/core/pcm_lib.c:2301
   snd_pcm_oss_read3+0x3ea/0x600 sound/core/oss/pcm_oss.c:1281
   snd_pcm_plug_read_transfer+0x3a1/0x470 sound/core/oss/pcm_plugin.c:663
   snd_pcm_oss_read2+0x296/0x430 sound/core/oss/pcm_oss.c:1482
   snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1520 [inline]
   snd_pcm_oss_read+0x45b/0x940 sound/core/oss/pcm_oss.c:2773
   do_loop_readv_writev fs/read_write.c:761 [inline]
   vfs_readv+0x68f/0xa50 fs/read_write.c:934
   do_readv+0x1b1/0x350 fs/read_write.c:994
   do_syscall_64+0xfb/0x240
   entry_SYSCALL_64_after_hwframe+0x6d/0x75

-> (&timer->lock){+.+.}-{2:2} {
   HARDIRQ-ON-W at:
                    lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                    __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+0x53/0x8d0 sound/core/timer.c:412
                    snd_timer_close+0xae/0x130 sound/core/timer.c:464
                    snd_seq_timer_close+0xa9/0xe0 sound/core/seq/seq_timer.c:302
                    queue_delete sound/core/seq/seq_queue.c:126 [inline]
                    snd_seq_queue_delete+0x8f/0xf0 sound/core/seq/seq_queue.c:188
                    delete_seq_queue sound/core/seq/oss/seq_oss_init.c:371 [inline]
                    snd_seq_oss_release+0x1d3/0x310 sound/core/seq/oss/seq_oss_init.c:416
                    odev_release+0x56/0x80 sound/core/seq/oss/seq_oss.c:144
                    __fput+0x429/0x8a0 fs/file_table.c:422
                    task_work_run+0x24f/0x310 kernel/task_work.c:180
                    exit_task_work include/linux/task_work.h:38 [inline]
                    do_exit+0xa1b/0x27e0 kernel/exit.c:878
                    do_group_exit+0x207/0x2c0 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+0x3f/0x40 kernel/exit.c:1036
                    do_syscall_64+0xfb/0x240
                    entry_SYSCALL_64_after_hwframe+0x6d/0x75
   SOFTIRQ-ON-W at:
                    lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                    __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+0x53/0x8d0 sound/core/timer.c:412
                    snd_timer_close+0xae/0x130 sound/core/timer.c:464
                    snd_seq_timer_close+0xa9/0xe0 sound/core/seq/seq_timer.c:302
                    queue_delete sound/core/seq/seq_queue.c:126 [inline]
                    snd_seq_queue_delete+0x8f/0xf0 sound/core/seq/seq_queue.c:188
                    delete_seq_queue sound/core/seq/oss/seq_oss_init.c:371 [inline]
                    snd_seq_oss_release+0x1d3/0x310 sound/core/seq/oss/seq_oss_init.c:416
                    odev_release+0x56/0x80 sound/core/seq/oss/seq_oss.c:144
                    __fput+0x429/0x8a0 fs/file_table.c:422
                    task_work_run+0x24f/0x310 kernel/task_work.c:180
                    exit_task_work include/linux/task_work.h:38 [inline]
                    do_exit+0xa1b/0x27e0 kernel/exit.c:878
                    do_group_exit+0x207/0x2c0 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+0x3f/0x40 kernel/exit.c:1036
                    do_syscall_64+0xfb/0x240
                    entry_SYSCALL_64_after_hwframe+0x6d/0x75
   INITIAL USE at:
                   lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                   _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
                   class_spinlock_irqsave_constructor include/linux/spinlock.h:574 [inline]
                   snd_timer_notify+0x103/0x3d0 sound/core/timer.c:1040
                   snd_pcm_action sound/core/pcm_native.c:1370 [inline]
                   snd_pcm_start+0x3fa/0x4c0 sound/core/pcm_native.c:1478
                   __snd_pcm_lib_xfer+0x1af3/0x1e30 sound/core/pcm_lib.c:2301
                   snd_pcm_oss_read3+0x3ea/0x600 sound/core/oss/pcm_oss.c:1281
                   snd_pcm_plug_read_transfer+0x3a1/0x470 sound/core/oss/pcm_plugin.c:663
                   snd_pcm_oss_read2+0x296/0x430 sound/core/oss/pcm_oss.c:1482
                   snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1520 [inline]
                   snd_pcm_oss_read+0x45b/0x940 sound/core/oss/pcm_oss.c:2773
                   do_loop_readv_writev fs/read_write.c:761 [inline]
                   vfs_readv+0x68f/0xa50 fs/read_write.c:934
                   do_readv+0x1b1/0x350 fs/read_write.c:994
                   do_syscall_64+0xfb/0x240
                   entry_SYSCALL_64_after_hwframe+0x6d/0x75
 }
 ... key      at: [<ffffffff9485efe0>] snd_timer_new.__key+0x0/0x20
 ... acquired at:
   mark_lock+0x223/0x350 kernel/locking/lockdep.c:4678
   __lock_acquire+0x116e/0x1fd0 kernel/locking/lockdep.c:5091
   lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
   __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+0x53/0x8d0 sound/core/timer.c:412
   snd_timer_close+0xae/0x130 sound/core/timer.c:464
   snd_seq_timer_close+0xa9/0xe0 sound/core/seq/seq_timer.c:302
   queue_delete sound/core/seq/seq_queue.c:126 [inline]
   snd_seq_queue_delete+0x8f/0xf0 sound/core/seq/seq_queue.c:188
   delete_seq_queue sound/core/seq/oss/seq_oss_init.c:371 [inline]
   snd_seq_oss_release+0x1d3/0x310 sound/core/seq/oss/seq_oss_init.c:416
   odev_release+0x56/0x80 sound/core/seq/oss/seq_oss.c:144
   __fput+0x429/0x8a0 fs/file_table.c:422
   task_work_run+0x24f/0x310 kernel/task_work.c:180
   exit_task_work include/linux/task_work.h:38 [inline]
   do_exit+0xa1b/0x27e0 kernel/exit.c:878
   do_group_exit+0x207/0x2c0 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+0x3f/0x40 kernel/exit.c:1036
   do_syscall_64+0xfb/0x240
   entry_SYSCALL_64_after_hwframe+0x6d/0x75


stack backtrace:
CPU: 0 PID: 5058 Comm: syz-executor504 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 mark_lock_irq+0x867/0xc20 kernel/locking/lockdep.c:4236
 mark_lock+0x223/0x350 kernel/locking/lockdep.c:4678
 __lock_acquire+0x116e/0x1fd0 kernel/locking/lockdep.c:5091
 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
 __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+0x53/0x8d0 sound/core/timer.c:412
 snd_timer_close+0xae/0x130 sound/core/timer.c:464
 snd_seq_timer_close+0xa9/0xe0 sound/core/seq/seq_timer.c:302
 queue_delete sound/core/seq/seq_queue.c:126 [inline]
 snd_seq_queue_delete+0x8f/0xf0 sound/core/seq/seq_queue.c:188
 delete_seq_queue sound/core/seq/oss/seq_oss_init.c:371 [inline]
 snd_seq_oss_release+0x1d3/0x310 sound/core/seq/oss/seq_oss_init.c:416
 odev_release+0x56/0x80 sound/core/seq/oss/seq_oss.c:144
 __fput+0x429/0x8a0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa1b/0x27e0 kernel/exit.c:878
 do_group_exit+0x207/0x2c0 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+0x3f/0x40 kernel/exit.c:1036
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f0910103b89
Code: Unable to access opcode bytes at 0x7f0910103b5f.
RSP: 002b:00007ffc7b2de668 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0910103b89
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f091017e290 R08: ffffffffffffffb8 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f091017e290
R13: 0000000000000000 R14: 00007f091017ece0 R15: 00007f09100d4df0
 </TASK>


---
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 syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

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
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [sound?] possible deadlock in snd_timer_close_locked
  2024-03-15 11:16 [syzbot] [sound?] possible deadlock in snd_timer_close_locked syzbot
@ 2024-03-15 11:51 ` Takashi Iwai
  2024-03-15 13:05 ` Hillf Danton
  2024-03-16  8:52 ` Hillf Danton
  2 siblings, 0 replies; 6+ messages in thread
From: Takashi Iwai @ 2024-03-15 11:51 UTC (permalink / raw)
  To: syzbot; +Cc: linux-kernel, linux-sound, perex, syzkaller-bugs, tiwai, tiwai

#syz dup: [syzbot] [sound?] possible deadlock in snd_pcm_period_elapsed (4)

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [sound?] possible deadlock in snd_timer_close_locked
  2024-03-15 11:16 [syzbot] [sound?] possible deadlock in snd_timer_close_locked syzbot
  2024-03-15 11:51 ` Takashi Iwai
@ 2024-03-15 13:05 ` Hillf Danton
  2024-03-15 13:34   ` syzbot
  2024-03-16  8:52 ` Hillf Danton
  2 siblings, 1 reply; 6+ messages in thread
From: Hillf Danton @ 2024-03-15 13:05 UTC (permalink / raw)
  To: syzbot; +Cc: linux-kernel, syzkaller-bugs, tiwai

On Fri, 15 Mar 2024 04:16:27 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13a304a5180000

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

--- x/sound/core/timer.c
+++ y/sound/core/timer.c
@@ -409,8 +409,9 @@ static void snd_timer_close_locked(struc
 	struct snd_timer *timer = timeri->timer;
 
 	if (timer) {
-		guard(spinlock)(&timer->lock);
+		spin_lock_irq(&timer->lock);
 		timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
+		spin_unlock_irq(&timer->lock);
 	}
 
 	if (!list_empty(&timeri->open_list)) {
--

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [sound?] possible deadlock in snd_timer_close_locked
  2024-03-15 13:05 ` Hillf Danton
@ 2024-03-15 13:34   ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2024-03-15 13:34 UTC (permalink / raw)
  To: hdanton, linux-kernel, syzkaller-bugs, tiwai

Hello,

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

: registered new interface driver port100
[    7.829002][    T1] usbcore: registered new interface driver nfcmrvl
[    7.837538][    T1] Loading iSCSI transport class v2.0-870.
[    7.856507][    T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
[    7.866977][    T1] ------------[ cut here ]------------
[    7.868232][    T1] refcount_t: decrement hit 0; leaking memory.
[    7.869519][    T1] WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0
[    7.870990][    T1] Modules linked in:
[    7.871688][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-syzkaller-09791-ge5eb28f6d1af-dirty #0
[    7.876326][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
[    7.878700][    T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[    7.879754][    T1] Code: b2 00 00 00 e8 27 5a f7 fc 5b 5d c3 cc cc cc cc e8 1b 5a f7 fc c6 05 f6 81 d3 0a 01 90 48 c7 c7 e0 a7 fd 8b e8 47 2e ba fc 90 <0f> 0b 90 90 eb d9 e8 fb 59 f7 fc c6 05 d3 81 d3 0a 01 90 48 c7 c7
[    7.882789][    T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[    7.884154][    T1] RAX: 427762defa97e000 RBX: ffff888020edeb2c RCX: ffff8880166c8000
[    7.885354][    T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[    7.886832][    T1] RBP: 0000000000000004 R08: ffffffff8157cf32 R09: fffffbfff1bf9650
[    7.888655][    T1] R10: dffffc0000000000 R11: fffffbfff1bf9650 R12: ffffea0000843dc0
[    7.889916][    T1] R13: ffffea0000843dc8 R14: 1ffffd40001087b9 R15: 0000000000000000
[    7.893126][    T1] FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
[    7.895114][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.896277][    T1] CR2: ffff88823ffff000 CR3: 000000000df32000 CR4: 00000000003506f0
[    7.897638][    T1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    7.900434][    T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    7.902939][    T1] Call Trace:
[    7.904000][    T1]  <TASK>
[    7.904699][    T1]  ? __warn+0x163/0x4b0
[    7.905611][    T1]  ? refcount_warn_saturate+0xfa/0x1d0
[    7.906808][    T1]  ? report_bug+0x2b3/0x500
[    7.907725][    T1]  ? refcount_warn_saturate+0xfa/0x1d0
[    7.908788][    T1]  ? handle_bug+0x3e/0x70
[    7.909996][    T1]  ? exc_invalid_op+0x1a/0x50
[    7.910753][    T1]  ? asm_exc_invalid_op+0x1a/0x20
[    7.911517][    T1]  ? __warn_printk+0x292/0x360
[    7.912828][    T1]  ? refcount_warn_saturate+0xfa/0x1d0
[    7.914043][    T1]  ? refcount_warn_saturate+0xf9/0x1d0
[    7.914947][    T1]  __free_pages_ok+0xc36/0xd60
[    7.916124][    T1]  make_alloc_exact+0xa3/0xf0
[    7.917078][    T1]  vring_alloc_queue_split+0x20a/0x600
[    7.918018][    T1]  ? __pfx_vring_alloc_queue_split+0x10/0x10
[    7.919870][    T1]  ? vp_find_vqs+0x4c/0x4e0
[    7.920839][    T1]  ? virtscsi_probe+0x3ea/0xf60
[    7.921640][    T1]  ? virtio_dev_probe+0x991/0xaf0
[    7.922633][    T1]  ? really_probe+0x29e/0xc50
[    7.923595][    T1]  ? driver_probe_device+0x50/0x430
[    7.925027][    T1]  vring_create_virtqueue_split+0xc6/0x310
[    7.926040][    T1]  ? ret_from_fork+0x4b/0x80
[    7.927657][    T1]  ? __pfx_vring_create_virtqueue_split+0x10/0x10
[    7.929661][    T1]  vring_create_virtqueue+0xca/0x110
[    7.930785][    T1]  ? __pfx_vp_notify+0x10/0x10
[    7.931677][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    7.932523][    T1]  setup_vq+0xe9/0x2d0
[    7.933148][    T1]  ? __pfx_vp_notify+0x10/0x10
[    7.934298][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    7.936631][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    7.938514][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    7.939708][    T1]  vp_setup_vq+0xbf/0x330
[    7.940480][    T1]  ? __pfx_vp_config_changed+0x10/0x10
[    7.941952][    T1]  ? ioread16+0x2f/0x90
[    7.943383][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    7.945869][    T1]  vp_find_vqs_msix+0x8b2/0xc80
[    7.946930][    T1]  vp_find_vqs+0x4c/0x4e0
[    7.948366][    T1]  virtscsi_init+0x8db/0xd00
[    7.949444][    T1]  ? __pfx_virtscsi_init+0x10/0x10
[    7.950722][    T1]  ? __pfx_default_calc_sets+0x10/0x10
[    7.952485][    T1]  ? scsi_host_alloc+0xa57/0xea0
[    7.954177][    T1]  ? vp_get+0xfd/0x140
[    7.955309][    T1]  virtscsi_probe+0x3ea/0xf60
[    7.956670][    T1]  ? __pfx_virtscsi_probe+0x10/0x10
[    7.958350][    T1]  ? virtqueue_dma_mapping_error+0xd/0x80
[    7.960113][    T1]  ? __pfx_vp_set_status+0x10/0x10
[    7.961499][    T1]  ? vp_set_status+0x1a/0x40
[    7.962431][    T1]  ? virtio_no_restricted_mem_acc+0x9/0x10
[    7.964349][    T1]  ? virtio_features_ok+0x10c/0x270
[    7.965595][    T1]  virtio_dev_probe+0x991/0xaf0
[    7.966818][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[    7.967921][    T1]  really_probe+0x29e/0xc50
[    7.968593][    T1]  __driver_probe_device+0x1a2/0x3e0
[    7.969535][    T1]  driver_probe_device+0x50/0x430
[    7.970634][    T1]  __driver_attach+0x45f/0x710
[    7.971732][    T1]  ? __pfx___driver_attach+0x10/0x10
[    7.973000][    T1]  bus_for_each_dev+0x239/0x2b0
[    7.974208][    T1]  ? __pfx___driver_attach+0x10/0x10
[    7.975425][    T1]  ? __pfx_bus_for_each_dev+0x10/0x10
[    7.976355][    T1]  ? do_raw_spin_unlock+0x13c/0x8b0
[    7.977543][    T1]  bus_add_driver+0x347/0x620
[    7.979682][    T1]  driver_register+0x23a/0x320
[    7.981056][    T1]  ? __pfx_virtio_scsi_init+0x10/0x10
[    7.982342][    T1]  virtio_scsi_init+0x65/0xe0
[    7.983870][    T1]  ? __pfx_virtio_scsi_init+0x10/0x10
[    7.985269][    T1]  do_one_initcall+0x238/0x830
[    7.986554][    T1]  ? __pfx_virtio_scsi_init+0x10/0x10
[    7.987867][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    7.989039][    T1]  ? lockdep_hardirqs_on_prepare+0x43d/0x780
[    7.990465][    T1]  ? __pfx_parse_args+0x10/0x10
[    7.991527][    T1]  ? do_initcalls+0x1c/0x80
[    7.992292][    T1]  ? rcu_is_watching+0x15/0xb0
[    7.993265][    T1]  do_initcall_level+0x157/0x210
[    7.994180][    T1]  do_initcalls+0x3f/0x80
[    7.994906][    T1]  kernel_init_freeable+0x435/0x5d0
[    7.995937][    T1]  ? __pfx_kernel_init_freeable+0x10/0x10
[    7.996856][    T1]  ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[    7.997739][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.999001][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.999909][    T1]  ? __pfx_kernel_init+0x10/0x10
[    8.000823][    T1]  kernel_init+0x1d/0x2b0
[    8.001451][    T1]  ret_from_fork+0x4b/0x80
[    8.002268][    T1]  ? __pfx_kernel_init+0x10/0x10
[    8.003408][    T1]  ret_from_fork_asm+0x1a/0x30
[    8.004122][    T1]  </TASK>
[    8.005036][    T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[    8.006846][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-syzkaller-09791-ge5eb28f6d1af-dirty #0
[    8.009117][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
[    8.011687][    T1] Call Trace:
[    8.012892][    T1]  <TASK>
[    8.013386][    T1]  dump_stack_lvl+0x241/0x360
[    8.013386][    T1]  ? __pfx_dump_stack_lvl+0x10/0x10
[    8.013386][    T1]  ? __pfx__printk+0x10/0x10
[    8.013386][    T1]  ? _printk+0xd5/0x120
[    8.013386][    T1]  ? vscnprintf+0x5d/0x90
[    8.013386][    T1]  panic+0x349/0x860
[    8.013386][    T1]  ? __warn+0x172/0x4b0
[    8.013386][    T1]  ? __pfx_panic+0x10/0x10
[    8.013386][    T1]  ? show_trace_log_lvl+0x4e6/0x520
[    8.013386][    T1]  ? ret_from_fork_asm+0x1a/0x30
[    8.013386][    T1]  __warn+0x31e/0x4b0
[    8.013386][    T1]  ? refcount_warn_saturate+0xfa/0x1d0
[    8.013386][    T1]  report_bug+0x2b3/0x500
[    8.013386][    T1]  ? refcount_warn_saturate+0xfa/0x1d0
[    8.013386][    T1]  handle_bug+0x3e/0x70
[    8.013386][    T1]  exc_invalid_op+0x1a/0x50
[    8.013386][    T1]  asm_exc_invalid_op+0x1a/0x20
[    8.013386][    T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[    8.013386][    T1] Code: b2 00 00 00 e8 27 5a f7 fc 5b 5d c3 cc cc cc cc e8 1b 5a f7 fc c6 05 f6 81 d3 0a 01 90 48 c7 c7 e0 a7 fd 8b e8 47 2e ba fc 90 <0f> 0b 90 90 eb d9 e8 fb 59 f7 fc c6 05 d3 81 d3 0a 01 90 48 c7 c7
[    8.013386][    T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[    8.013386][    T1] RAX: 427762defa97e000 RBX: ffff888020edeb2c RCX: ffff8880166c8000
[    8.013386][    T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[    8.013386][    T1] RBP: 0000000000000004 R08: ffffffff8157cf32 R09: fffffbfff1bf9650
[    8.013386][    T1] R10: dffffc0000000000 R11: fffffbfff1bf9650 R12: ffffea0000843dc0
[    8.013386][    T1] R13: ffffea0000843dc8 R14: 1ffffd40001087b9 R15: 0000000000000000
[    8.013386][    T1]  ? __warn_printk+0x292/0x360
[    8.013386][    T1]  ? refcount_warn_saturate+0xf9/0x1d0
[    8.013386][    T1]  __free_pages_ok+0xc36/0xd60
[    8.013386][    T1]  make_alloc_exact+0xa3/0xf0
[    8.013386][    T1]  vring_alloc_queue_split+0x20a/0x600
[    8.013386][    T1]  ? __pfx_vring_alloc_queue_split+0x10/0x10
[    8.013386][    T1]  ? vp_find_vqs+0x4c/0x4e0
[    8.013386][    T1]  ? virtscsi_probe+0x3ea/0xf60
[    8.013386][    T1]  ? virtio_dev_probe+0x991/0xaf0
[    8.013386][    T1]  ? really_probe+0x29e/0xc50
[    8.013386][    T1]  ? driver_probe_device+0x50/0x430
[    8.013386][    T1]  vring_create_virtqueue_split+0xc6/0x310
[    8.013386][    T1]  ? ret_from_fork+0x4b/0x80
[    8.063354][    T1]  ? __pfx_vring_create_virtqueue_split+0x10/0x10
[    8.063354][    T1]  vring_create_virtqueue+0xca/0x110
[    8.063354][    T1]  ? __pfx_vp_notify+0x10/0x10
[    8.063354][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    8.063354][    T1]  setup_vq+0xe9/0x2d0
[    8.063354][    T1]  ? __pfx_vp_notify+0x10/0x10
[    8.063354][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    8.063354][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    8.063354][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    8.063354][    T1]  vp_setup_vq+0xbf/0x330
[    8.063354][    T1]  ? __pfx_vp_config_changed+0x10/0x10
[    8.063354][    T1]  ? ioread16+0x2f/0x90
[    8.063354][    T1]  ? __pfx_virtscsi_ctrl_done+0x10/0x10
[    8.063354][    T1]  vp_find_vqs_msix+0x8b2/0xc80
[    8.063354][    T1]  vp_find_vqs+0x4c/0x4e0
[    8.063354][    T1]  virtscsi_init+0x8db/0xd00
[    8.063354][    T1]  ? __pfx_virtscsi_init+0x10/0x10
[    8.063354][    T1]  ? __pfx_default_calc_sets+0x10/0x10
[    8.063354][    T1]  ? scsi_host_alloc+0xa57/0xea0
[    8.063354][    T1]  ? vp_get+0xfd/0x140
[    8.063354][    T1]  virtscsi_probe+0x3ea/0xf60
[    8.063354][    T1]  ? __pfx_virtscsi_probe+0x10/0x10
[    8.063354][    T1]  ? virtqueue_dma_mapping_error+0xd/0x80
[    8.063354][    T1]  ? __pfx_vp_set_status+0x10/0x10
[    8.063354][    T1]  ? vp_set_status+0x1a/0x40
[    8.063354][    T1]  ? virtio_no_restricted_mem_acc+0x9/0x10
[    8.063354][    T1]  ? virtio_features_ok+0x10c/0x270
[    8.063354][    T1]  virtio_dev_probe+0x991/0xaf0
[    8.063354][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[    8.063354][    T1]  really_probe+0x29e/0xc50
[    8.063354][    T1]  __driver_probe_device+0x1a2/0x3e0
[    8.063354][    T1]  driver_probe_device+0x50/0x430
[    8.063354][    T1]  __driver_attach+0x45f/0x710
[    8.063354][    T1]  ? __pfx___driver_attach+0x10/0x10
[    8.063354][    T1]  bus_for_each_dev+0x239/0x2b0
[    8.063354][    T1]  ? __pfx___driver_attach+0x10/0x10
[    8.063354][    T1]  ? __pfx_bus_for_each_dev+0x10/0x10
[    8.063354][    T1]  ? do_raw_spin_unlock+0x13c/0x8b0
[    8.063354][    T1]  bus_add_driver+0x347/0x620
[    8.063354][    T1]  driver_register+0x23a/0x320
[    8.063354][    T1]  ? __pfx_virtio_scsi_init+0x10/0x10
[    8.063354][    T1]  virtio_scsi_init+0x65/0xe0
[    8.063354][    T1]  ? __pfx_virtio_scsi_init+0x10/0x10
[    8.063354][    T1]  do_one_initcall+0x238/0x830
[    8.063354][    T1]  ? __pfx_virtio_scsi_init+0x10/0x10
[    8.063354][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    8.063354][    T1]  ? lockdep_hardirqs_on_prepare+0x43d/0x780
[    8.063354][    T1]  ? __pfx_parse_args+0x10/0x10
[    8.113373][    T1]  ? do_initcalls+0x1c/0x80
[    8.113373][    T1]  ? rcu_is_watching+0x15/0xb0
[    8.113373][    T1]  do_initcall_level+0x157/0x210
[    8.113373][    T1]  do_initcalls+0x3f/0x80
[    8.113373][    T1]  kernel_init_freeable+0x435/0x5d0
[    8.113373][    T1]  ? __pfx_kernel_init_freeable+0x10/0x10
[    8.113373][    T1]  ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[    8.113373][    T1]  ? __pfx_kernel_init+0x10/0x10
[    8.113373][    T1]  ? __pfx_kernel_init+0x10/0x10
[    8.113373][    T1]  ? __pfx_kernel_init+0x10/0x10
[    8.113373][    T1]  kernel_init+0x1d/0x2b0
[    8.113373][    T1]  ret_from_fork+0x4b/0x80
[    8.113373][    T1]  ? __pfx_kernel_init+0x10/0x10
[    8.113373][    T1]  ret_from_fork_asm+0x1a/0x30
[    8.113373][    T1]  </TASK>
[    8.113373][    T1] Kernel Offset: disabled
[    8.113373][    T1] Rebooting in 86400 seconds..


syzkaller build log:
go env (err=<nil>)
GO111MODULE='auto'
GOARCH='amd64'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.4'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2569298022=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at d615901c7
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' ./sys/syz-sysgen | grep -q false || go install ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=d615901c739a765329b688494cee2f8e1b5037cb -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240314-145638'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-fuzzer github.com/google/syzkaller/syz-fuzzer
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=d615901c739a765329b688494cee2f8e1b5037cb -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240314-145638'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=d615901c739a765329b688494cee2f8e1b5037cb -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240314-145638'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-stress github.com/google/syzkaller/tools/syz-stress
mkdir -p ./bin/linux_amd64
gcc -o ./bin/linux_amd64/syz-executor executor/executor.cc \
	-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -fpermissive -w -DGOOS_linux=1 -DGOARCH_amd64=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"d615901c739a765329b688494cee2f8e1b5037cb\"


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=161a7959180000


Tested on:

commit:         e5eb28f6 Merge tag 'mm-nonmm-stable-2024-03-14-09-36' ..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
kernel config:  https://syzkaller.appspot.com/x/.config?x=839e3be5d86ffd1d
dashboard link: https://syzkaller.appspot.com/bug?extid=f3bc6f8108108010a03d
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13298231180000


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [sound?] possible deadlock in snd_timer_close_locked
  2024-03-15 11:16 [syzbot] [sound?] possible deadlock in snd_timer_close_locked syzbot
  2024-03-15 11:51 ` Takashi Iwai
  2024-03-15 13:05 ` Hillf Danton
@ 2024-03-16  8:52 ` Hillf Danton
  2024-03-16  9:11   ` syzbot
  2 siblings, 1 reply; 6+ messages in thread
From: Hillf Danton @ 2024-03-16  8:52 UTC (permalink / raw)
  To: syzbot; +Cc: linux-kernel, syzkaller-bugs

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

--- x/sound/core/timer.c
+++ y/sound/core/timer.c
@@ -409,8 +409,9 @@ static void snd_timer_close_locked(struc
 	struct snd_timer *timer = timeri->timer;
 
 	if (timer) {
-		guard(spinlock)(&timer->lock);
+		spin_lock_irq(&timer->lock);
 		timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
+		spin_unlock_irq(&timer->lock);
 	}
 
 	if (!list_empty(&timeri->open_list)) {
--

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [sound?] possible deadlock in snd_timer_close_locked
  2024-03-16  8:52 ` Hillf Danton
@ 2024-03-16  9:11   ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2024-03-16  9:11 UTC (permalink / raw)
  To: hdanton, linux-kernel, syzkaller-bugs

Hello,

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

Reported-and-tested-by: syzbot+f3bc6f8108108010a03d@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=142f5185180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a
dashboard link: https://syzkaller.appspot.com/bug?extid=f3bc6f8108108010a03d
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17ff06be180000

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

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2024-03-16  9:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-03-15 11:16 [syzbot] [sound?] possible deadlock in snd_timer_close_locked syzbot
2024-03-15 11:51 ` Takashi Iwai
2024-03-15 13:05 ` Hillf Danton
2024-03-15 13:34   ` syzbot
2024-03-16  8:52 ` Hillf Danton
2024-03-16  9:11   ` syzbot

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