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INFO: rcu detected stall in snd_vmidi_output_work (4)

Status: auto-obsoleted due to no activity on 2025/10/05 14:09
Subsystems: sound
[Documentation on labels]
First crash: 104d, last: 96d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in snd_vmidi_output_work (2) sound 1 1 300d 300d 0/29 auto-obsoleted due to no activity on 2025/03/14 23:00
upstream INFO: rcu detected stall in snd_vmidi_output_work (3) sound 1 1 199d 199d 0/29 auto-obsoleted due to no activity on 2025/06/23 21:57
upstream INFO: rcu detected stall in snd_vmidi_output_work sound 1 1 860d 860d 0/29 auto-obsoleted due to no activity on 2023/09/02 09:08

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9156/1:b..l P10414/1:b..l
rcu: 	(detected by 1, t=10505 jiffies, g=36617, q=327 ncpus=2)
task:syz.0.1113      state:R  running task     stack:28216 pid:10414 tgid:10414 ppid:5831   task_flags:0x40004c flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5401 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6790
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6970
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1765 [inline]
 zap_pmd_range mm/memory.c:1827 [inline]
 zap_pud_range mm/memory.c:1856 [inline]
 zap_p4d_range mm/memory.c:1877 [inline]
 unmap_page_range+0x106b/0x4350 mm/memory.c:1898
 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1941
 unmap_vmas+0x218/0x470 mm/memory.c:1985
 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284
 __mmput+0x12a/0x410 kernel/fork.c:1121
 mmput+0x62/0x70 kernel/fork.c:1144
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x7c4/0x2bd0 kernel/exit.c:952
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1114
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7d4a78e929
RSP: 002b:00007ffec6c9e8e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7d4a78e929
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffec6c9e94c R08: 0000000dc6c9e9df R09: 00000000000927c0
R10: 00000000000000e0 R11: 0000000000000246 R12: 00000000000000d9
R13: 00000000000927c0 R14: 0000000000060373 R15: 00007ffec6c9e9a0
 </TASK>
task:syz-executor    state:R  running task     stack:23496 pid:9156  tgid:9156  ppid:9141   task_flags:0x400140 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5401 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6790
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6970
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 copy_pte_range mm/memory.c:1206 [inline]
 copy_pmd_range mm/memory.c:1267 [inline]
 copy_pud_range mm/memory.c:1304 [inline]
 copy_p4d_range mm/memory.c:1328 [inline]
 copy_page_range+0x13c5/0x5740 mm/memory.c:1416
 dup_mmap+0xe88/0x21d0 mm/mmap.c:1838
 dup_mm kernel/fork.c:1477 [inline]
 copy_mm kernel/fork.c:1529 [inline]
 copy_process+0x4081/0x7650 kernel/fork.c:2169
 kernel_clone+0xfc/0x960 kernel/fork.c:2599
 __do_sys_clone+0xce/0x120 kernel/fork.c:2742
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f859a985193
RSP: 002b:00007ffd44d31858 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f859a985193
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055556f7a67d0 R11: 0000000000000246 R12: 0000000000000000
R13: 000055556f7b9590 R14: 000000000005ff3f R15: 00007ffd44d319f0
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g36617 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=24820
rcu: rcu_preempt kthread starved for 10501 jiffies! g36617 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:27784 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5401 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6790
 __schedule_loop kernel/sched/core.c:6868 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6883
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5971 Comm: kworker/0:2H Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_highpri snd_vmidi_output_work
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 db fc a0 f5 cc
RSP: 0018:ffffc90000007e38 EFLAGS: 00000046
RAX: 0000000000010001 RBX: ffff8880b8427d80 RCX: ffffffff81a8ebfe
RDX: ffff888036d64880 RSI: ffffffff81a8ef00 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880b8427c80
R13: 0000000000000001 R14: ffff888058695340 R15: ffffffff899aa520
FS:  0000000000000000(0000) GS:ffff888124718000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc28546ff98 CR3: 0000000046fce000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 trace_hrtimer_expire_entry include/trace/events/timer.h:259 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1758 [inline]
 __hrtimer_run_queues+0x890/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 16 c2 0d f6 48 89 df e8 fe 15 0e f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 95 33 fe f5 65 8b 05 2e ca 45 08 85 c0 74 16 5b
RSP: 0018:ffffc90005607b50 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff88814c53f138 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8de3106c RDI: ffffffff8c158660
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90a97357 R11: 0000000000000001 R12: ffff88814c53f138
R13: 0000000000000293 R14: 0000000000000001 R15: ffff88814bfb2c00
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 class_spinlock_irqsave_destructor include/linux/spinlock.h:585 [inline]
 snd_rawmidi_transmit+0xfb/0x140 sound/core/rawmidi.c:1486
 snd_vmidi_output_work+0x111/0x390 sound/core/seq/seq_virmidi.c:151
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/07 13:58 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in snd_vmidi_output_work
2025/06/28 20:08 upstream 35e261cd95dd fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in snd_vmidi_output_work
* Struck through repros no longer work on HEAD.