INFO: rcu detected stall in snd_seq_release

Status: auto-obsoleted due to no activity on 2026/08/08 06:11
Subsystems: sound
Labels: prio:low
[Documentation on labels]
First crash: 92d, last: 92d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
45f5052f assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: rcu detected stall in snd_seq_release 2026/05/24 08:37 2026/05/24 08:37 2026/05/24 09:18 c69befb3

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P30414/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=258369, q=2215 ncpus=2)
task:syz.3.5831      state:R  running task     stack:25592 pid:30414 tgid:30414 ppid:24917  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline]
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0x25/0x3c0 kernel/locking/lockdep.c:5879
Code: 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 e0 4d 97 11 48 89 44 24 28 <0f> 1f 44 00 00 65 8b 05 e3 4d 97 11 83 f8 08 0f 83 56 02 00 00 89
RSP: 0018:ffffc9000343f790 EFLAGS: 00000286
RAX: 774e78f30c5add00 RBX: ffffc9000343f901 RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8176f256 RDI: ffffffff8e95cd60
RBP: dffffc0000000000 R08: ffffc9000343f927 R09: 0000000000000000
R10: ffffc9000343f918 R11: fffff52000687f25 R12: ffffc9000343fd08
R13: ffffffff8176f256 R14: ffffffff8e95cd60 R15: ffffffff8176f256
 rcu_lock_release include/linux/rcupdate.h:310 [inline]
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
 unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6250 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6565
 snd_seq_pool_delete+0xa5/0xd0 sound/core/seq/seq_memory.c:547
 snd_seq_fifo_delete+0x103/0x150 sound/core/seq/seq_fifo.c:74
 snd_seq_release+0x75/0xc0 sound/core/seq/seq_clientmgr.c:356
 __fput+0x44f/0xa60 fs/file_table.c:510
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9cd8f9cdd9
RSP: 002b:00007f9cd933fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f9cd9217da0 RCX: 00007f9cd8f9cdd9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f9cd9217da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f9cd9217cb0 R11: 0000000000000246 R12: 000000000014a961
R13: 00007f9cd921609c R14: 000000000014a8ce R15: 00007f9cd9216090
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/10 06:11 upstream 1bfaee9d3351 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in snd_seq_release
* Struck through repros no longer work on HEAD.