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INFO: rcu detected stall in snd_timer_user_ioctl_compat

Status: auto-obsoleted due to no activity on 2025/10/29 11:01
Subsystems: mm
[Documentation on labels]
First crash: 192d, last: 192d

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7107/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=18445, q=633831 ncpus=2)
task:syz.0.356       state:R  running task     stack:26728 pid:7107  tgid:7102  ppid:5859   task_flags:0x400040 flags:0x20004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5351 [inline]
 __schedule+0x1737/0x4d30 kernel/sched/core.c:6954
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7281
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:196
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 ab ae fc 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9001d9970d8 EFLAGS: 00000206
RAX: aea05cdff0dae600 RBX: 0000000000000000 RCX: aea05cdff0dae600
RDX: 0000000000000000 RSI: ffffffff8db664d4 RDI: ffffffff8be30a80
RBP: ffffffff8172cd05 R08: 0000000000000000 R09: ffffffff8172cd05
R10: ffffc9001d997298 R11: ffffffff81ac39b0 R12: 0000000000000002
R13: ffffffff8e13c5a0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
 discard_slab mm/slub.c:2752 [inline]
 __put_partials+0x156/0x1a0 mm/slub.c:3217
 put_cpu_partial+0x17c/0x250 mm/slub.c:3292
 __slab_free+0x2d5/0x3c0 mm/slub.c:4549
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:385
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4395
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 snd_timer_instance_new sound/core/timer.c:154 [inline]
 snd_timer_user_tselect sound/core/timer.c:1732 [inline]
 __snd_timer_user_ioctl+0x17da/0x3ff0 sound/core/timer.c:2265
 __snd_timer_user_ioctl_compat sound/core/timer_compat.c:101 [inline]
 snd_timer_user_ioctl_compat+0x41a/0xae0 sound/core/timer_compat.c:120
 __do_compat_sys_ioctl fs/ioctl.c:696 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:639 [inline]
 __ia32_compat_sys_ioctl+0x540/0x840 fs/ioctl.c:639
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f47539
RSP: 002b:00000000f504555c EFLAGS: 00000206 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000040345410
RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/31 10:52 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in snd_timer_user_ioctl_compat
* Struck through repros no longer work on HEAD.