rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=5cbc/1/0x4000000000000000 softirq=57176/57177 fqs=0
rcu: 	(detected by 1, t=10506 jiffies, g=39637, q=77 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11726 Comm: syz.5.1370 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:102 [inline]
RIP: 0010:do_raw_spin_unlock+0xa0/0x230 kernel/locking/spinlock_debug.c:141
Code: d2 0f 85 6c 01 00 00 8b 03 85 c0 0f 84 f5 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 63 10 4c 89 e2 48 c1 ea 03 80 3c 02 00 <0f> 85 67 01 00 00 65 48 8b 05 0a 68 18 12 48 39 43 10 0f 85 d8 00
RSP: 0018:ffffc90000007d18 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffffffff9aea7020 RCX: ffffffff819a47b3
RDX: 1ffffffff35d4e06 RSI: 0000000000000004 RDI: ffffffff9aea7020
RBP: 0000000000000002 R08: 0000000000000000 R09: fffffbfff35d4e04
R10: ffffffff9aea7023 R11: ffff88801ef38b30 R12: ffffffff9aea7030
R13: dffffc0000000000 R14: ffff88803393c300 R15: 1ffff92000000fac
FS:  00007ff4df0816c0(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1913402d77 CR3: 00000000341fd000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
 _raw_spin_unlock_irqrestore+0x22/0x80 kernel/locking/spinlock.c:194
 debug_object_deactivate+0x1ec/0x3a0 lib/debugobjects.c:888
 debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline]
 debug_deactivate kernel/time/hrtimer.c:483 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1745 [inline]
 __hrtimer_run_queues+0x46f/0xc40 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
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 c6 0d 1f f6 48 89 df e8 7e 60 1f f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 85 63 0f f6 65 8b 05 2e c9 37 08 85 c0 74 16 5b
RSP: 0018:ffffc9000460fa80 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff88814c564138 RCX: ffffffff81c707ef
RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: ffffffff8bf2b400
RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088b4d7 R11: ffff88801ef38b30 R12: 0000000000000001
R13: 000000000000dd44 R14: dffffc0000000000 R15: 0000000000001000
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 snd_rawmidi_kernel_write1+0x488/0x8a0 sound/core/rawmidi.c:1559
 snd_rawmidi_write+0x26e/0xc10 sound/core/rawmidi.c:1629
 do_loop_readv_writev fs/read_write.c:850 [inline]
 do_loop_readv_writev fs/read_write.c:835 [inline]
 vfs_writev+0x5df/0xde0 fs/read_write.c:1059
 do_writev+0x28c/0x340 fs/read_write.c:1103
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff4de18f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff4df081038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007ff4de3e5fa0 RCX: 00007ff4de18f749
RDX: 0000000000000002 RSI: 0000200000000840 RDI: 000000000000000e
RBP: 00007ff4de213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff4de3e6038 R14: 00007ff4de3e5fa0 R15: 00007fff528dbb58
 </TASK>
rcu: rcu_preempt kthread starved for 10506 jiffies! g39637 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:28328 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 66 68 58 00 48 89 df 5b e9 4d 1b 5e 00 be 03 00 00 00 5b e9 12 dd ed 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 34 24 65 48 8b 15 98 c9 f3 11 65 8b 05 a9 c9 f3
RSP: 0018:ffffc900001579b0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000002180 RCX: ffffffff81a9c0b8
RDX: ffff88801da88000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88801da88b30 R12: 0000000000000000
R13: ffffc90000157b58 R14: fffff5200002af6f R15: dffffc0000000000
 get_timer_cpu_base kernel/time/timer.c:916 [inline]
 get_timer_base kernel/time/timer.c:944 [inline]
 lock_timer_base+0xc2/0x1d0 kernel/time/timer.c:1003
 __mod_timer+0x425/0xd30 kernel/time/timer.c:1085
 add_timer+0x62/0x90 kernel/time/timer.c:1249
 schedule_timeout+0x11e/0x290 kernel/time/sleep_timeout.c:98
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: c6 5f 02 c3 cc cc cc cc 0f 1f 00 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 13 49 12 00 fb f4 <e9> cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 0000000001934e77 RBX: 0000000000000001 RCX: ffffffff8b7816d9
RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: ffffffff8bf2b400
RBP: ffffed1003b56498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801dab2ff0 R12: 0000000000000001
R13: ffff88801dab24c0 R14: ffffffff9088b4d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c40d558 CR3: 000000005a9c7000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x38d/0x510 kernel/sched/idle.c:332
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>