rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15085/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=72225, q=61 ncpus=2)
task:syz.1.2584 state:R running task stack:24328 pid:15085 tgid:15084 ppid:5822 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:deref_stack_reg+0x1/0x230 arch/x86/kernel/unwind_orc.c:402
Code: 24 18 e8 32 f5 ae 00 48 8b 4c 24 18 e9 f2 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 20 48 89 54 24 18 49 89 f0 49
RSP: 0000:ffffc90004576c28 EFLAGS: 00000283
RAX: fffffffffffffff0 RBX: ffffffff902e9278 RCX: 0000000000000000
RDX: ffffc90004576da8 RSI: ffffc90004576d58 RDI: ffffc90004576d68
RBP: dffffc0000000000 R08: ffffc90004576dc7 R09: 0000000000000000
R10: ffffc90004576db8 R11: fffff520008aedb9 R12: ffffc90004576d58
R13: ffffc90004576db8 R14: ffffc90004576d68 R15: 1ffffffff205d24f
unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x4a0 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
prep_new_page mm/page_alloc.c:1712 [inline]
get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2438
shmem_alloc_folio mm/shmem.c:1851 [inline]
shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1890
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2536
shmem_fault+0x179/0x390 mm/shmem.c:2737
__do_fault+0x135/0x390 mm/memory.c:5169
do_read_fault mm/memory.c:5590 [inline]
do_fault mm/memory.c:5724 [inline]
do_pte_missing mm/memory.c:4251 [inline]
handle_pte_fault mm/memory.c:6069 [inline]
__handle_mm_fault+0x37ed/0x5620 mm/memory.c:6212
handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6381
faultin_page mm/gup.c:1186 [inline]
__get_user_pages+0x1af4/0x30b0 mm/gup.c:1488
populate_vma_page_range+0x26b/0x340 mm/gup.c:1926
__mm_populate+0x24c/0x380 mm/gup.c:2029
mm_populate include/linux/mm.h:3348 [inline]
vm_mmap_pgoff+0x3f0/0x4c0 mm/util.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c3b18e929
RSP: 002b:00007f2c3c064038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f2c3b3b5fa0 RCX: 00007f2c3b18e929
RDX: b635773f06ebbee2 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f2c3b210b39 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2c3b3b5fa0 R15: 00007ffca556aae8
rcu: rcu_preempt kthread timer wakeup didn't happen for 10469 jiffies! g72225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=64933
rcu: rcu_preempt kthread starved for 10470 jiffies! g72225 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
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: 8896 Comm: kworker/0:0H Not tainted 6.16.0-rc4-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:__run_hrtimer kernel/time/hrtimer.c:1759 [inline]
RIP: 0010:__hrtimer_run_queues+0x4b3/0xc60 kernel/time/hrtimer.c:1825
Code: b6 6f db 0d 01 0f 85 9d 02 00 00 e8 07 ee 11 00 4d 8d 6c 24 3b 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 0f 85 4b 03 00 00 45 0f b6 6d 00 31 ff 44 89 ee e8 d6 f0 11
RSP: 0018:ffffc90000007d40 EFLAGS: 00000806
RAX: 0000000000000000 RBX: ffff8880b8627d08 RCX: dffffc0000000000
RDX: 0000000000010000 RSI: ffffffff8be1b8e0 RDI: ffffffff8be1b8a0
RBP: ffffc90000007e90 R08: ffffffff8f9fdaf7 R09: 1ffffffff1f3fb5e
R10: dffffc0000000000 R11: fffffbfff1f3fb5f R12: ffff88802852f340
R13: ffff88802852f37b R14: ffffffff897f6e00 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125c84000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 000000003667e000 CR4: 00000000003526f0
Call Trace:
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5264
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 e9 27 05 00 00 4c 8b 75 d0 4c 89 e7 e8 ff 88 d0 09 e8 5a fe 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000af0f538 EFLAGS: 00000282
RAX: df2789b8aee87e00 RBX: 0000000000000000 RCX: df2789b8aee87e00
RDX: 0000000000000006 RSI: ffffffff8d96e743 RDI: ffffffff8be1b900
RBP: ffffc9000af0f590 R08: ffffffff8f9fdaf7 R09: 1ffffffff1f3fb5e
R10: dffffc0000000000 R11: fffffbfff1f3fb5f R12: ffff888026130000
R13: dffffc0000000000 R14: ffff88807b420000 R15: ffff8880b863a9d8
context_switch kernel/sched/core.c:5399 [inline]
__schedule+0x16aa/0x4cb0 kernel/sched/core.c:6785
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965
preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
class_spinlock_irqsave_destructor include/linux/spinlock.h:585 [inline]
snd_rawmidi_transmit+0x9c/0xd0 sound/core/rawmidi.c:1493
snd_vmidi_output_work+0x1a3/0x410 sound/core/seq/seq_virmidi.c:151
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245