rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (2 ticks this GP) idle=d6f4/1/0x4000000000000000 softirq=50317/50317 fqs=3
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9859/3:b..l P9675/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=58121, q=2632 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9860 Comm: syz.0.1315 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:preempt_count_add+0x32/0x190 kernel/sched/core.c:5977
Code: 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 80 75 78 9a 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 ea 00 00 00 83 3d be 06 e4 18 00 <75> 07 65 8b 05 65 b1 d8 11 65 01 3d 5e b1 d8 11 48 c7 c0 80 75 78
RSP: 0018:ffffc90000007da8 EFLAGS: 00000046
RAX: 0000000000000004 RBX: ffff8880b86281c0 RCX: ffffffff9a787503
RDX: 0000000000010000 RSI: ffffffff8c4bdc60 RDI: 0000000000000001
RBP: ffff8880772b3300 R08: ffffffff90579137 R09: 1ffffffff20af226
R10: dffffc0000000000 R11: fffffbfff20af227 R12: ffff8880b86281c0
R13: 0000000000000001 R14: ffff8880b8628360 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888124f4e000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000003041dff8 CR3: 000000000e946000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:141 [inline]
_raw_spin_lock_irq+0x21/0x50 kernel/locking/spinlock.c:174
__run_hrtimer kernel/time/hrtimer.c:2036 [inline]
__hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x10/0xb0 kernel/rcu/tree.c:752
Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 10 42 c1 11 db 33 25 0a 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df
RSP: 0018:ffffc90005be6f78 EFLAGS: 00000283
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8eb59c60
RBP: ffffffff823e892e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000010 R11: ffffffff81b1fa10 R12: 0000000000000002
R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000000
trace_lock_acquire include/trace/events/lock.h:23 [inline]
lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
__update_page_owner_free_handle+0x4b/0x4a0 mm/page_owner.c:283
__reset_page_owner+0x85/0x1f0 mm/page_owner.c:321
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
free_unref_folios+0xd84/0x14a0 mm/page_alloc.c:3011
folios_put_refs+0x9e9/0xb30 mm/swap.c:1057
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1159
shmem_truncate_range mm/shmem.c:1287 [inline]
shmem_evict_inode+0x280/0xa80 mm/shmem.c:1417
evict+0x624/0xb50 fs/inode.c:825
dentry_kill+0x1b9/0x880 fs/dcache.c:826
finish_dput+0x1a/0x260 fs/dcache.c:1001
__fput+0x675/0xa50 fs/file_table.c:520
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1009
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
get_signal+0x121b/0x12c0 kernel/signal.c:3046
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
__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:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
__do_fast_syscall_32+0x45b/0x6f0 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf702f0ec
Code: Unable to access opcode bytes at 0xf702f0c2.
RSP: 002b:00000000f53fc50c EFLAGS: 00000206 ORIG_RAX: 00000000000000db
RAX: 0000000000000000 RBX: 0000000080000000 RCX: 0000000000600000
RDX: 0000000000000019 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
task:kworker/u8:35 state:R running task stack:23896 pid:9675 tgid:9675 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:100 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x515/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: 00 00 fc ff df 0f b6 04 08 84 c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 48 39 e8 4c 0f 46 f9 48 8d 43 fc 4c 0f 47 e0 4c 0f 46 eb <4d> 39 e7 76 a9 e9 7c fd ff ff 89 d9 80 e1 07 80 c1 03 38 c1 7c cd
RSP: 0000:ffffc900053af460 EFLAGS: 00000216
RAX: ffffffff907a5244 RBX: ffffffff907a5248 RCX: ffffffff907a524c
RDX: ffffffff907a522c RSI: ffffffff90fcee04 RDI: ffffffff8c4bdc20
RBP: ffffffff8234933c R08: 000000000000000f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: ffffffff907a5244
R13: ffffffff907a522c R14: ffffc900053af508 R15: ffffffff907a522c
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2638 [inline]
slab_free mm/slub.c:6377 [inline]
kmem_cache_free+0x44f/0x650 mm/slub.c:6504
__io_req_caches_free+0x1be/0x270 io_uring/io_uring.c:2148
io_req_caches_free+0x21/0x30 io_uring/io_uring.c:2160
io_ring_exit_work+0x43e/0x9a0 io_uring/io_uring.c:2363
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:syz.3.1319 state:R running task stack:25736 pid:9859 tgid:9858 ppid:5649 task_flags:0x400040 flags:0x08080001
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
filemap_map_pages+0x1a69/0x2090 mm/filemap.c:3981
do_fault_around mm/memory.c:5818 [inline]
do_read_fault mm/memory.c:5851 [inline]
do_fault mm/memory.c:5994 [inline]
do_pte_missing+0x20ae/0x34b0 mm/memory.c:4566
handle_pte_fault mm/memory.c:6379 [inline]
__handle_mm_fault mm/memory.c:6517 [inline]
handle_mm_fault+0x1b36/0x3080 mm/memory.c:6686
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x1678/0x2720 mm/gup.c:1428
populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
__mm_populate+0x25f/0x390 mm/gup.c:1963
mm_populate include/linux/mm.h:4171 [inline]
vm_mmap_pgoff+0x353/0x4e0 mm/util.c:586
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x23e/0x6f0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f260ec
RSP: 002b:00000000f53e650c EFLAGS: 00000206 ORIG_RAX: 00000000000000c0
RAX: ffffffffffffffda RBX: 0000000080000000 RCX: 0000000000b36000
RDX: 000000000200000b RSI: 0000000000008031 RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 6562 jiffies! g58121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 9846 Comm: syz.8.1314 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x11eb/0x15f0 kernel/smp.c:912
Code: 1e 89 de 83 e6 01 31 ff e8 e2 22 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1e 0c 00 eb 37 f3 90 41 0f b6 04 1c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 73 1e 0c 00 eb e5 44 89
RSP: 0000:ffffc90005ba7400 EFLAGS: 00000293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff88802ee85d00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005ba7548 R08: ffffffff90579137 R09: 1ffffffff20af226
R10: dffffc0000000000 R11: fffffbfff20af227 R12: 1ffff110170c85fd
R13: ffff8880b873c448 R14: ffff8880b8642fe8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812504e000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000565453b50a38 CR3: 000000000e946000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000004ff
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1077
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x5c4/0x1090 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423
tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:549
free_ldt_pgtables+0x192/0x360 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:229 [inline]
exit_mmap+0x1bf/0x9f0 mm/mmap.c:1285
__mmput+0x118/0x420 kernel/fork.c:1187
exit_mm+0x221/0x2d0 kernel/exit.c:615
do_exit+0x6cd/0x2360 kernel/exit.c:997
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
get_signal+0x121b/0x12c0 kernel/signal.c:3046
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
__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:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
__do_fast_syscall_32+0x45b/0x6f0 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf702f0ec
Code: Unable to access opcode bytes at 0xf702f0c2.
RSP: 002b:00000000f541d50c EFLAGS: 00000206 ORIG_RAX: 0000000000000159
RAX: 0000000000000300 RBX: 0000000000000003 RCX: 0000000080004d00
RDX: 0000000000000300 RSI: 0000000000000f00 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000