rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5198/1:b..l P6982/1:b..l P13267/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=68153, q=771 ncpus=2)
task:sed state:R running task stack:24312 pid:13267 tgid:13267 ppid:13266 task_flags:0x40000c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x20/0x3b0 kernel/locking/lockdep.c:5876
Code: 90 90 90 90 90 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 00 02 e0 10 <48> 89 44 24 28 0f 1f 44 00 00 65 8b 05 03 02 e0 10 83 f8 08 0f 83
RSP: 0018:ffffc90003dcf150 EFLAGS: 00000286
RAX: 3dc4f0d79390ab00 RBX: ffffffff90236d01 RCX: 3dc4f0d79390ab00
RDX: ffffc90003dcf201 RSI: ffffffff81743f85 RDI: ffffffff8df41a60
RBP: dffffc0000000000 R08: ffffc90003dcf530 R09: 0000000000000000
R10: ffffc90003dcf2d8 R11: fffff520007b9e5d R12: ffffc90003dcf540
R13: ffffffff81743f85 R14: ffffffff8df41a60 R15: ffffffff81743f85
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
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:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:3000
folios_put_refs+0x584/0x670 mm/swap.c:1002
free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:355
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a2/0x680 mm/mmu_gather.c:404
tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:503
exit_mmap+0x439/0xb10 mm/mmap.c:1290
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb30a226c5
RSP: 002b:00007ffca376edc8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fdb30b23fe8 RCX: 00007fdb30a226c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdb30b22680 R15: 00007fdb30b24000
task:kworker/u8:22 state:R running task stack:21144 pid:6982 tgid:6982 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x16c/0x340 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 94 31 e0 10 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000c01f018 EFLAGS: 00000206
RAX: ff1ea7ca16577f00 RBX: 0000000000000000 RCX: ff1ea7ca16577f00
RDX: 00000000caa8f0e8 RSI: ffffffff8d97863f RDI: ffffffff8bc07b60
RBP: ffffffff81743f85 R08: ffffffff81743f85 R09: ffffffff8df41a60
R10: ffffc9000c01f1d8 R11: ffffffff81ada810 R12: 0000000000000002
R13: ffffffff8df41a60 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [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
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
kmem_alloc_batch lib/debugobjects.c:371 [inline]
fill_pool+0x100/0x570 lib/debugobjects.c:403
debug_objects_fill_pool lib/debugobjects.c:725 [inline]
debug_object_activate+0x498/0x540 lib/debugobjects.c:814
debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
__call_rcu_common kernel/rcu/tree.c:3104 [inline]
call_rcu+0xaa/0x9c0 kernel/rcu/tree.c:3239
slab_free_hook mm/slub.c:2504 [inline]
slab_free mm/slub.c:6668 [inline]
kmem_cache_free+0x488/0x620 mm/slub.c:6779
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2823
io_req_caches_free+0x21/0x60 io_uring/io_uring.c:2835
io_ring_exit_work+0x3b3/0x8d0 io_uring/io_uring.c:3021
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:udevd state:R running task stack:22712 pid:5198 tgid:5198 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x0/0x3b0 kernel/locking/lockdep.c:5876
Code: 41 be 00 00 50 00 e9 70 fe ff ff 41 be 2f 00 00 00 e9 0e ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49
RSP: 0018:ffffc90003017798 EFLAGS: 00000293
RAX: ffffffff826454e7 RBX: ffffffff826453ac RCX: ffff88807d341e80
RDX: 0000000000000000 RSI: ffffffff826453ac RDI: ffffffff8df41a60
RBP: 0000000000000001 R08: ffffffff826453ac R09: ffffffff8df41a60
R10: dffffc0000000000 R11: ffffed10283f24d3 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff88801cab0000 R15: ffff88801df52d20
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
kernfs_root+0x1e5/0x230 fs/kernfs/kernfs-internal.h:80
kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline]
kernfs_rcu_name fs/kernfs/kernfs-internal.h:119 [inline]
kernfs_dop_revalidate+0x365/0x5d0 fs/kernfs/dir.c:1195
d_revalidate fs/namei.c:969 [inline]
lookup_fast+0x253/0x5b0 fs/namei.c:-1
walk_component fs/namei.c:2217 [inline]
link_path_walk+0x720/0x18d0 fs/namei.c:2589
path_lookupat+0xe4/0x8c0 fs/namei.c:2745
filename_lookup+0x212/0x570 fs/namei.c:2775
vfs_statx+0xf8/0x550 fs/stat.c:353
vfs_fstatat+0x118/0x170 fs/stat.c:375
__do_sys_newfstatat fs/stat.c:542 [inline]
__se_sys_newfstatat fs/stat.c:536 [inline]
__x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc519111b0a
RSP: 002b:00007ffedd47f118 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffedd47f5b0 RCX: 00007fc519111b0a
RDX: 00007ffedd47f120 RSI: 00007ffedd47f5b0 RDI: 00000000ffffff9c
RBP: 000055b449220910 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffedd47f1b0
R13: 0000000000000100 R14: 000055b411ec5be0 R15: 00007ffedd47fc30
rcu: rcu_preempt kthread starved for 10619 jiffies! g68153 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27200 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 13 ee 02 00 cc cc cc 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 73 e0 0c 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: cd760d0bf6c21a00 RBX: ffffffff8197971a RCX: cd760d0bf6c21a00
RDX: 0000000000000001 RSI: ffffffff8d791c56 RDI: ffffffff8bc07b60
RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f820870
R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f118982ea10 CR3: 0000000067c48000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3a7/0x400 init/main.c:1206
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147