rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1136/1:b..l P8005/1:b..l P8006/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=21613, q=640 ncpus=2)
task:syz.3.533 state:R running task stack:25864 pid:8006 tgid:8004 ppid:5841 task_flags:0x40054c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
RIP: 0010:unwind_next_frame+0xc52/0x2390 arch/x86/kernel/unwind_orc.c:585
Code: 96 c0 20 c8 3c 01 0f 85 df 0c 00 00 48 89 df e8 84 23 00 00 48 89 c3 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 <4c> 8b 7c 24 18 74 08 4c 89 ff e8 1f bb b1 00 49 89 1f 48 8b 44 24
RSP: 0018:ffffc9001d8e6d78 EFLAGS: 00000246
RAX: 1ffff92003b1cdd2 RBX: ffffffff8185f4a5 RCX: 1ffff92003b1cd01
RDX: ffffffff8fea01c4 RSI: 0000000000000002 RDI: ffffc9001d8e7c88
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff81723db5
R10: dffffc0000000000 R11: ffffffff81aad930 R12: ffffc9001d8e8000
R13: 1ffff92003b1cdcb R14: ffffc9001d8e6e48 R15: ffffc9001d8e0000
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:1394 [inline]
free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963
folios_put_refs+0x584/0x670 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120
shmem_truncate_range mm/shmem.c:1232 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:966
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f31cf58d97f
RSP: 002b:00007f31d037cdf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: 0000000000dd9000 RBX: 0000000001000000 RCX: 00007f31cf58d97f
RDX: 0000000001000000 RSI: 00007f31c5200000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009756
R10: 0000200000025d82 R11: 0000000000000293 R12: 0000000000000004
R13: 00007f31d037cef0 R14: 00007f31d037ceb0 R15: 00007f31c5200000
task:syz.3.533 state:X running task stack:25320 pid:8005 tgid:8004 ppid:5841 task_flags:0x40054c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:dec_rlimit_ucounts+0x4/0x180 kernel/ucount.c:265
Code: 10 5b 41 5c 41 5d 41 5e 41 5f 5d e9 41 f2 82 ff cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 20 49 89 d6 89 f5 49 89 fc
RSP: 0018:ffffc9001e5cf918 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffff81829210 RCX: 7b5b615997dd4500
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff8dbedae0
RBP: ffffc9001e5cfad0 R08: 0000000000000000 R09: ffffffff81829210
R10: dffffc0000000000 R11: fffff52003cb9f4c R12: dffffc0000000000
R13: ffffc9001e5cfa40 R14: ffffffff8dbedae0 R15: ffff88804ffa3c80
release_task+0x38e/0x17f0 kernel/exit.c:256
exit_notify kernel/exit.c:778 [inline]
do_exit+0x15f2/0x2300 kernel/exit.c:978
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f31cf58eec9
RSP: 002b:00007f31d04030e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f31cf7e5fa8 RCX: 00007f31cf58eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f31cf7e5fa8
RBP: 00007f31cf7e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31cf7e6038 R14: 00007fff1137fa60 R15: 00007fff1137fb48
task:kworker/u8:6 state:R running task stack:23056 pid:1136 tgid:1136 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x180c/0x2390 arch/x86/kernel/unwind_orc.c:665
Code: 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 39 06 4c 8b 7c 24 48 48 8b 7c 24 70 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 <74> 05 e8 7d ae b1 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03
RSP: 0018:ffffc90003a7f2d8 EFLAGS: 00000246
RAX: 1ffff9200074fe88 RBX: ffffffff8fe86001 RCX: 0000000000000001
RDX: ffffc90003a7f448 RSI: dffffc0000000000 RDI: ffffc90003a7f440
RBP: dffffc0000000000 R08: ffffc90003a7f490 R09: ffffc90003a7f458
R10: dffffc0000000000 R11: fffff5200074fe8d R12: ffffc90003a7f490
R13: ffffc90003a7f458 R14: ffffc90003a7f408 R15: ffffffff81723db5
__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
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:262 [inline]
__kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5724
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2466 [inline]
slab_free mm/slub.c:6566 [inline]
kmem_cache_free+0x16f/0x690 mm/slub.c:6676
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2824
io_req_caches_free+0x21/0x60 io_uring/io_uring.c:2836
io_ring_exit_work+0x415/0x930 io_uring/io_uring.c:3034
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10553 jiffies! g21613 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:27256 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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+0x439/0x7d0 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: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 9e a7 d8 f5 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 93 8c 10 00 f3 0f 1e fa fb f4 73 a7 d8 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8da07d80 EFLAGS: 000002c2
RAX: 1710bfdc6071d600 RBX: ffffffff81952927 RCX: 1710bfdc6071d600
RDX: 0000000000000001 RSI: ffffffff8d513725 RDI: ffffffff8b9ee960
RBP: ffffffff8da07eb8 R08: ffff8880b8832fdb R09: 1ffff110171065fb
R10: dffffc0000000000 R11: ffffed10171065fc R12: ffffffff8f5bf730
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b52a40
FS: 0000000000000000(0000) GS:ffff88812637d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005620a6144a38 CR3: 0000000030ce6000 CR4: 0000000000350ef0
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:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3ae/0x410 init/main.c:1111
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