rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13974/1:b..l P5823/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=59365, q=2325 ncpus=2)
task:syz-executor state:R running task stack:22496 pid:5823 tgid:5823 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238
irqentry_exit+0x599/0x620 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__rcu_read_unlock+0x0/0xe0 kernel/rcu/tree_plugin.h:431
Code: d9 80 e1 07 80 c1 03 38 c1 7c dc 48 89 df e8 d7 8b 84 00 eb d2 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff
RSP: 0018:ffffc900038bf1f0 EFLAGS: 00000286
RAX: 655bbd6b6ec65200 RBX: ffffffff90b30901 RCX: 0000000000000046
RDX: 0000000000000001 RSI: ffffffff8e16c434 RDI: ffffffff8c27d500
RBP: dffffc0000000000 R08: ffffc900038bf630 R09: ffffc900038bf318
R10: dffffc0000000000 R11: fffff52000717e65 R12: ffffc900038bf640
R13: ffffc900038b8000 R14: ffffc900038bf2c8 R15: ffffffff81768a55
rcu_read_unlock include/linux/rcupdate.h:883 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x1aaf/0x23c0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 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:1433 [inline]
free_unref_folios+0xed5/0x16d0 mm/page_alloc.c:3040
folios_put_refs+0x789/0x8d0 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x240/0x9e0 mm/shmem.c:1407
evict+0x61e/0xb10 fs/inode.c:846
filename_unlinkat+0x43f/0x610 fs/namei.c:5550
__do_sys_unlink fs/namei.c:5581 [inline]
__se_sys_unlink+0x2e/0x140 fs/namei.c:5578
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb7d5d9b907
RSP: 002b:00007ffe3630ba78 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb7d5d9b907
RDX: 00007ffe3630baa0 RSI: 00007ffe3630bb30 RDI: 00007ffe3630bb30
RBP: 00007ffe3630bb30 R08: 00007ffe3630cb30 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe3630cbc0
R13: 00007fb7d5e32048 R14: 00000000000dea49 R15: 00007ffe3630cc00
task:syz.2.1957 state:R running task stack:22256 pid:13974 tgid:13974 ppid:5823 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238
irqentry_exit+0x599/0x620 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872
Code: e9 30 ff ff ff e8 85 19 0e 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 01 27 7b 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 d1 a7 6e ff cc 48 8d 3d 2e 91 73
RSP: 0018:ffffc9000213eda0 EFLAGS: 00000296
RAX: f7056bb068933600 RBX: 0000000000000246 RCX: 0000000000000046
RDX: 000000005a44979c RSI: ffffffff8e16c434 RDI: ffffffff8c27d500
RBP: 0000000000000000 R08: ffffffff81af50ad R09: ffffffff8e75e5a0
R10: dffffc0000000000 R11: ffffffff81b0dbf0 R12: 0000000000000002
R13: ffffffff8e75e5a0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
is_module_text_address+0x39/0x1e0 kernel/module/main.c:3857
kernel_text_address+0x94/0xe0 kernel/extable.c:119
__kernel_text_address+0xd/0x30 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 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:1433 [inline]
free_unref_folios+0xed5/0x16d0 mm/page_alloc.c:3040
folios_put_refs+0x789/0x8d0 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x240/0x9e0 mm/shmem.c:1407
evict+0x61e/0xb10 fs/inode.c:846
__dentry_kill+0x1a2/0x5e0 fs/dcache.c:670
finish_dput+0xc9/0x480 fs/dcache.c:879
__fput+0x691/0xa70 fs/file_table.c:477
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x23c0 kernel/exit.c:976
do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
get_signal+0x1284/0x1330 kernel/signal.c:3034
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x176/0x620 kernel/entry/common.c:219
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fb7d5d9c821
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb7d6016090 RCX: 00007fb7d5d9c819
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fb7d5e32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fb7d6016128 R14: 00007fb7d6016090 R15: 00007ffe3630c808
rcu: rcu_preempt kthread starved for 10131 jiffies! g59365 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:27696 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 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 03/18/2026
RIP: 0010:lock_acquire+0x66/0x2e0 kernel/locking/lockdep.c:5833
Code: 11 83 f8 08 0f 83 77 01 00 00 89 c0 48 0f a3 05 40 3f 70 0e 73 0d e8 c9 35 09 00 84 c0 0f 84 bc 01 00 00 83 3d 3a 72 70 0e 00 <0f> 84 c3 00 00 00 48 8b 74 24 68 4c 89 ef e8 67 4c 8e 00 83 3d 20
RSP: 0018:ffffc90000a07900 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8224c9f1 RCX: 0000000080000102
RDX: 0000000000000000 RSI: ffffffff8c27d4e0 RDI: ffffffff8c27d4a0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff81b0dbf0 R12: 0000000000000002
R13: ffffffff8e75e5a0 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125554000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002a000 CR3: 0000000059d5f000 CR4: 0000000000350ef0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_slab_page mm/slub.c:3292 [inline]
allocate_slab+0x77/0x660 mm/slub.c:3481
new_slab mm/slub.c:3539 [inline]
refill_objects+0x331/0x3c0 mm/slub.c:7175
refill_sheaf mm/slub.c:2812 [inline]
__pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615
alloc_from_pcs mm/slub.c:4717 [inline]
slab_alloc_node mm/slub.c:4851 [inline]
kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4918
__alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack_ipv6+0x16f/0xcb0 net/netfilter/nf_synproxy_core.c:874
nft_synproxy_eval_v6+0x34a/0x4e0 net/netfilter/nft_synproxy.c:91
nft_synproxy_do_eval+0x3ce/0x580 net/netfilter/nft_synproxy.c:146
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x45e/0x1990 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x29d/0x380 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6181 [inline]
__netif_receive_skb net/core/dev.c:6294 [inline]
process_backlog+0x7dd/0x1950 net/core/dev.c:6645
__napi_poll+0xae/0x340 net/core/dev.c:7709
napi_poll net/core/dev.c:7772 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7929
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
common_interrupt+0xbb/0xe0 arch/x86/kernel/irq.c:326
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 9e 6b 02 e9 8e 92 60 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 e3 b2 19 00 fb f4 67 92 60 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000246
RAX: 0000000003a5c7c9 RBX: ffffffff819a9cfa RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8defb7d5 RDI: ffffffff8c27d500
RBP: ffffc90000197f10 R08: ffff8880b873399b R09: 1ffff110170e6733
R10: dffffc0000000000 R11: ffffed10170e6734 R12: 0000000000000001
R13: 1ffff11003b58000 R14: 0000000000000001 R15: 1ffff11003b58000
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147