rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P38/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=22889, q=3902 ncpus=2)
task:khugepaged state:R running task stack:28008 pid:38 tgid:38 ppid:2 task_flags:0x200040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:copy_mc_enhanced_fast_string+0x6/0xf arch/x86/lib/copy_mc_64.S:130
Code: 89 ca e9 1d fe ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 89 f8 48 89 d1 a4 31 c0 c3 cc cc cc cc 48 89 c8 c3 cc cc cc cc 66 0f 1f 84 00
RSP: 0018:ffffc90000ae7850 EFLAGS: 00010246
RAX: ffff8880425c6000 RBX: 0000000000001000 RCX: 0000000000000680
RDX: 0000000000001000 RSI: ffff88807d8c3980 RDI: ffff8880425c6980
RBP: ffff8880425c6000 R08: 0000000000000000 R09: ffffed100fb187ff
R10: ffff88807d8c3fff R11: 0000000000000000 R12: ffff88807d8c3000
R13: ffffc90000ae79d0 R14: 00000000000001c6 R15: 00000000000140ed
copy_mc_to_kernel+0x47/0xc0 arch/x86/lib/copy_mc.c:75
copy_mc_user_highpage include/linux/highmem.h:441 [inline]
__collapse_huge_page_copy mm/khugepaged.c:813 [inline]
collapse_huge_page+0x23af/0x3840 mm/khugepaged.c:1218
collapse_scan_pmd mm/khugepaged.c:1425 [inline]
collapse_single_pmd+0x2a9a/0x3c50 mm/khugepaged.c:2437
collapse_scan_mm_slot mm/khugepaged.c:2552 [inline]
khugepaged_do_scan mm/khugepaged.c:2632 [inline]
khugepaged+0x10fd/0x14f0 mm/khugepaged.c:2687
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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 1322 jiffies! g22889 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:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:check_preemption_disabled+0x23/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 65 88 80 08 65 f7 05 56 88 80 08 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b <5d> 41 5c c3 cc cc cc cc 9c 58 f6 c4 02 74 ea 65 4c 8b 25 1e 88 80
RSP: 0018:ffffc90000a07f68 EFLAGS: 00000296
RAX: 0000000000000001 RBX: ffffffff8e7e54e0 RCX: ffffffff9207f101
RDX: 0000000000000000 RSI: ffffffff8c1c3600 RDI: ffffffff8c1c3640
RBP: ffffffff81b7c1ae R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000008636b R12: ffffc90000a080a0
R13: ffffc90000a08050 R14: ffffc90000a08f20 R15: ffffc90000a08084
FS: 0000000000000000(0000) GS:ffff888124475000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c3089d5960 CR3: 000000005d993000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x245/0x310 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_node_noprof+0x25a/0x6f0 mm/slub.c:4950
kmalloc_reserve+0x148/0x350 net/core/skbuff.c:613
__alloc_skb+0x185/0x710 net/core/skbuff.c:713
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack+0x19e/0x970 net/netfilter/nf_synproxy_core.c:461
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:60 [inline]
nft_synproxy_do_eval+0xa6a/0xd50 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e5/0x1950 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262
dst_input include/net/dst.h:480 [inline]
ip_rcv_finish net/ipv4/ip_input.c:492 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:612
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6202
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6315
process_backlog+0x37a/0x1580 net/core/dev.c:6666
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7730
napi_poll net/core/dev.c:7793 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7950
handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 36 93 02 e9 c3 42 03 00 0f 1f 00 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 70 21 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000242
RAX: 0000000001835a75 RBX: ffff88801e2ba500 RCX: ffffffff8b8a2045
RDX: 0000000000000000 RSI: ffffffff8df1ff3e RDI: ffffffff8c1c3680
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67b5
R10: ffff8880b8533dab R11: 0000000000000000 R12: 0000000000000001
R13: ffffed1003c574a0 R14: 0000000000000001 R15: ffffffff90d79c50
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148