rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5870/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=14037, q=491514 ncpus=2)
task:syz-executor state:R running task stack:21800 pid:5870 tgid:5870 ppid:5858 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 ab 84 ad f5 cc
RSP: 0018:ffffc900040cf530 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 80acf96a2d719000
RDX: 0000000000000000 RSI: ffffffff8c036ee0 RDI: ffffffff8c036ea0
RBP: ffffffff8173bd25 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900040cf6f8 R11: ffffffff81ac3160 R12: 0000000000000002
R13: ffffffff8e33c820 R14: 0000000000000000 R15: 0000000000000000
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1169 [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
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_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906
discard_slab mm/slub.c:3252 [inline]
__put_partials+0x146/0x170 mm/slub.c:3715
put_cpu_partial+0x17c/0x250 mm/slub.c:3790
__slab_free+0x2b9/0x390 mm/slub.c:5615
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4770 [inline]
slab_alloc_node mm/slub.c:5068 [inline]
__kmalloc_cache_noprof+0x36f/0x6f0 mm/slub.c:5452
kmalloc_noprof include/linux/slab.h:956 [inline]
kzalloc_noprof include/linux/slab.h:1090 [inline]
ref_tracker_alloc+0x133/0x460 lib/ref_tracker.c:271
__netns_tracker_alloc include/net/net_namespace.h:357 [inline]
netns_tracker_alloc include/net/net_namespace.h:366 [inline]
get_net_track include/net/net_namespace.h:383 [inline]
sk_alloc+0x1b1/0x370 net/core/sock.c:2307
inet_create+0x7a0/0x1000 net/ipv4/af_inet.c:326
__sock_create+0x4b3/0x9f0 net/socket.c:1592
sock_create net/socket.c:1650 [inline]
__sys_socket_create net/socket.c:1687 [inline]
__sys_socket+0xd7/0x1b0 net/socket.c:1734
__do_sys_socket net/socket.c:1748 [inline]
__se_sys_socket net/socket.c:1746 [inline]
__x64_sys_socket+0x7a/0x90 net/socket.c:1746
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5dc9190ac7
RSP: 002b:00007fff67fea3e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5dc9190ac7
RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 00007fff67feab1c R08: 0000000000000000 R09: 00007fff67fea827
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f5dc93a4e60
R13: 0000555584c7f590 R14: 0000000000023589 R15: 00007f5dc93a7020
rcu: rcu_preempt kthread starved for 5924 jiffies! g14037 f0x2 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:27256 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7148
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7172
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
__mod_timer+0xb37/0xf30 kernel/time/timer.c:1139
schedule_timeout+0x126/0x270 kernel/time/sleep_timeout.c:98
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+0x4bc/0x870 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 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_acquire+0x175/0x360 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 0b 23 26 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000a07c58 EFLAGS: 00000206
RAX: 67cadc10e8f7da00 RBX: 0000000000000000 RCX: 67cadc10e8f7da00
RDX: 0000000000000000 RSI: ffffffff8ddae1af RDI: ffffffff8c036f00
RBP: ffffffff8173bd25 R08: 0000000000000000 R09: ffffffff8173bd25
R10: ffffc90000a07e18 R11: ffffffff81ac3160 R12: 0000000000000002
R13: ffffffff8e33c820 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff888125ae8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff0cabffffc CR3: 0000000031174000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1169 [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:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
__kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5b/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2474 [inline]
slab_free mm/slub.c:6181 [inline]
kmem_cache_free+0x19a/0x690 mm/slub.c:6292
nft_synproxy_eval_v6+0x376/0x560 net/netfilter/nft_synproxy.c:91
nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x25d/0x340 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+0x206/0x3a0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6040 [inline]
__netif_receive_skb+0xd3/0x380 net/core/dev.c:6153
process_backlog+0x60e/0x14f0 net/core/dev.c:6505
__napi_poll+0xc7/0x360 net/core/dev.c:7555
napi_poll net/core/dev.c:7618 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7745
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc 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 63 2b 25 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:ffffc90000197de0 EFLAGS: 000002c2
RAX: 67cadc10e8f7da00 RBX: ffffffff81968208 RCX: 67cadc10e8f7da00
RDX: 0000000000000001 RSI: ffffffff8dbbd648 RDI: ffffffff8c036f00
RBP: ffffc90000197f10 R08: ffff8880b8732f9b R09: 1ffff110170e65f3
R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fc3f330
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a55b58
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147