rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8729/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=52401, q=1011366 ncpus=2)
task:syz.0.968 state:R running task stack:26624 pid:8729 tgid:8728 ppid:5633 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7277
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7599
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x910 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x4f8/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 49 8d 1c 47 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 <48> 63 03 48 01 d8 48 8d 4b 04 48 39 e8 4c 0f 46 f9 48 8d 43 fc 4c
RSP: 0018:ffffc9000fc5f740 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff909d0884 RCX: dffffc0000000000
RDX: ffffffff909d0860 RSI: ffffffff912085ce RDI: ffffffff8c6da720
RBP: ffffffff8237a8d1 R08: 0000000000000014 R09: 0000000000000000
R10: ffffc9000fc5f838 R11: ffffffff81b28ab0 R12: ffffffff909d08ac
R13: ffffffff909d0860 R14: ffffc9000fc5f7e8 R15: ffffffff909d0860
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:183
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
__free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
__slab_free+0x274/0x2c0 mm/slub.c:5823
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5414 [inline]
__kmalloc_noprof+0x36b/0x720 mm/slub.c:5439
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc security/security.c:218 [inline]
lsm_sock_alloc security/security.c:4477 [inline]
security_sk_alloc+0x52/0x360 security/security.c:4493
sk_prot_alloc+0x101/0x210 net/core/sock.c:2255
sk_alloc+0x3a/0x390 net/core/sock.c:2308
inet6_create+0x81a/0x1270 net/ipv6/af_inet6.c:178
__sock_create+0x4b3/0x9d0 net/socket.c:1676
sock_create net/socket.c:1734 [inline]
__sys_socket_create net/socket.c:1771 [inline]
__sys_socket+0xd6/0x1b0 net/socket.c:1818
__do_sys_socket net/socket.c:1832 [inline]
__se_sys_socket net/socket.c:1830 [inline]
__x64_sys_socket+0x7a/0x90 net/socket.c:1830
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f3c39e159
RSP: 002b:00007f7f3a5f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f7f3c625fa0 RCX: 00007f7f3c39e159
RDX: 0000000000000084 RSI: 0000000000000001 RDI: 000000000000000a
RBP: 00007f7f3c43506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7f3c626038 R14: 00007f7f3c625fa0 R15: 00007f7f3c74fa48
rcu: rcu_preempt kthread starved for 787 jiffies! g52401 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7277
__schedule_loop kernel/sched/core.c:7354 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7369
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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 07/24/2026
RIP: 0010:__kasan_check_byte+0x2c/0x40 mm/kasan/common.c:578
Code: 40 d6 41 56 53 48 89 f3 49 89 fe e8 3e 15 00 00 84 c0 75 16 be 01 00 00 00 4c 89 f7 31 d2 48 89 d9 89 c3 e8 f6 04 00 00 89 d8 <5b> 41 5e e9 3c 19 b1 09 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90
RSP: 0018:ffffc90000a17770 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8177f1fc RCX: 8000000000000102
RDX: 0000000000000000 RSI: ffffffff8177f1fc RDI: 1ffffffff1dab91c
RBP: 1ffff92000142f20 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000a17918 R11: ffffffff81b28ab0 R12: ffffffff8ed5c8e0
R13: 0000000000000002 R14: ffffffff8ed5c8e0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124dce000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555595dda38 CR3: 000000007e6ce000 CR4: 00000000003526f0
Call Trace:
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire+0x7d/0x350 kernel/locking/lockdep.c:5916
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/0x2550 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
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
ref_tracker_alloc+0x15b/0x4b0 lib/ref_tracker.c:270
__netdev_tracker_alloc include/linux/netdevice.h:4528 [inline]
netdev_hold include/linux/netdevice.h:4557 [inline]
dst_init+0xbe/0x470 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:94
rt_dst_alloc net/ipv4/route.c:1681 [inline]
__mkroute_output net/ipv4/route.c:2684 [inline]
ip_route_output_key_hash_rcu+0x14ac/0x2720 net/ipv4/route.c:2904
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2734
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2961
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x762/0xfe0 net/ipv4/netfilter.c:54
synproxy_send_tcp+0x332/0x670 net/netfilter/nf_synproxy_core.c:434
synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487
nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:280 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6264 [inline]
__netif_receive_skb net/core/dev.c:6377 [inline]
process_backlog+0xa6b/0x18b0 net/core/dev.c:6728
__napi_poll+0xaa/0x330 net/core/dev.c:7787
napi_poll net/core/dev.c:7850 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8007
handle_softirqs+0x226/0x860 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: bc 88 02 c3 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 b3 c1 23 00 fb f4 8c 08 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc900001a7e40 EFLAGS: 00000242
RAX: 00000000010a40df RBX: ffffffff819bb370 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e414979 RDI: ffffffff8c6da780
RBP: ffffc900001a7f10 R08: ffff8880b8733a1b R09: 1ffff110170e6743
R10: dffffc0000000000 R11: ffffed10170e6744 R12: 0000000000000000
R13: 1ffff11003cd1bb8 R14: 1ffff92000034fd0 R15: dffffc0000000000
arch_safe_halt arch/x86/kernel/process.c:767 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:768
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x157