rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5216/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=15037, q=1159464 ncpus=2)
task:udevd state:R running task stack:24904 pid:5216 tgid:5216 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:stack_access_ok+0x1d/0x200 arch/x86/kernel/unwind_orc.c:393
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 4c 8d 77 08 41 55 41 54 49 89 d4 4c 89 f2 55 <48> c1 ea 03 48 89 f5 53 48 89 fb 48 83 ec 08 80 3c 02 00 0f 85 94
RSP: 0018:ffffc9000fd3f400 EFLAGS: 00000283
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff913f7ede
RDX: ffffc9000fd3f4f8 RSI: ffffc9000fd3f580 RDI: ffffc9000fd3f4f0
RBP: ffffc9000fd3f580 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 00000000000061ed R12: 0000000000000008
R13: ffffc9000fd3f4f0 R14: ffffc9000fd3f4f8 R15: ffffc9000fd3f524
deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
unwind_next_frame+0x15c5/0x20a0 arch/x86/kernel/unwind_orc.c:648
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4281
kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:578
__alloc_skb+0x166/0x380 net/core/skbuff.c:669
alloc_skb include/linux/skbuff.h:1336 [inline]
netlink_alloc_large_skb+0x69/0x130 net/netlink/af_netlink.c:1186
netlink_sendmsg+0x6a1/0xdd0 net/netlink/af_netlink.c:1871
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
__sys_sendmsg+0x16d/0x220 net/socket.c:2700
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b8b8a7407
RSP: 002b:00007fffb7fb2c60 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4b8bf68880 RCX: 00007f4b8b8a7407
RDX: 0000000000000000 RSI: 00007fffb7fb2cc0 RDI: 0000000000000004
RBP: 000055ac6e281620 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000093
R13: 000055ac6e033d80 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 9283 jiffies! g15037 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:27368 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
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 6.16.0-syzkaller-12063-g37816488247d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: f7 3d 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 62 37 13 0f 0f 82 74 02 00 00 8b 35 2a 69 13 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 b9 f6 3d 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc90000a07da0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e5c1160 RCX: 000000007f1fed10
RDX: 0000000000000000 RSI: ffffffff8de29498 RDI: ffffffff8c161180
RBP: 0000000000000002 R08: 03813abc02fcf7df R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881247c4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f74308e6865 CR3: 0000000078839000 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:1155 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
ref_tracker_alloc+0x1d2/0x5b0 lib/ref_tracker.c:277
__netdev_tracker_alloc include/linux/netdevice.h:4346 [inline]
netdev_hold include/linux/netdevice.h:4375 [inline]
dst_init+0xda/0x580 net/core/dst.c:52
dst_alloc+0xbb/0x1a0 net/core/dst.c:93
rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1645
__mkroute_output net/ipv4/route.c:2645 [inline]
ip_route_output_key_hash_rcu+0x880/0x28c0 net/ipv4/route.c:2866
ip_route_output_key_hash+0x137/0x2e0 net/ipv4/route.c:2696
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2923
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x55d/0x12e0 net/ipv4/netfilter.c:53
synproxy_send_tcp.isra.0+0x2fa/0x630 net/netfilter/nf_synproxy_core.c:431
synproxy_send_client_synack+0x6f6/0x8f0 net/netfilter/nf_synproxy_core.c:484
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e6/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:260
dst_input include/net/dst.h:471 [inline]
ip_rcv_finish net/ipv4/ip_input.c:454 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:574
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5979
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6092
process_backlog+0x442/0x15e0 net/core/dev.c:6444
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7489
napi_poll net/core/dev.c:7552 [inline]
net_rx_action+0xa9f/0xfe0 net/core/dev.c:7679
handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 2c 63 02 c3 cc cc cc cc 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 f3 52 17 00 fb f4 4c 0d 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2
RAX: 0000000000e09935 RBX: 0000000000000001 RCX: ffffffff8b92bc29
RDX: 0000000000000000 RSI: ffffffff8de4e889 RDI: ffffffff8c161180
RBP: ffffed1003c56488 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e2b2440 R14: ffffffff90ab0090 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148