rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20861/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=185345, q=2049 ncpus=2)
task:syz-executor state:S stack:21512 pid:20861 tgid:20861 ppid:20837 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6966
preempt_schedule+0xae/0xc0 kernel/sched/core.c:6990
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
d_walk+0x3d0/0x780 fs/dcache.c:1354
shrink_dcache_parent+0xed/0x2c0 fs/dcache.c:1553
d_invalidate+0x11b/0x260 fs/dcache.c:1658
proc_invalidate_siblings_dcache+0x3d3/0x6c0 fs/proc/inode.c:142
release_task+0x1306/0x17f0 kernel/exit.c:292
wait_task_zombie kernel/exit.c:1267 [inline]
wait_consider_task+0x195a/0x2e60 kernel/exit.c:1494
do_wait_thread kernel/exit.c:1557 [inline]
__do_wait+0x153/0x740 kernel/exit.c:1675
do_wait+0x1f8/0x520 kernel/exit.c:1709
kernel_wait4+0x1af/0x280 kernel/exit.c:1868
__do_sys_wait4 kernel/exit.c:1896 [inline]
__se_sys_wait4 kernel/exit.c:1892 [inline]
__x64_sys_wait4+0x133/0x1e0 kernel/exit.c:1892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7eff03b84e57
RSP: 002b:00007fffab91ca00 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000000000000066a RCX: 00007eff03b84e57
RDX: 0000000040000000 RSI: 00007fffab91ca6c RDI: 00000000ffffffff
RBP: 00007fffab91ca6c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000001fa
R13: 0000555592129590 R14: 00000000002f14f4 R15: 00007fffab91cac0
rcu: rcu_preempt kthread starved for 300 jiffies! g185345 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:26464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lockdep_rtnl_is_held+0x0/0x40 net/core/rtnetlink.c:181
Code: 89 fb e8 73 e6 6b f8 48 89 df 48 c7 c6 a0 9e 50 8f 5b e9 83 15 65 fb 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 53 e8 46 e6 6b f8 48 c7 c7 08 9f 50 8f be ff ff ff ff
RSP: 0018:ffffc90000a078b8 EFLAGS: 00000202
RAX: ffffffff8a1e29c6 RBX: ffff88807bf13000 RCX: 0000000000000100
RDX: ffff88801d2b5a00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 1ffff1100af44199 R08: ffffc90000a07bc0 R09: ffffc90000a07bd0
R10: ffffc90000a07a20 R11: fffff52000140f46 R12: 0000000000000001
R13: 0000000000000003 R14: 1ffff1100af4419b R15: ffff888057a20cdf
FS: 0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fddaaa00000 CR3: 000000006d22e000 CR4: 00000000003526f0
Call Trace:
__in6_dev_get include/net/addrconf.h:347 [inline]
ip6_ignore_linkdown include/net/addrconf.h:443 [inline]
find_match+0xd0/0xc90 net/ipv6/route.c:781
__find_rr_leaf+0x23a/0x6d0 net/ipv6/route.c:869
find_rr_leaf net/ipv6/route.c:890 [inline]
rt6_select net/ipv6/route.c:934 [inline]
fib6_table_lookup+0x39f/0xa80 net/ipv6/route.c:2232
ip6_pol_route+0x222/0x1180 net/ipv6/route.c:2268
pol_lookup_func include/net/ip6_fib.h:617 [inline]
fib6_rule_lookup+0x1fc/0x6f0 net/ipv6/fib6_rules.c:120
ip6_route_output_flags_noref net/ipv6/route.c:2683 [inline]
ip6_route_output_flags+0x364/0x5d0 net/ipv6/route.c:2695
ip6_route_output include/net/ip6_route.h:93 [inline]
__nf_ip6_route+0x42/0xd0 net/ipv6/netfilter.c:113
nf_ip6_route include/linux/netfilter_ipv6.h:111 [inline]
synproxy_send_tcp_ipv6+0x24a/0x680 net/netfilter/nf_synproxy_core.c:835
synproxy_send_client_synack_ipv6+0x80e/0xca0 net/netfilter/nf_synproxy_core.c:897
nft_synproxy_eval_v6+0x36e/0x560 net/netfilter/nft_synproxy.c:90
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+0x409/0x1920 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:157 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:272 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:491
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317
__netif_receive_skb_one_core net/core/dev.c:5977 [inline]
__netif_receive_skb+0xd3/0x380 net/core/dev.c:6090
process_backlog+0x60e/0x14f0 net/core/dev.c:6442
__napi_poll+0xc4/0x480 net/core/dev.c:7414
napi_poll net/core/dev.c:7478 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7605
handle_softirqs+0x283/0x870 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:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 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+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 de 02 00 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 d3 ad 21 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: 9ad5875d205d0100 RBX: ffffffff81976918 RCX: 9ad5875d205d0100
RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fa0b3f0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a56b40
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:749
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147