rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P46/1:b..l
(detected by 0, t=10503 jiffies, g=17605, q=458 ncpus=2)
task:kworker/u4:3 state:R running task stack:23120 pid:46 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90000b779a0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 055ead03b0752600
RDX: 0000000000000000 RSI: ffffffff8a6c1180 RDI: ffffffff8abf1260
RBP: ffffc90000b77aa8 R08: dffffc0000000000 R09: fffffbfff2117049
R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: 0000000000000000
R13: 1ffff9200016ef40 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
cond_resched_rcu+0xd4/0x160 include/linux/sched.h:2152
ip_vs_conn_flush net/netfilter/ipvs/ip_vs_conn.c:1393 [inline]
ip_vs_conn_net_cleanup+0x393/0x560 net/netfilter/ipvs/ip_vs_conn.c:1475
__ip_vs_cleanup_batch+0x6f/0xf0 net/netfilter/ipvs/ip_vs_core.c:2353
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x77b/0xb80 net/core/net_namespace.c:640
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: rcu_preempt kthread starved for 10528 jiffies! g17605 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:26912 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5120 Comm: syz.4.20 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lockdep_hardirqs_on+0x2/0x140 kernel/locking/lockdep.c:4321
Code: ca 6a 8a e8 90 9d f4 ff 80 3d 52 f3 da 03 00 74 01 c3 c6 05 48 f3 da 03 01 48 c7 c7 80 f7 6b 8a e8 c3 b6 3d f7 0f 0b c3 41 56 <53> 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 48 8b
RSP: 0018:ffffc900037a7a90 EFLAGS: 00000046
RAX: 5e1c40ec63306800 RBX: 0000000000000200 RCX: 5e1c40ec63306800
RDX: dffffc0000000000 RSI: ffffffff8a6c1180 RDI: ffffffff814e5e9a
RBP: ffffc900037a7b30 R08: dffffc0000000000 R09: ffffed10052f0001
R10: ffffed10052f0001 R11: 1ffff110052f0000 R12: ffffffff812f3bd4
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920006f4f54
FS: 00007ffb83e136c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000005be2a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__local_bh_enable_ip+0x12a/0x1b0 kernel/softirq.c:408
local_bh_enable include/linux/bottom_half.h:33 [inline]
fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline]
restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:331 [inline]
__fpu_restore_sig arch/x86/kernel/fpu/signal.c:359 [inline]
fpu__restore_sig+0x9a1/0x1190 arch/x86/kernel/fpu/signal.c:493
restore_sigcontext arch/x86/kernel/signal.c:140 [inline]
__ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:675
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ffb82f8e967
Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89
RSP: 002b:00007ffb83e130e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007ffb831b5fa8 RCX: 00007ffb82f8e969
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ffb831b5fa8
RBP: 00007ffb831b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffb831b5fac
R13: 0000000000000000 R14: 00007ffd52a7a370 R15: 00007ffd52a7a458
sched: RT throttling activated