rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4264/1:b..l
(detected by 1, t=10503 jiffies, g=11737, q=269)
task:kworker/u4:5 state:R running task stack:24312 pid: 4264 ppid: 2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 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 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc900034df900 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00c5416a2e4a2d00
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980
RBP: ffffc900034dfa20 R08: dffffc0000000000 R09: 1ffffffff203a818
R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffffffff8c31eaa0
R13: 1ffff9200069bf2c R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
inet_twsk_purge+0x119/0x840 net/ipv4/inet_timewait_sock.c:268
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x791/0xba0 net/core/net_namespace.c:635
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10532 jiffies! g11737 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27416 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5082 Comm: syz.1.25 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:asm_sysvec_apic_timer_interrupt+0x0/0x20 arch/x86/include/asm/idtentry.h:675
Code: e9 e5 04 00 00 90 90 90 90 90 0f 01 ca fc 6a ff e8 e5 03 00 00 48 89 c4 48 89 e7 e8 ca 56 dc ff e9 c5 04 00 00 90 90 90 90 90 <0f> 01 ca fc 6a ff e8 c5 03 00 00 48 89 c4 48 89 e7 e8 1a 55 dc ff
RSP: 0018:ffffc900033ffaf8 EFLAGS: 00040002
RAX: ffffffff812c4714 RBX: 00007f99187e2d00 RCX: ffff888019be1dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900033ffcb0 R08: ffff888019be1dc7 R09: 1ffff1100337c3b8
R10: dffffc0000000000 R11: ffffed100337c3b9 R12: 0000000000000007
R13: 00000000ffffffff R14: 1ffff9200067ff74 R15: 0000000000000000
FS: 00007f99187e36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000074ba7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
RIP: 0010:xsave_to_user_sigframe arch/x86/include/asm/fpu/internal.h:351 [inline]
RIP: 0010:copy_fpregs_to_sigframe arch/x86/kernel/fpu/signal.c:141 [inline]
RIP: 0010:copy_fpstate_to_sigframe+0x48e/0xbf0 arch/x86/kernel/fpu/signal.c:203
Code: 49 89 c7 48 89 c6 41 bd ff ff ff ff 4c 21 ee 31 ff e8 e6 dd 4c 00 4d 21 ef 75 41 e8 fc d9 4c 00 41 81 e4 ff 02 00 00 0f 01 cb <48> 89 df 44 89 e0 31 d2 48 0f ae 27 31 c0 41 89 c4 0f 01 ca 4c 8b
RSP: 0018:ffffc900033ffb20 EFLAGS: 00040202
get_sigframe arch/x86/kernel/signal.c:295 [inline]
__setup_rt_frame arch/x86/kernel/signal.c:471 [inline]
setup_rt_frame arch/x86/kernel/signal.c:780 [inline]
handle_signal arch/x86/kernel/signal.c:824 [inline]
arch_do_signal_or_restart+0x679/0x12c0 arch/x86/kernel/signal.c:869
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f991917fef7
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f99187e30e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f99193eafa8 RCX: 00007f991917fef9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f99193eafa8
RBP: 00007f99193eafa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f99193eb038 R14: 00007ffe1c34c690 R15: 00007ffe1c34c778