rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3709/1:b..l P21897/1:b..l (detected by 0, t=10504 jiffies, g=116029, q=552 ncpus=2) task:kworker/u4:6 state:R running task stack:24680 pid:21897 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6554 preempt_schedule_notrace+0xf8/0x140 kernel/sched/core.c:6816 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 rcu_is_watching+0x76/0xb0 kernel/rcu/tree.c:721 rcu_read_unlock include/linux/rcupdate.h:776 [inline] inet_twsk_purge+0xa3e/0xb60 net/ipv4/inet_timewait_sock.c:339 ops_exit_list net/core/net_namespace.c:174 [inline] cleanup_net+0x763/0xb60 net/core/net_namespace.c:601 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 task:kworker/u4:12 state:R running task stack:22272 pid:3709 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6554 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6866 irqentry_exit+0x53/0x80 kernel/entry/common.c:433 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5665 Code: 2b 00 74 08 4c 89 f7 e8 1f 6d 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000458f900 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920008b1f2c RCX: 1ffff920008b1ecc RDX: dffffc0000000000 RSI: ffffffff8aebf420 RDI: ffffffff8b3cef00 RBP: ffffc9000458fa48 R08: dffffc0000000000 R09: fffffbfff2091845 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920008b1f28 R13: dffffc0000000000 R14: ffffc9000458f960 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:306 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:755 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:826 [inline] batadv_iv_ogm_schedule+0x43b/0x1090 net/batman-adv/bat_iv_ogm.c:869 batadv_iv_send_outstanding_bat_ogm_packet+0x6fa/0x800 net/batman-adv/bat_iv_ogm.c:1713 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: rcu_preempt kthread starved for 10490 jiffies! g116029 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:25528 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6554 schedule+0xbf/0x180 kernel/sched/core.c:6630 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x2c2/0x1010 kernel/rcu/tree.c:1661 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1860 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 7680 Comm: kworker/u4:20 Not tainted 6.1.60-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline] RIP: 0010:smp_call_function_many_cond+0x1f67/0x33d0 kernel/smp.c:987 Code: e6 01 31 ff e8 6a 42 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 f5 3e 0b 00 e9 1b ff ff ff f3 90 42 0f b6 04 2b <84> c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff e8 d3 3e 0b 00 RSP: 0018:ffffc9001558f5a0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017328031 RCX: ffff88807cf43b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9001558f980 R08: ffffffff817f3f66 R09: fffffbfff2091845 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b9940188 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005646684e0968 CR3: 000000000ce8e000 CR4: 00000000003506f0 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1155 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1329 [inline] text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1529 text_poke_flush arch/x86/kernel/alternative.c:1720 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1727 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306