INFO: rcu detected stall in cleanup

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	INFO: rcu detected stall in cleanup_net (8) prio:normal kernfs net	1	syz, C	error		33	31d	197d	0/29	upstream: reported C repro on 2026/01/13 16:49
upstream	INFO: rcu detected stall in cleanup_net (3) net	1				1	2508d	2508d	0/29	auto-closed as invalid on 2019/12/15 02:54
upstream	INFO: rcu detected stall in cleanup_net (6) net	1				63	1055d	1298d	0/29	closed as invalid on 2023/10/27 14:39
linux-4.19	INFO: rcu detected stall in cleanup_net (2)	1				4	1858d	1990d	0/1	auto-closed as invalid on 2021/10/25 03:43
upstream	INFO: rcu detected stall in cleanup_net kernel	1				5	2940d	3008d	0/29	closed as invalid on 2018/09/05 12:51
upstream	INFO: rcu detected stall in cleanup_net (4) kernel	1	syz, C	done		5	2153d	2149d	15/29	fixed on 2020/10/10 01:52
upstream	INFO: rcu detected stall in cleanup_net (5) net	1				24	1636d	1896d	0/29	closed as invalid on 2022/02/08 10:00
linux-6.1	INFO: rcu detected stall in cleanup_net origin:lts-only	1	syz		inconclusive	143	158d	1113d	0/3	upstream: reported syz repro on 2023/07/12 14:45
upstream	INFO: rcu detected stall in cleanup_net (2) kernel	1				1	2851d	2847d	0/29	auto-closed as invalid on 2019/04/05 22:14
upstream	INFO: rcu detected stall in cleanup_net (7) kernfs rdma bridge	1				15	609d	986d	0/29	auto-obsoleted due to no activity on 2025/02/25 20:50
linux-5.15	INFO: rcu detected stall in cleanup_net origin:lts-only	1	syz, C		inconclusive	190	9d07h	1114d	0/3	upstream: reported C repro on 2023/07/11 05:04

batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=456/1/0x4000000000000002 softirq=517147/517148 fqs=9 rcu: (t=10502 jiffies g=529301 q=1034) rcu: rcu_preempt kthread starved for 10485 jiffies! g529301 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29104 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x4db/0xfc0 kernel/time/timer.c:1806 rcu_gp_kthread+0xd5c/0x2190 kernel/rcu/tree.c:2202 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 NMI backtrace for cpu 0 CPU: 0 PID: 3263 Comm: kworker/u4:4 Not tainted 4.19.97-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x189/0x1d5 kernel/rcu/tree.c:1340 print_cpu_stall kernel/rcu/tree.c:1478 [inline] check_cpu_stall kernel/rcu/tree.c:1550 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0x5e3/0xd90 kernel/rcu/tree.c:2682 update_process_times+0x32/0x80 kernel/time/timer.c:1638 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:164 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x33b/0xdc0 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x111/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 </IRQ> RIP: 0010:should_resched arch/x86/include/asm/preempt.h:99 [inline] RIP: 0010:__local_bh_enable_ip+0x18e/0x270 kernel/softirq.c:196 Code: 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 df 00 00 00 48 83 3d a7 27 b2 07 00 0f 84 8f 00 00 00 fb 66 0f 1f 44 00 00 <65> 8b 05 8b b9 c1 7e 85 c0 74 7f 5b 41 5c 41 5d 5d c3 80 3d 07 53 RSP: 0018:ffff88805cb8f898 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11e4b7b RBX: 0000000000000201 RCX: 1ffff11002913d60 RDX: dffffc0000000000 RSI: ffff88801489eae0 RDI: ffff88801489ea3c RBP: ffff88805cb8f8b0 R08: ffff88801489e1c0 R09: ffff88801489eb00 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff873c093a R13: ffff88801489e1c0 R14: ffff88804c8499c0 R15: dffffc0000000000 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x31/0x40 kernel/locking/spinlock.c:200 spin_unlock_bh include/linux/spinlock.h:374 [inline] batadv_tt_local_purge+0x27a/0x360 net/batman-adv/translation-table.c:1454 batadv_tt_local_resize_to_mtu+0x98/0x140 net/batman-adv/translation-table.c:4205 batadv_update_min_mtu net/batman-adv/hard-interface.c:637 [inline] batadv_hardif_deactivate_interface.part.0+0xfb/0x102 net/batman-adv/hard-interface.c:686 batadv_hardif_deactivate_interface net/batman-adv/hard-interface.c:445 [inline] batadv_hardif_disable_interface.cold+0x4d7/0xbe9 net/batman-adv/hard-interface.c:853 batadv_softif_destroy_netlink+0xad/0x150 net/batman-adv/soft-interface.c:1151 default_device_exit_batch+0x25c/0x410 net/core/dev.c:9778 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:156 cleanup_net+0x404/0x960 net/core/net_namespace.c:553 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 net_ratelimit: 3868 callbacks suppressed batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) net_ratelimit: 4424 callbacks suppressed batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (20160)