rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=14533, q=776 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294974785-4294964285), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14533 f0x2 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:28320 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0xee1/0x59f0 kernel/sched/core.c:6710 schedule+0xe7/0x1b0 kernel/sched/core.c:6786 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1808 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.5.0-rc5-syzkaller-00192-g829c6524d672 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:write_comp_data+0x7/0x90 kernel/kcov.c:230 Code: 81 e2 00 01 ff 00 75 10 65 48 8b 04 25 80 b9 03 00 48 8b 80 f8 15 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 65 8b 05 c1 b6 7d 7e <49> 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 RSP: 0018:ffffc90000007bb8 EFLAGS: 00000246 RAX: 0000000000000101 RBX: ffffc900138777d0 RCX: ffffffff885831ba RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff88802aebeb00 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000004e R12: ffffc90013877808 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 000000007c8df000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pie_calculate_probability+0x64a/0x850 net/sched/sch_pie.c:410 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x764/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5729 Code: c1 05 d5 6e 9b 7e 83 f8 01 0f 85 b0 02 00 00 9c 58 f6 c4 02 0f 85 9b 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90000117a58 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000022f4d RCX: 0000000000000001 RDX: 1ffff11002bcac80 RSI: ffffffff8a6c83a0 RDI: ffffffff8ac811a0 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2309dd0 R10: ffffffff9184ee87 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8c9a72c0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:303 [inline] rcu_read_lock include/linux/rcupdate.h:749 [inline] batadv_nc_process_nc_paths.part.0+0xd8/0x3f0 net/batman-adv/network-coding.c:687 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline] batadv_nc_worker+0xd5b/0x10f0 net/batman-adv/network-coding.c:728 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304