rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ffec/1/0x4000000000000000 softirq=8947/8964 fqs=43 (detected by 0, t=10502 jiffies, g=7785, q=857 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3625 Comm: kworker/u4:5 Not tainted 6.1.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: bat_events batadv_tt_purge RIP: 0010:__lock_acquire+0x117b/0x1f80 kernel/locking/lockdep.c:5045 Code: 00 fc ff df 0f b6 04 38 84 c0 0f 85 56 0c 00 00 83 3d 18 c8 5e 10 00 0f 84 c5 01 00 00 31 db 48 83 c3 40 48 89 d8 48 c1 e8 03 <80> 3c 38 00 74 12 48 89 df e8 67 93 77 00 48 bf 00 00 00 00 00 fc RSP: 0018:ffffc900001e0a80 EFLAGS: 00000806 RAX: 1ffffffff203d1fc RBX: ffffffff901e8fe0 RCX: ffffffff816a7757 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: da2e616334457c0f R08: dffffc0000000000 R09: fffffbfff2093861 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888026518ad8 R13: ffff888026518000 R14: 0000000000000001 R15: 1ffff11004ca316a FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fddce8d56c6 CR3: 0000000018731000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] advance_sched+0x6ec/0x970 net/sched/sch_taprio.c:753 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__local_bh_enable_ip+0x16c/0x1f0 kernel/softirq.c:403 Code: 8a e8 68 06 37 09 65 66 8b 05 60 84 af 7e 66 85 c0 75 57 bf 01 00 00 00 e8 a1 38 0a 00 e8 6c 34 3d 00 fb 65 8b 05 0c 54 ae 7e <85> c0 75 05 e8 3b 79 ac ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c RSP: 0018:ffffc900042bfb20 EFLAGS: 00000282 RAX: 0000000080000000 RBX: 1ffff92000857f68 RCX: ffffffff816acf0a RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: ffffffff8b3d45e0 RBP: ffffc900042bfbc8 R08: dffffc0000000000 R09: fffffbfff2093861 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff92000857f6c R14: ffffc900042bfb60 R15: 0000000000000201 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2299 [inline] batadv_tt_purge+0x4dc/0xa40 net/batman-adv/translation-table.c:3561 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:308 rcu: rcu_preempt kthread starved for 10408 jiffies! g7785 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:26136 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 14 Comm: kworker/0:1 Not tainted 6.1.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events fqdir_free_fn RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_single+0x4a3/0x2680 kernel/smp.c:787 Code: b6 04 23 84 c0 0f 85 70 01 00 00 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 1c 8d 0b 00 41 83 e5 01 75 07 e8 b1 89 0b 00 eb 3e f3 90 <42> 0f b6 04 23 84 c0 75 10 41 f7 06 01 00 00 00 74 25 e8 96 89 0b RSP: 0018:ffffc90000137820 EFLAGS: 00000293 RAX: ffffffff817f03ba RBX: 1ffff92000026f21 RCX: ffff88813fed9dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000137ba0 R08: ffffffff817f0394 R09: fffff52000026ecd R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000000001 R14: ffffc90000137908 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f596dcd0fe8 CR3: 000000007f1aa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_barrier+0x323/0x5f0 kernel/rcu/tree.c:4070 fqdir_free_fn+0x2e/0x130 net/ipv4/inet_fragment.c:166 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:308