rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=bd4c/1/0x4000000000000000 softirq=22148/22155 fqs=524 rcu: (detected by 0, t=10502 jiffies, g=35581, q=384 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2840 Comm: kworker/u4:9 Not tainted 6.7.0-next-20240119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:207 Code: c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 15 f4 9f 77 7e <65> 8b 05 f5 9f 77 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0018:ffffc900001f0df0 EFLAGS: 00000002 RAX: 0000000080010001 RBX: ffff88803121b340 RCX: ffffffff817a4904 RDX: ffff88802cfdbb80 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880b952bbc0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000004 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880b952bac0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000003076a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_hrtimer+0x8d/0x290 kernel/time/hrtimer.c:1119 __run_hrtimer kernel/time/hrtimer.c:1668 [inline] __hrtimer_run_queues+0x577/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x10f/0x410 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:207 Code: c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 15 f4 9f 77 7e <65> 8b 05 f5 9f 77 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0018:ffffc9000bd77ba0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff8a7f8c88 RDX: ffff88802cfdbb80 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000046 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: ffff888023fb9400 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000001 rcu_read_unlock include/linux/rcupdate.h:782 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x8d8/0x10f0 net/batman-adv/network-coding.c:719 process_one_work+0x8d5/0x16e0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2707 [inline] worker_thread+0x8b6/0x1290 kernel/workqueue.c:2788 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 rcu: rcu_preempt kthread starved for 7642 jiffies! g35581 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:26192 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf15/0x5ce0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe7/0x280 kernel/sched/core.c:6817 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2183 rcu_gp_fqs_loop+0x1eb/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x245/0x380 kernel/rcu/tree.c:1830 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-next-20240119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:113 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 38 07 4b 75 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 08 51 a1 00 fb f4 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8d207d68 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8ab89e69 RDX: 0000000000000001 RSI: ffff888017ae9800 RDI: ffff888017ae9864 RBP: ffff888017ae9864 R08: 0000000000000001 R09: ffffed1017286ded R10: ffff8880b9436f6b R11: 0000000000000000 R12: ffff88801571f000 R13: ffffffff8e11bc20 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556c2f938 CR3: 000000002e4f2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:707 cpuidle_enter_state+0x85/0x510 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:388 cpuidle_idle_call kernel/sched/idle.c:215 [inline] do_idle+0x318/0x3f0 kernel/sched/idle.c:312 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:410 rest_init+0x16f/0x2b0 init/main.c:730 arch_call_rest_init+0x13/0x40 init/main.c:827 start_kernel+0x39e/0x480 init/main.c:1072 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x170/0x17b