rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=9444/1/0x4000000000000000 softirq=179981/179981 fqs=5 rcu: (detected by 1, t=10503 jiffies, g=178865, q=181 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18762 Comm: kworker/u8:24 Not tainted 6.14.0-rc5-syzkaller-00268-g1110ce6a1e34 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:hlock_class+0x49/0x130 kernel/locking/lockdep.c:230 Code: 74 08 3c 03 0f 8e da 00 00 00 0f b7 5b 20 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 c0 5c ec 96 02 50 87 00 48 0f a3 1d 0a 96 56 15 73 13 48 69 c3 c8 00 00 00 RSP: 0018:ffffc900000079e0 EFLAGS: 00000006 RAX: 0000000000000035 RBX: 0000000000000d55 RCX: 0000000000000000 RDX: 1ffff1100904d5f4 RSI: 0000000000000008 RDI: ffffffff96ec5e68 RBP: ffffc90000007b28 R08: 0000000000000002 R09: 0000000000000001 R10: ffffffff96ec5e6f R11: 0000000000000003 R12: ffff88804826a440 R13: 0000000000000001 R14: 0000000000000000 R15: 1ffff92000000f44 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000004ed26000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_lock+0xb5/0xc60 kernel/locking/lockdep.c:4729 mark_usage kernel/locking/lockdep.c:4637 [inline] __lock_acquire+0x1390/0x3c40 kernel/locking/lockdep.c:5182 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd8/0xc60 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__local_bh_enable_ip+0xac/0x120 kernel/softirq.c:396 Code: 1d 61 ad 87 7e 65 8b 05 5a ad 87 7e a9 00 ff ff 00 74 4d bf 01 00 00 00 e8 41 db 0b 00 e8 cc 7c 45 00 fb 65 8b 05 3c ad 87 7e <85> c0 74 52 5b 5d c3 cc cc cc cc 65 8b 05 6e 5c 86 7e 85 c0 75 9e RSP: 0018:ffffc900043c7a98 EFLAGS: 00000206 RAX: 0000000080000000 RBX: 00000000fffffe00 RCX: 1ffffffff2de464a RDX: 0000000000000000 RSI: ffffffff8b6cfb00 RDI: ffffffff8bd368a0 RBP: ffffffff8b25f566 R08: 0000000000000001 R09: fffffbfff2dd8bb5 R10: ffffffff96ec5daf R11: 0000000000000002 R12: ffffffff8b25f910 R13: ffff88805a6ad500 R14: 0000000000000000 R15: ffff888024995780 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x1c6/0x390 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x94a/0x1060 net/batman-adv/network-coding.c:722 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10475 jiffies! g178865 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27552 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 29161 Comm: syz.3.6438 Not tainted 6.14.0-rc5-syzkaller-00268-g1110ce6a1e34 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4c6/0x12c0 kernel/smp.c:885 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 ac 0e 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 e8 0b 00 00 8b 43 08 31 RSP: 0018:ffffc90003b3f5c0 EFLAGS: 00000246 RAX: 0000000000080000 RBX: ffff8880b8646a00 RCX: ffffc9001785c000 RDX: 0000000000080000 RSI: ffffffff81ade234 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffed10170c8d41 R13: 0000000000000001 R14: ffff8880b873fe80 R15: ffff8880b8646a08 FS: 00007fe68e9af6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000004ed26000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x271/0x4a0 arch/x86/mm/tlb.c:1054 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:471 [inline] tlb_flush_mmu mm/mmu_gather.c:395 [inline] tlb_finish_mmu+0x3c9/0x7b0 mm/mmu_gather.c:488 vms_clear_ptes+0x560/0x770 mm/vma.c:1144 vms_clean_up_area mm/vma.c:1156 [inline] __mmap_prepare mm/vma.c:2283 [inline] __mmap_region+0x4de/0x2760 mm/vma.c:2448 mmap_region+0x1ab/0x3f0 mm/vma.c:2539 do_mmap+0xd8d/0x11b0 mm/mmap.c:561 vm_mmap_pgoff+0x203/0x3a0 mm/util.c:575 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe68db8d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe68e9af038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fe68dda5fa0 RCX: 00007fe68db8d169 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000400000000000 RBP: 00007fe68dc0e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe68dda5fa0 R15: 00007ffcd0226a98