rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=5e4c/1/0x4000000000000000 softirq=14352/14353 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=9817, q=1666 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6070 Comm: kworker/u8:2 Not tainted 6.13.0-syzkaller-00918-g95ec54a420b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3816 [inline] RIP: 0010:validate_chain+0x126/0x5920 kernel/locking/lockdep.c:3872 Code: 04 00 00 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 80 28 2c 94 be 08 00 00 00 e8 a2 82 8a 00 48 0f a3 1d 6a b9 b0 12 <72> 66 48 c7 c0 c0 99 3c 9a 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 RSP: 0018:ffffc90000007700 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000916 RCX: ffffffff817b6f0e RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff942c29a0 RBP: ffffc90000007a00 R08: ffffffff942c29a7 R09: 1ffffffff2858534 R10: dffffc0000000000 R11: fffffbfff2858535 R12: dffffc0000000000 R13: ffff888030784750 R14: 04ea8660460b857c R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f461ad47ab8 CR3: 000000007736a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __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+0xab/0xca0 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5874 Code: 3c 3b 00 74 08 4c 89 f7 e8 05 0c 8b 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc900041afa20 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000835f56 RCX: ffffc900041afa03 RDX: 0000000000000002 RSI: ffffffff8c0aab60 RDI: ffffffff8c601d20 RBP: ffffc900041afb48 R08: ffffffff901a67b7 R09: 1ffffffff2034cf6 R10: dffffc0000000000 R11: fffffbfff2034cf7 R12: 1ffff92000835f50 R13: 0000000000000246 R14: ffffc900041afab0 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x28b/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10498 jiffies! g9817 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:26264 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 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: 3424 Comm: kworker/u8:6 Not tainted 6.13.0-syzkaller-00918-g95ec54a420b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2c60 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 46 ed 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 f1 e8 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 d5 e8 RSP: 0018:ffffc9000cb076e0 EFLAGS: 00000293 RAX: ffffffff81939c2b RBX: 1ffff110170c8c91 RCX: ffff888031350000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000cb078e0 R08: ffffffff81939bfa R09: 1ffffffff2858510 R10: dffffc0000000000 R11: fffffbfff2858511 R12: dffffc0000000000 R13: ffff8880b8646488 R14: ffff8880b873fb00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563b0ac36048 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244