rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=1e94/1/0x4000000000000000 softirq=19845/19846 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5835/1:b..l rcu: (detected by 1, t=10505 jiffies, g=14889, q=217 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3968 Comm: kworker/u8:8 Not tainted 6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:debug_objects_fill_pool+0x1f/0x510 lib/debugobjects.c:698 Code: 90 90 90 90 90 90 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 41 56 41 55 41 54 55 53 48 83 ec 68 48 c7 44 24 08 b3 8a b5 41 <48> 8d 5c 24 08 48 c7 44 24 10 c1 da 9d 8d 48 c1 eb 03 48 c7 44 24 RSP: 0018:ffffc90000007c68 EFLAGS: 00000092 RAX: dffffc0000000000 RBX: ffff8880b862c780 RCX: ffffffff81a71136 RDX: ffff888034a04880 RSI: ffffffff8b6fbca0 RDI: ffff8880617ae340 RBP: ffffc90000007df0 R08: 0000000000000001 R09: ffffc90000007d20 R10: 0000000000000000 R11: 0000000000000003 R12: dffffc0000000000 R13: ffff8880617ae340 R14: 1ffff92000000fa4 R15: ffffffff896a93a0 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe5e54d56c0 CR3: 0000000037092000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_activate+0x10d/0x4a0 lib/debugobjects.c:814 debug_hrtimer_activate kernel/time/hrtimer.c:455 [inline] debug_activate kernel/time/hrtimer.c:496 [inline] enqueue_hrtimer+0x25/0x3c0 kernel/time/hrtimer.c:1100 __run_hrtimer kernel/time/hrtimer.c:1818 [inline] __hrtimer_run_queues+0x903/0xae0 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:debug_lockdep_rcu_enabled+0x14/0x40 kernel/rcu/update.c:320 Code: 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 8b 05 e2 25 0b 05 85 c0 74 20 8b 05 20 58 0b 05 <85> c0 74 16 65 48 8b 05 20 a2 ac 74 8b 80 ec 0a 00 00 85 c0 0f 94 RSP: 0018:ffffc9000e7e7b18 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff88805f275c48 RCX: 00000000fba079c6 RDX: 0000000000000001 RSI: ffffffff8b6cf100 RDI: ffffffff8bd35aa0 RBP: 0000000000000389 R08: 0000000000000000 R09: fffffbfff2dd8598 R10: ffffffff96ec2cc7 R11: 0000000000000002 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000000 R15: dffffc0000000000 rcu_read_lock include/linux/rcupdate.h:850 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16f/0x1060 net/batman-adv/network-coding.c:719 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 task:syz-executor state:R running task stack:23360 pid:5835 tgid:5835 ppid:5811 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6944 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1201 [inline] copy_pmd_range mm/memory.c:1262 [inline] copy_pud_range mm/memory.c:1299 [inline] copy_p4d_range mm/memory.c:1323 [inline] copy_page_range+0x1e7f/0x5690 mm/memory.c:1421 dup_mmap kernel/fork.c:748 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm kernel/fork.c:1752 [inline] copy_process+0x7ccb/0x8c50 kernel/fork.c:2403 kernel_clone+0xfd/0x960 kernel/fork.c:2815 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958 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: 0033:0x7fe5e47839d3 RSP: 002b:00007ffd228f3728 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5e47839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055557eefd7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000019fad R15: 00007ffd228f38c0 rcu: rcu_preempt kthread starved for 10500 jiffies! g14889 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:17 tgid:17 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: 1308 Comm: kworker/u8:5 Not tainted 6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound toggle_allocation_gate 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 7c 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:ffffc90004fef928 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8646a00 RCX: ffffffff81add36a RDX: ffff888028d98000 RSI: ffffffff81add344 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170c8d41 R13: 0000000000000001 R14: ffff8880b873fe80 R15: ffff8880b8646a08 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb1f2276f98 CR3: 000000000df80000 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 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2118 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2328 text_poke_flush arch/x86/kernel/alternative.c:2519 [inline] text_poke_flush arch/x86/kernel/alternative.c:2516 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2526 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:850 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:842 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