rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5825/1:b..l rcu: (detected by 0, t=10502 jiffies, g=38621, q=176 ncpus=2) task:syz-executor state:R running task stack:22720 pid:5825 tgid:5825 ppid:5815 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: 0033:0x7fbf09d839d3 RSP: 002b:00007fffe82d0778 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbf09d839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055557a7ce7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000007e16a R15: 00007fffe82d0910 rcu: rcu_preempt kthread starved for 10502 jiffies! g38621 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:27072 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted 6.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:taprio_set_budgets+0x1eb/0x310 net/sched/sch_taprio.c:666 Code: 44 89 33 44 8b 74 24 0c 89 ee 48 83 c5 01 83 c6 01 49 83 c5 08 48 83 c3 04 44 89 f7 e8 0e 00 50 f8 41 39 ee 7e 65 89 6c 24 08 c0 05 50 f8 48 63 f5 48 83 fe 0f 0f 87 a6 00 00 00 4c 89 e8 48 RSP: 0018:ffffc90000a18d10 EFLAGS: 00000002 RAX: 0000000080010002 RBX: ffff888079670884 RCX: ffffffff8969dbf2 RDX: ffff888143ad2440 RSI: 0000000000000002 RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000004 R12: 0000000000000000 R13: ffff888079670808 R14: 0000000000000002 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3c3321 CR3: 0000000035b2c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: advance_sched+0x5e1/0xc60 net/sched/sch_taprio.c:977 __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:is_kfence_address include/linux/kfence.h:58 [inline] RIP: 0010:obj_to_index mm/slab.h:351 [inline] RIP: 0010:__memcg_slab_free_hook+0x105/0x5a0 mm/memcontrol.c:3017 Code: 49 83 c4 08 49 39 c4 0f 84 b2 02 00 00 4c 89 e0 48 c1 e8 03 80 3c 28 00 0f 85 88 03 00 00 48 8b 7c 24 08 49 8b 04 24 80 3f 00 <0f> 85 5b 03 00 00 48 8b 15 fe c9 3c 0e 48 89 c1 48 29 d1 48 81 f9 RSP: 0018:ffffc90000ab7a70 EFLAGS: 00000246 RAX: ffff88802a9bfc80 RBX: ffff88814168c8c0 RCX: 0000000000000001 RDX: ffffc90000ab7b10 RSI: ffffea0000aa6fc0 RDI: fffffbfff20c4c84 RBP: dffffc0000000000 R08: ffff88801b756980 R09: 0000000000000000 R10: ffff88814168c8e0 R11: 0000000000002ba2 R12: ffffc90000ab7b10 R13: 1ffffffff20c4c84 R14: ffffea0000aa6fc0 R15: ffffea0000aa6fc0 memcg_slab_free_hook mm/slub.c:2178 [inline] slab_free mm/slub.c:4606 [inline] kmem_cache_free+0x443/0x4d0 mm/slub.c:4711 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1058 __kfree_skb net/core/skbuff.c:1115 [inline] consume_skb net/core/skbuff.c:1346 [inline] consume_skb+0xcc/0x100 net/core/skbuff.c:1340 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x8cf/0xd00 drivers/net/netdevsim/dev.c:851 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