rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=6fac/1/0x4000000000000000 softirq=92488/92492 fqs=1 rcu: (detected by 1, t=10506 jiffies, g=77457, q=346 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16405 Comm: syz.6.2849 Not tainted 6.16.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_is_held_type+0x57/0x150 kernel/locking/lockdep.c:5939 Code: 85 c0 0f 85 ce 00 00 00 65 4c 8b 25 6b 0f 4d 08 41 8b 94 24 ec 0a 00 00 85 d2 0f 85 b6 00 00 00 48 89 fd 41 89 f6 9c 8f 04 24 48 c7 c7 4c af f0 8d 4d 8d ac 24 f0 0a 00 00 45 31 ff e8 61 14 RSP: 0018:ffffc90000007d50 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88807e9ad340 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff88807e9ad300 RBP: ffff88807e9ad300 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88807cec2440 R13: 00000000ffffffff R14: 00000000ffffffff R15: ffffffff899272e0 FS: 00007f0ed2f386c0(0000) GS:ffff888124754000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000034000 CR3: 000000005ddf5000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x721/0xc80 net/sched/sch_taprio.c:929 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_count_sub+0x63/0x160 kernel/sched/core.c:5910 Code: 53 19 85 c9 75 1b 65 8b 05 9a d4 43 12 89 c2 81 e2 ff ff ff 7f 39 d3 7f 17 81 fb fe 00 00 00 76 71 f7 db 65 01 1d 7d d4 43 12 <5b> c3 cc cc cc cc 90 e8 a1 b9 4f 03 85 c0 74 51 48 c7 c0 40 3e a8 RSP: 0018:ffffc9000dd57af0 EFLAGS: 00000297 RAX: 0000000080000001 RBX: 00000000ffffffff RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff81b01ecf RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: ffffc9000dd57cb0 R14: 0000000000000000 R15: 0000000000000000 smp_call_function_single_async+0x79/0xd0 kernel/smp.c:727 rdmsr_safe_on_cpu+0x104/0x210 arch/x86/lib/msr-smp.c:179 msr_read+0x19d/0x250 arch/x86/kernel/msr.c:66 vfs_read+0x1e1/0xc60 fs/read_write.c:570 ksys_read+0x12a/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0ed218e929 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:00007f0ed2f38038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f0ed23b5fa0 RCX: 00007f0ed218e929 RDX: 0000000000019000 RSI: 0000200000032680 RDI: 0000000000000005 RBP: 00007f0ed2210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0ed23b5fa0 R15: 00007ffdf411ce88 rcu: rcu_preempt kthread starved for 10500 jiffies! g77457 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:28744 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 14484 Comm: kworker/u8:25 Not tainted 6.16.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xd7b/0x1510 kernel/smp.c:885 Code: e8 1a 17 0c 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 b7 1b 0c 00 f3 90 <41> 0f b6 06 41 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff RSP: 0018:ffffc9000b6af8a0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8443ba0 RCX: ffffffff81b0011d RDX: ffff88807c042440 RSI: ffffffff81b000f9 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000003 R14: ffffed1017088775 R15: ffff8880b853cf40 FS: 0000000000000000(0000) GS:ffff888124854000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6ea6b70f98 CR3: 000000000e382000 CR4: 00000000003526f0 DR0: 0000000000000040 DR1: 0000000000000004 DR2: 0000000000000003 DR3: 00000000000010e3 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] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2660 [inline] smp_text_poke_batch_finish+0x27b/0xdb0 arch/x86/kernel/alternative.c:2870 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x376/0x550 kernel/jump_label.c:919 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+0xfa/0x280 mm/kfence/core.c:842 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245