rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=5334/1/0x4000000000000000 softirq=13294/13294 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=9117, q=353 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6196 Comm: dhcpcd-run-hook Not tainted 6.12.0-next-20241128-syzkaller-12916-gf486c8aa16b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__lock_acquire+0xc6a/0x2100 kernel/locking/lockdep.c:5196 Code: f6 85 c0 0f 84 da 07 00 00 48 c7 c0 c0 b9 3c 9a 48 c1 e8 03 48 bf 00 00 00 00 00 fc ff df 0f b6 04 38 84 c0 0f 85 24 0d 00 00 <83> 3d af f8 c1 18 00 75 39 48 63 9c 24 88 00 00 00 48 89 d8 48 c1 RSP: 0018:ffffc90000007a10 EFLAGS: 00000097 RAX: 0000000000000004 RBX: 1ffff1100e248525 RCX: ffffffff9a3cb903 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff888071242908 R08: ffffffff942c4997 R09: 1ffffffff2858932 R10: dffffc0000000000 R11: fffffbfff2858933 R12: ffff8880712428c4 R13: ffff888071241e00 R14: 0000000000000000 R15: ffff888071242928 FS: 00007f2aee4e3380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558f037da950 CR3: 000000007d9de000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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:user_mode arch/x86/include/asm/ptrace.h:214 [inline] RIP: 0010:unwind_next_frame+0xeb/0x22d0 arch/x86/kernel/unwind_orc.c:482 Code: 80 3c 20 00 74 08 48 89 ef e8 51 bd be 00 48 8b 5d 00 48 85 db 74 24 48 81 c3 88 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 c7 19 00 00 f6 03 03 0f 85 35 18 00 00 48 89 6c 24 50 RSP: 0018:ffffc90004a3edb0 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffffc90004a3f6f0 RCX: ffffffff9a3cb903 RDX: dffffc0000000000 RSI: ffffffff8bd2a48a RDI: 0000000000000001 RBP: ffffc90004a3eed0 R08: 0000000000000007 R09: ffffc90004a3ef70 R10: ffffc90004a3eed0 R11: ffffffff818b3990 R12: dffffc0000000000 R13: ffffc90004a3ee80 R14: ffffffff8bd2a48a R15: 0000000000000000 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544 __call_rcu_common kernel/rcu/tree.c:3086 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190 context_switch kernel/sched/core.c:5372 [inline] __schedule+0x1858/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:copy_mc_enhanced_fast_string+0xa/0x13 arch/x86/lib/copy_mc_64.S:130 Code: 89 ca e9 89 fd ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 89 f8 48 89 d1 a4 31 c0 c3 cc cc cc cc 48 89 c8 c3 cc cc cc cc 0f 1f 44 00 00 RSP: 0000:ffffc90004a3f718 EFLAGS: 00010246 RAX: ffff88807142d000 RBX: 0005088000000000 RCX: 0000000000000c00 RDX: 0000000000001000 RSI: ffff888071487400 RDI: ffff88807142d400 RBP: ffffc90004a3f950 R08: ffff888071487fff R09: 1ffff1100e290fff R10: dffffc0000000000 R11: ffffed100e291000 R12: ffff8880118ec600 R13: ffff888071487000 R14: ffffc90004a3fe18 R15: ffffea0001c50b40 copy_mc_user_highpage include/linux/highmem.h:343 [inline] __wp_page_copy_user mm/memory.c:3058 [inline] wp_page_copy mm/memory.c:3374 [inline] do_wp_page+0x1352/0x5160 mm/memory.c:3759 handle_pte_fault+0x1117/0x66b0 mm/memory.c:5817 __handle_mm_fault mm/memory.c:5944 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6112 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f2aee5e81a6 Code: f2 e6 0e 00 eb 81 49 89 c5 49 ff c0 49 c1 ed 0c 4c 33 28 4c 89 e8 eb c0 44 0f b7 04 4e 4c 89 c0 4d 39 d8 73 2a 48 89 fa ff c0 <4c> 89 4d 18 48 c1 ea 0c 48 33 94 ce 80 00 00 00 48 89 55 10 48 89 RSP: 002b:00007ffc3b280790 EFLAGS: 00010203 RAX: 0000000000000001 RBX: 0000000000000410 RCX: 000000000000003f RDX: 0000558f037e1b00 RSI: 0000558f037da010 RDI: 0000558f037e1b00 RBP: 0000558f037e1af0 R08: 0000000000000000 R09: baff6c8fe5a3141b R10: 00007f2aee81c088 R11: 0000000000000007 R12: 0000000000000000 R13: 0000558f037dbb70 R14: 00007f2aee712aa0 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10495 jiffies! g9117 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:26072 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: 3573 Comm: kworker/u8:7 Not tainted 6.12.0-next-20241128-syzkaller-12916-gf486c8aa16b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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 66 e9 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 11 e5 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 f5 e4 RSP: 0018:ffffc9000d57f6e0 EFLAGS: 00000293 RAX: ffffffff8193900b RBX: 1ffff110170c8c89 RCX: ffff888031f5bc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000d57f8e0 R08: ffffffff81938fda R09: 1ffffffff2858910 R10: dffffc0000000000 R11: fffffbfff2858911 R12: dffffc0000000000 R13: ffff8880b8646448 R14: ffff8880b873fac0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f88f3906d58 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:2118 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2328 text_poke_flush arch/x86/kernel/alternative.c:2519 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2526 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:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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