rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=4234/1/0x4000000000000000 softirq=25655/25656 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=25333, q=421 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8182 Comm: syz.9.743 Not tainted 6.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:advance_sched+0x128/0xca0 net/sched/sch_taprio.c:927 Code: 00 00 00 00 00 fc ff df 48 89 4c 24 78 80 3c 01 00 74 08 48 89 df e8 77 97 24 f8 48 89 5c 24 70 4c 8b 3b e8 1a f4 03 02 89 c3 <31> ff 89 c6 e8 5f 61 bd f7 85 db 74 2d 48 8b 44 24 08 48 8d 78 c0 RSP: 0018:ffffc90000a18c70 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff888057745a00 RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff8a046088 R09: fffff5200014317c R10: dffffc0000000000 R11: fffff5200014317c R12: 0000000000000002 R13: ffffffff8a045fb0 R14: ffff88807ed5d340 R15: ffff88802239e800 FS: 00007f793254c6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f44f6c37f98 CR3: 0000000067fc6000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x59d/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 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:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x90 kernel/kcov.c:321 Code: 44 0a 20 e9 45 7e 4e ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 0c 25 80 d6 03 00 65 8b 05 90 13 42 7e 25 00 01 ff 00 74 RSP: 0018:ffffc90002e37210 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffea0001fcee40 RCX: 1ffffd40003f9dc8 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00fff0000002010c R08: ffffffff81fb8726 R09: 1ffffd40003f9dc8 R10: dffffc0000000000 R11: fffff940003f9dc9 R12: ffffc90002e373e0 R13: 1ffffd40003f9dc9 R14: ffffea0001fcee48 R15: 00000000000003ff constant_test_bit arch/x86/include/asm/bitops.h:206 [inline] arch_test_bit arch/x86/include/asm/bitops.h:238 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] folio_test_locked include/linux/page-flags.h:510 [inline] next_uptodate_folio+0x156/0x5f0 mm/filemap.c:3640 filemap_map_pages+0x12d0/0x1900 mm/filemap.c:3821 do_fault_around mm/memory.c:5361 [inline] do_read_fault mm/memory.c:5394 [inline] do_fault mm/memory.c:5537 [inline] do_pte_missing mm/memory.c:4058 [inline] handle_pte_fault mm/memory.c:5900 [inline] __handle_mm_fault+0x4acd/0x70f0 mm/memory.c:6043 handle_mm_fault+0x3e5/0x8d0 mm/memory.c:6212 faultin_page mm/gup.c:1196 [inline] __get_user_pages+0x1a92/0x4140 mm/gup.c:1491 populate_vma_page_range+0x264/0x330 mm/gup.c:1929 __mm_populate+0x27a/0x460 mm/gup.c:2032 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x303/0x430 mm/util.c:580 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f793178d169 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:00007f793254c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f79319a5fa0 RCX: 00007f793178d169 RDX: 000000000000000f RSI: 0000000000b36000 RDI: 0000400000000000 RBP: 00007f793180e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000004008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f79319a5fa0 R15: 00007ffdb469a1a8 rcu: rcu_preempt kthread starved for 10498 jiffies! g25333 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:26104 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/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: 0 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.14.0-rc4-syzkaller #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+0x1bae/0x2d30 kernel/smp.c:885 Code: 89 e6 83 e6 01 31 ff e8 30 f5 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 e0 f0 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 03 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 bb f0 0b RSP: 0018:ffffc90000bd7640 EFLAGS: 00000293 RAX: dffffc0000000000 RBX: 1ffff110170e88f9 RCX: ffff888021aebc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000bd7840 R08: ffffffff81b5cd10 R09: 1ffffffff28a9308 R10: dffffc0000000000 R11: fffffbfff28a9309 R12: ffff8880b863fb48 R13: ffff8880b87447c8 R14: ffff8880b863fb40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c379e56 CR3: 000000000e938000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 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+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:850 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244