rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=8dd4/1/0x4000000000000000 softirq=41356/41357 fqs=4 rcu: (detected by 1, t=10502 jiffies, g=31769, q=222 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11049 Comm: syz.3.1343 Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:227 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:570 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1116 [inline] RIP: 0010:trace_hrtimer_cancel+0x5f/0x220 include/trace/events/timer.h:317 Code: 00 00 e8 44 d0 12 00 89 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 10 49 62 90 e8 29 ed 75 00 48 0f a3 1d 81 6a bb 0e <0f> 92 c3 31 ff 89 de e8 b5 ca 12 00 84 db 0f 85 0e 01 00 00 5b 5d RSP: 0018:ffffc90000007e10 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81a6de87 RDX: fffffbfff20c4923 RSI: 0000000000000008 RDI: ffffffff90624910 RBP: ffff888034b2b340 R08: 0000000000000000 R09: fffffbfff20c4922 R10: ffffffff90624917 R11: 0000000000000003 R12: ffff888034b2b340 R13: ffff8880b862c780 R14: ffff8880b862c680 R15: ffffffff89690890 FS: 00007fe7017156c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000003080e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_deactivate kernel/time/hrtimer.c:476 [inline] __run_hrtimer kernel/time/hrtimer.c:1706 [inline] __hrtimer_run_queues+0x484/0xae0 kernel/time/hrtimer.c:1802 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1864 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:__sanitizer_cov_trace_pc+0x5a/0x70 kernel/kcov.c:223 Code: 35 8b 82 2c 16 00 00 85 c0 74 2b 8b 82 08 16 00 00 83 f8 02 75 20 48 8b 8a 10 16 00 00 8b 92 0c 16 00 00 48 8b 01 48 83 c0 01 <48> 39 d0 73 07 48 89 01 48 89 34 c1 c3 cc cc cc cc 0f 1f 44 00 00 RSP: 0018:ffffc9000b4cf4f0 EFLAGS: 00000216 RAX: 0000000000080000 RBX: ffff8881497f0b02 RCX: ffffc9000c9c9000 RDX: 0000000000080000 RSI: ffffffff8b53a7d7 RDI: 0000000000000007 RBP: ffffc9000b4cf568 R08: 0000000000000007 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000019 R13: ffff888060fcb440 R14: 0000000000000002 R15: 0000000000000001 xas_descend lib/xarray.c:218 [inline] xas_load+0x1e7/0x5b0 lib/xarray.c:246 filemap_get_entry+0x10a/0x3c0 mm/filemap.c:1860 shmem_get_folio_gfp+0x221/0x1530 mm/shmem.c:2446 shmem_fault+0x200/0xae0 mm/shmem.c:2723 __do_fault+0x10a/0x490 mm/memory.c:4977 do_read_fault mm/memory.c:5392 [inline] do_fault mm/memory.c:5526 [inline] do_pte_missing+0xecf/0x3e10 mm/memory.c:4047 handle_pte_fault mm/memory.c:5889 [inline] __handle_mm_fault+0x1166/0x2c60 mm/memory.c:6032 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6201 faultin_page mm/gup.c:1196 [inline] __get_user_pages+0x773/0x36f0 mm/gup.c:1491 populate_vma_page_range+0x27f/0x3a0 mm/gup.c:1929 __mm_populate+0x1d6/0x380 mm/gup.c:2032 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x2d3/0x3a0 mm/util.c:580 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 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: 0033:0x7fe70098cd29 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:00007fe701715038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fe700ba5fa0 RCX: 00007fe70098cd29 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007fe700a0e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe700ba5fa0 R15: 00007ffd5c358538 rcu: rcu_preempt kthread starved for 10494 jiffies! g31769 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:27456 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 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: 8052 Comm: kworker/u8:13 Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4ea/0x12c0 kernel/smp.c:885 Code: fc 04 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 ff 83 e0 01 41 89 c5 89 c6 e8 d6 ff 0b 00 <45> 85 ed 75 d0 e8 cc 04 0c 00 e8 c7 04 0c 00 44 8b 6c 24 04 bf 07 RSP: 0018:ffffc9000c3e7928 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b86469c0 RCX: ffffffff81ada9da RDX: ffff88802502a440 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170c8d39 R13: 0000000000000001 R14: ffff8880b873fe40 R15: ffff8880b86469c8 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c27513e 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:2114 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_flush arch/x86/kernel/alternative.c:2512 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522 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:849 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:841 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 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