rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=df54/1/0x4000000000000002 softirq=116286/116286 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18696/1:b..l P18606/1:b..l P18697/1:b..l P15517/1:b..l rcu: (detected by 0, t=10502 jiffies, g=136237, q=185 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:debug_object_deactivate+0x2e4/0x3b0 lib/debugobjects.c:952 Code: f3 fd ff ff 44 39 25 7b 6d fb 0b 7d d6 44 89 25 72 6d fb 0b eb cd 83 f8 04 0f 84 47 ff ff ff 48 89 ce 48 89 d7 e8 dc ba 94 06 c8 fd ff ff c7 43 10 02 00 00 00 eb e7 48 89 0c 24 48 89 54 24 RSP: 0018:ffffc90000a08db0 EFLAGS: 00000082 RAX: 0000000080010002 RBX: ffff88807ba92bd0 RCX: 0000000000000000 RDX: 0000000000010003 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffc90000a08e88 R08: 0000000000000000 R09: fffffbfff3725765 R10: ffffffff9b92bb2b R11: 0000000000000000 R12: 0000000000000001 R13: dffffc0000000000 R14: ffff88807efde300 R15: 1ffff920001411b8 FS: 0000000000000000(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000d000 CR3: 0000000069d08000 CR4: 00000000003526f0 Call Trace: debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline] __run_hrtimer kernel/time/hrtimer.c:2000 [inline] __hrtimer_run_queues+0x2e9/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:finish_task_switch.isra.0+0x2cd/0x10c0 kernel/sched/core.c:5361 Code: ab 0a 00 00 41 c7 87 20 0e 00 00 00 00 00 00 e9 47 04 00 00 49 8d 7f 48 e8 40 34 e6 09 e8 5b ad 3c 00 fb 48 8d bb f8 16 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 RSP: 0018:ffffc90000197c30 EFLAGS: 00000202 RAX: 00000000084df23b RBX: ffff88801eac2540 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e1a29fc RDI: ffff88801eac3c38 RBP: ffffc90000197c88 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff81d5704c R12: ffff88802d098000 R13: 0000000000000001 R14: ffffffff91225964 R15: ffff8880b853b4c0 context_switch kernel/sched/core.c:5513 [inline] __schedule+0x1264/0x6730 kernel/sched/core.c:7234 schedule_idle+0x54/0x80 kernel/sched/core.c:7352 do_idle+0x35e/0x5b0 kernel/sched/idle.c:384 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x158 task:udevd state:R running task stack:24840 pid:15517 tgid:15517 ppid:4977 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0xc/0x20 kernel/kcov.c:300 Code: 00 e9 b8 fe ff ff 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 48 8b 0c 24 40 0f b6 d6 <40> 0f b6 f7 bf 01 00 00 00 e9 86 fe ff ff 66 0f 1f 44 00 00 90 90 RSP: 0000:ffffc90010127910 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff82be3569 RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff888066d03f00 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: ffff888066d03f00 R14: ffff888037744000 R15: ffff88807ac6f920 rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] kernfs_root+0x119/0x2a0 fs/kernfs/kernfs-internal.h:76 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:110 [inline] kernfs_rcu_name fs/kernfs/kernfs-internal.h:120 [inline] kernfs_dop_revalidate+0x63c/0x7e0 fs/kernfs/dir.c:1229 d_revalidate fs/namei.c:1035 [inline] d_revalidate fs/namei.c:1031 [inline] lookup_fast+0x3c7/0x600 fs/namei.c:1881 walk_component fs/namei.c:2278 [inline] link_path_walk+0x7d4/0x1cc0 fs/namei.c:2656 path_lookupat+0x74/0xc40 fs/namei.c:2812 filename_lookup+0x202/0x590 fs/namei.c:2842 vfs_statx+0xff/0x3f0 fs/stat.c:353 vfs_fstatat+0x77/0xe0 fs/stat.c:373 __do_sys_newfstatat+0x9d/0x120 fs/stat.c:538 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4749911b0a RSP: 002b:00007ffd309319e8 EFLAGS: 00000202 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffd30932f10 RCX: 00007f4749911b0a RDX: 00007ffd309319f0 RSI: 00007ffd30931a80 RDI: 00000000ffffff9c RBP: 0000558298bc14e0 R08: 00007ffd30932f10 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000202 R12: 0000558298bc15d0 R13: 00007ffd30931a80 R14: 0000558298bb18d0 R15: 00007ffd30933710 task:syz.9.3205 state:R running task stack:26696 pid:18697 tgid:18697 ppid:15537 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1964 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x16f7/0x4a30 mm/memory.c:2109 unmap_vmas+0x299/0x5f0 mm/memory.c:2178 exit_mmap+0x1ef/0xa00 mm/mmap.c:1300 __mmput+0x12a/0x410 kernel/fork.c:1187 mmput+0x67/0x80 kernel/fork.c:1210 exit_mm kernel/exit.c:610 [inline] do_exit+0x8b1/0x2ae0 kernel/exit.c:992 do_group_exit+0xd5/0x2a0 kernel/exit.c:1147 __do_sys_exit_group kernel/exit.c:1158 [inline] __se_sys_exit_group kernel/exit.c:1156 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1156 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb83179de59 RSP: 002b:00007fffb6360f28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb83179de59 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffb6360f8c R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000085 R13: 00000000000927c0 R14: 000000000010d75d R15: 00007fffb6360fe0 task:syz.9.3186 state:R running task stack:22952 pid:18606 tgid:18606 ppid:15537 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 3b df 7d 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 86 c4 3c 0f 0f 82 ac 02 00 00 8b 35 4e f8 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd de 7d 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0018:ffffc90004e67158 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e17cd15 RDI: ffffffff8c400c80 RBP: ffffffff8ebe6100 R08: 00000000ffffffff R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] page_ext_get+0x36/0x1a0 mm/page_ext.c:531 __reset_page_owner+0x2b/0x190 mm/page_owner.c:306 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xa44/0x1710 mm/page_alloc.c:3011 folios_put_refs+0x585/0xaa0 mm/swap.c:1057 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x3a5/0xbe0 mm/shmem.c:1407 evict+0x3c2/0xad0 fs/inode.c:825 iput_final fs/inode.c:2019 [inline] iput.part.0+0x989/0x1050 fs/inode.c:2068 iput+0x35/0x40 fs/inode.c:2034 dentry_unlink_inode+0x284/0x470 fs/dcache.c:479 dentry_kill+0x25d/0xc20 fs/dcache.c:826 finish_dput fs/dcache.c:1001 [inline] dput.part.0+0xd7/0x240 fs/dcache.c:1042 dput+0x1f/0x30 fs/dcache.c:1037 __fput+0x519/0xb50 fs/file_table.c:520 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x951/0x2ae0 kernel/exit.c:1004 do_group_exit+0xd5/0x2a0 kernel/exit.c:1147 get_signal+0x1ec7/0x21e0 kernel/signal.c:3038 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x402/0xa00 kernel/entry/common.c:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fb831653b27 RSP: 002b:00007fb8325c51a0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fb83179de59 RDX: 00007fb8325c51c0 RSI: 00007fb8325c52f0 RDI: 000000000000000b RBP: 00007fb831833e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fb831a26038 R14: 00007fb831a25fa0 R15: 00007fffb6360be8 task:syz.6.3204 state:R running task stack:25752 pid:18696 tgid:18695 ppid:15523 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] finish_fault+0x8e8/0x1400 mm/memory.c:5730 do_read_fault mm/memory.c:5864 [inline] do_fault+0xac5/0x1750 mm/memory.c:5994 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6379 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6517 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1178/0x32a0 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x107/0x3a0 mm/gup.c:1963 mm_populate include/linux/mm.h:4171 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0xe4/0x610 mm/mmap.c:606 __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/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4c7819de59 RSP: 002b:00007f4c79081028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f4c78425fa0 RCX: 00007f4c7819de59 RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f4c78233e6f R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4c78426038 R14: 00007f4c78425fa0 R15: 00007ffd77971ca8 rcu: rcu_preempt kthread starved for 10502 jiffies! g136237 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:28984 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 06 8e 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 d9 12 00 fb f4 bc 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e807e10 EFLAGS: 00000246 RAX: 0000000007f1a409 RBX: ffffffff8e891480 RCX: ffffffff8bb8c2d5 RDX: 0000000000000000 RSI: ffffffff8e1a29fc RDI: ffffffff8c400c80 RBP: fffffbfff1d12290 R08: 0000000000000001 R09: ffffed101708678d R10: ffff8880b8433c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1d00fc6 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c356aa4 CR3: 0000000033f3f000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x251/0x260 init/main.c:717 start_kernel+0x48e/0x490 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158