rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5978/1:b..l P50/1:b..l P9366/1:b..l rcu: (detected by 1, t=10502 jiffies, g=35621, q=397 ncpus=2) task:syz-executor state:R running task stack:27496 pid:9366 tgid:9366 ppid:6697 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7171 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3b0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5894 [inline] __kmalloc_noprof+0x41d/0x800 mm/slub.c:5906 kmalloc_noprof include/linux/slab.h:972 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:827 tomoyo_path_symlink+0xa3/0xe0 security/tomoyo/tomoyo.c:212 security_path_symlink+0x177/0x380 security/security.c:1476 do_symlinkat+0x12f/0x6d0 fs/namei.c:5634 __do_sys_symlinkat fs/namei.c:5654 [inline] __se_sys_symlinkat fs/namei.c:5651 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:5651 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f030918ecc7 RSP: 002b:00007ffc80392848 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f030918ecc7 RDX: 00007f03092158c3 RSI: 00000000ffffff9c RDI: 00007f0309214390 RBP: 00007ffc8039288c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000077 R13: 00000000000927c0 R14: 000000000006f86a R15: 00007ffc803928e0 task:kworker/u8:3 state:R running task stack:21368 pid:50 tgid:50 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: kvfree_rcu_reclaim kfree_rcu_work Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x4d0/0x23d0 arch/x86/kernel/unwind_orc.c:520 Code: e0 07 0f 84 6d 15 00 00 83 f8 01 4c 8b 7c 24 50 48 bd 00 00 00 00 00 fc ff df 4c 8b 64 24 20 4c 8b 6c 24 48 0f 84 79 15 00 00 03 02 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 48 89 c1 48 c1 RSP: 0018:ffffc90000bb7438 EFLAGS: 00000202 RAX: 0000000000000002 RBX: ffffffff8fc3f884 RCX: ffffffff8fc3f888 RDX: ffffffff9044cef0 RSI: ffffffff9044ceba RDI: ffffffff8be09d00 RBP: dffffc0000000000 R08: 0000000000000016 R09: ffffffff8e144f60 R10: ffffc90000bb7558 R11: ffffffff81ad0f00 R12: 1ffff92000176ea1 R13: ffffc90000bb7558 R14: ffffc90000bb7508 R15: ffffffff81745df5 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2768 [inline] slab_free_freelist_hook mm/slub.c:2797 [inline] slab_free_bulk mm/slub.c:6940 [inline] kmem_cache_free_bulk+0x3fb/0xdd0 mm/slub.c:7717 kfree_bulk include/linux/slab.h:841 [inline] kvfree_rcu_bulk+0xe5/0x1b0 mm/slab_common.c:1464 kfree_rcu_work+0xed/0x170 mm/slab_common.c:1542 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 task:udevd state:R running task stack:23288 pid:5978 tgid:5978 ppid:5195 task_flags:0x400140 flags:0x00080801 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x58/0x340 kernel/locking/lockdep.c:5831 Code: 8b 05 7c 3e 04 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 7f 3e 04 11 83 f8 08 0f 83 84 01 00 00 89 c0 48 0f a3 05 28 89 04 0e <73> 0d e8 51 cf 08 00 84 c0 0f 84 cb 01 00 00 83 3d 32 b9 04 0e 00 RSP: 0018:ffffc900046ef038 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e144f60 RBP: ffffffff81745df5 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900046ef208 R11: fffff520008dde4d R12: 0000000000000002 R13: ffffffff8e144f60 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1436 [inline] free_unref_folios+0xcc0/0x13e0 mm/page_alloc.c:3033 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x1490 mm/shmem.c:1138 shmem_truncate_range mm/shmem.c:1250 [inline] shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1380 evict+0x5f4/0xae0 fs/inode.c:837 __dentry_kill+0x209/0x660 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f82c58a7407 RSP: 002b:00007ffe25b00b70 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007f82c601e880 RCX: 00007f82c58a7407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007f82c601e6e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 000055a55532d190 R14: 0000000000000008 R15: 000055a555327010 rcu: rcu_preempt kthread starved for 10616 jiffies! g35621 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:27656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: 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 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 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 e3 8f 29 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0000:ffffc90000197e20 EFLAGS: 000002c2 RAX: 0000000001006679 RBX: ffffffff8197762e RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d9a7514 RDI: ffffffff8be09d60 RBP: ffffc90000197f10 R08: ffff8880b873375b R09: 1ffff110170e66eb R10: dffffc0000000000 R11: ffffed10170e66ec R12: ffffffff8fa2daf0 R13: 1ffff11003ad4b58 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125cf7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000077f5c000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147