rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21440/1:b..l P21419/1:b..l P15141/1:b..l P21443/1:b..l rcu: (detected by 0, t=10502 jiffies, g=156637, q=1134 ncpus=1) task:syz.7.3544 state:R running task stack:24752 pid:21443 tgid:21441 ppid:19533 task_flags:0x40054c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 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+0x3f/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+0x4082/0x4f20 mm/memory.c:2109 unmap_vmas+0x390/0x550 mm/memory.c:2178 exit_mmap+0x293/0x9f0 mm/mmap.c:1300 __mmput+0x118/0x420 kernel/fork.c:1187 exit_mm+0x221/0x2d0 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6ef7f9e0d9 RSP: 002b:00007f6ef8e24028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: 0000000000000001 RBX: 00007f6ef8225fa0 RCX: 00007f6ef7f9e0d9 RDX: 0000000000000001 RSI: 0000200000001b00 RDI: 0000000000000005 RBP: 00007f6ef8035024 R08: 0000200000000140 R09: 000000000000001c R10: 0000000020000045 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6ef8226038 R14: 00007f6ef8225fa0 R15: 00007ffc44a14858 task:syz-executor state:R running task stack:22288 pid:15141 tgid:15141 ppid:15133 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 f1 7c 2e 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db 87 ca 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ab 78 6d ff cc 48 8d 3d c8 64 b8 RSP: 0018:ffffc9000d50f200 EFLAGS: 00000286 RAX: b7e75d08414bca00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000ae70feff RSI: ffffffff8e4b425c RDI: ffffffff8c4bdd80 RBP: ffffffff8177927f R08: ffffffff8177927f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 0000000000000002 R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 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:1406 [inline] free_unref_folios+0xd84/0x14a0 mm/page_alloc.c:3011 folios_put_refs+0x9e9/0xb30 mm/swap.c:1057 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1159 shmem_truncate_range mm/shmem.c:1287 [inline] shmem_evict_inode+0x280/0xa80 mm/shmem.c:1417 evict+0x624/0xb50 fs/inode.c:825 filename_unlinkat+0x43f/0x610 fs/namei.c:5589 __do_sys_unlink fs/namei.c:5620 [inline] __se_sys_unlink+0x2e/0x140 fs/namei.c:5617 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f31d1f9d1c7 RSP: 002b:00007ffdf89f8c48 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f31d1f9d1c7 RDX: 00007ffdf89f8c70 RSI: 00007ffdf89f8d00 RDI: 00007ffdf89f8d00 RBP: 00007ffdf89f8d00 R08: 00007ffdf89f9d00 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffdf89f9d90 R13: 00007f31d2034474 R14: 000000000013cea8 R15: 00007ffdf89f9dd0 task:syz.3.3539 state:R running task stack:26856 pid:21419 tgid:21418 ppid:15659 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 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+0x3f/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+0x4082/0x4f20 mm/memory.c:2109 unmap_vmas+0x390/0x550 mm/memory.c:2178 exit_mmap+0x293/0x9f0 mm/mmap.c:1300 __mmput+0x118/0x420 kernel/fork.c:1187 exit_mm+0x221/0x2d0 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc34519dd6b RSP: 002b:00007fc34604bf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007fc34519dd6b RDX: 00007fc34604cfd0 RSI: 0000000080085502 RDI: 0000000000000003 RBP: 00007fc34604cfd0 R08: 0000000000000040 R09: 00007fc34604bfc8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000012 R15: 00007fc345253882 task:cmp state:R running task stack:24424 pid:21440 tgid:21440 ppid:21371 task_flags:0x400000 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7506 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753 rcu_read_unlock include/linux/rcupdate.h:869 [inline] __page_table_check_zero+0x353/0x430 mm/page_table_check.c:145 page_table_check_free include/linux/page_table_check.h:46 [inline] __free_pages_prepare mm/page_alloc.c:1407 [inline] __free_frozen_pages+0xc2e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5741 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4931 alloc_empty_file+0x5b/0x1d0 fs/file_table.c:262 path_openat+0x8f/0x3830 fs/namei.c:4849 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faa211f40ba RSP: 002b:00007ffca685ccd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffca685cd50 RCX: 00007faa211f40ba RDX: 0000000000080000 RSI: 00007ffca685cd50 RDI: 00000000ffffff9c RBP: 00007ffca685cd40 R08: 00007ffca685cf47 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 000000000000001b R13: 00007faa211c8050 R14: 00007ffca685cf60 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10218 jiffies! g156637 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 18663 Comm: kworker/R-bond2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: bond2 bond_3ad_state_machine_handler RIP: 0010:deliver_ptype_list_skb net/core/dev.c:2505 [inline] RIP: 0010:__netif_receive_skb_core+0x268a/0x30b0 net/core/dev.c:6156 Code: 3c 42 8f f8 49 8b 1c 24 4c 39 e3 0f 84 ba 00 00 00 4c 8d 6b c0 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 79 45 0f b7 7d 00 44 89 ff 44 89 f6 e8 f2 a9 21 f8 66 45 RSP: 0018:ffffc90000007a00 EFLAGS: 00000212 RAX: 0000000000000000 RBX: ffffffff9059cd98 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007c40 R08: ffffc90000007b9f R09: ffffc90000007b30 R10: dffffc0000000000 R11: fffff52000000f74 R12: ffffffff90581760 R13: ffffffff9059cd58 R14: 000000000000dd86 R15: ffff8881a12dfbdc FS: 0000000000000000(0000) GS:ffff888124f4b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff5816ff000 CR3: 000000000e946000 CR4: 0000000000350ef0 Call Trace: __netif_receive_skb_one_core net/core/dev.c:6210 [inline] __netif_receive_skb net/core/dev.c:6325 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6676 __napi_poll+0xaa/0x330 net/core/dev.c:7735 napi_poll net/core/dev.c:7798 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7955 handle_softirqs+0x225/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] bond_3ad_state_machine_handler+0x5a7c/0x5d60 drivers/net/bonding/bond_3ad.c:2618 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 rescuer_thread+0x7b6/0x10b0 kernel/workqueue.c:3629 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245