rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P19525/1:b..l P17707/1:b..l P12/3:b..l rcu: (detected by 1, t=10502 jiffies, g=141029, q=490 ncpus=2) task:kworker/u8:0 state:D stack:20352 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule_rtlock+0x30/0x70 kernel/sched/core.c:7347 rtlock_slowlock_locked+0x3638/0x3c80 kernel/locking/rtmutex.c:1890 rtlock_slowlock kernel/locking/rtmutex.c:1917 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] rmqueue_buddy mm/page_alloc.c:3211 [inline] rmqueue mm/page_alloc.c:3403 [inline] get_page_from_freelist+0xcae/0x2930 mm/page_alloc.c:3938 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] kmem_cache_alloc_node_noprof+0x4f4/0x6e0 mm/slub.c:4951 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1385 [inline] nlmsg_new include/net/netlink.h:1055 [inline] inet6_rt_notify+0x170/0x470 net/ipv6/route.c:6370 fib6_add_rt2node+0x1889/0x3940 net/ipv6/ip6_fib.c:1291 fib6_add+0x8e7/0x18c0 net/ipv6/ip6_fib.c:1536 __ip6_ins_rt net/ipv6/route.c:1355 [inline] ip6_route_add+0xf5/0x1d0 net/ipv6/route.c:3968 addrconf_add_mroute+0x2d1/0x370 net/ipv6/addrconf.c:2552 addrconf_add_dev net/ipv6/addrconf.c:2570 [inline] addrconf_dev_config net/ipv6/addrconf.c:3484 [inline] addrconf_init_auto_addrs+0x4d7/0xa50 net/ipv6/addrconf.c:3572 addrconf_notify+0xb1e/0x1050 net/ipv6/addrconf.c:3752 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 netif_state_change+0x27d/0x3a0 net/core/dev.c:1603 __linkwatch_run_queue+0x575/0x850 net/core/link_watch.c:240 linkwatch_event+0x4c/0x60 net/core/link_watch.c:314 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 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 task:kworker/u8:1 state:D stack:21032 pid:17707 tgid:17707 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound nsim_dev_trap_report_work Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule_rtlock+0x30/0x70 kernel/sched/core.c:7347 rtlock_slowlock_locked+0x3638/0x3c80 kernel/locking/rtmutex.c:1890 rtlock_slowlock kernel/locking/rtmutex.c:1917 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] rmqueue_buddy mm/page_alloc.c:3211 [inline] rmqueue mm/page_alloc.c:3403 [inline] get_page_from_freelist+0xcae/0x2930 mm/page_alloc.c:3938 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_node_track_caller_noprof+0x60b/0x7e0 mm/slub.c:5408 kmalloc_reserve net/core/skbuff.c:635 [inline] __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1385 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29f/0xbd0 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 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 task:syz-executor state:R running task stack:22280 pid:19525 tgid:19525 ppid:19510 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 11 5e 7b 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 cb 58 c9 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 28 65 eb RSP: 0018:ffffc90005337220 EFLAGS: 00000282 RAX: 3c210e780f8b3a00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000937bd749 RSI: ffffffff8d85fbba RDI: ffffffff8ba75ce0 RBP: ffffffff81adf9dd R08: ffffffff81adf9dd R09: ffffffff8dfc8100 R10: ffffc90005337338 R11: ffffffff81af87f0 R12: 0000000000000002 R13: ffffffff8dfc8100 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] is_module_text_address+0x39/0x1e0 kernel/module/main.c:3921 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26 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:1397 [inline] free_unref_folios+0xd8d/0x1990 mm/page_alloc.c:2999 folios_put_refs+0x7cb/0x8d0 mm/swap.c:1008 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x289/0xae0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:841 filename_unlinkat+0x445/0x610 fs/namei.c:5582 __do_sys_unlink fs/namei.c:5613 [inline] __se_sys_unlink+0x2e/0x140 fs/namei.c:5610 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: 0033:0x7fb0d510bf47 RSP: 002b:00007ffe05732de8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb0d510bf47 RDX: 00007ffe05732e10 RSI: 00007ffe05732ea0 RDI: 00007ffe05732ea0 RBP: 00007ffe05732ea0 R08: 00007ffe05733ea0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe05733f30 R13: 00007fb0d51a21ca R14: 00000000001eef54 R15: 00007ffe05733f70 rcu: rcu_preempt kthread timer wakeup didn't happen for 10127 jiffies! g141029 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=86742 rcu: rcu_preempt kthread starved for 10128 jiffies! g141029 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27096 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(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:63 Code: 0b 6f 02 c3 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 23 dc 2d 00 fb f4 7c cb 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8dc07dc0 EFLAGS: 00000246 RAX: 00000000021e1f71 RBX: ffffffff8199487a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d60267d RDI: ffffffff8ba75ce0 RBP: ffffffff8dc07eb0 R08: ffff8880b8833e9b R09: 1ffff110171067d3 R10: dffffc0000000000 R11: ffffed10171067d4 R12: 0000000000000000 R13: 1ffffffff1b9fdd8 R14: 0000000000000000 R15: 1ffffffff1b9fdd8 FS: 0000000000000000(0000) GS:ffff888126187000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558b1cbf5a38 CR3: 000000001b3d8000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 rest_init+0x2de/0x300 init/main.c:762 start_kernel+0x38a/0x3e0 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147