rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5185/1:b..l P5942/1:b..l P5947/1:b..l rcu: (detected by 0, t=10502 jiffies, g=9401, q=300 ncpus=2) task:kworker/1:4 state:R running task stack:27080 pid:5947 tgid:5947 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline] RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline] RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1548 Code: 00 00 48 c7 c7 a8 7a 89 90 e8 57 77 05 f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 a5 68 2a f8 58 48 85 db 0f 85 d4 0f 00 00 c6 6d 2a f8 8b 1d 10 ec f4 06 41 89 dc 31 ff 41 83 e4 01 44 89 RSP: 0018:ffffc900035a7ad8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff899499c9 RDX: ffff888026ca0000 RSI: ffffffff899499d8 RDI: 0000000000000007 RBP: ffffffff9b0a792c R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888026ca0b30 R12: ffff88814ce00000 R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001770 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 task:syz-executor state:R running task stack:23896 pid:5942 tgid:5942 ppid:5938 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5945 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 5c 80 3a 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 87 2c 03 00 45 31 ed eb RSP: 0018:ffffc900042d7ae8 EFLAGS: 00000286 RAX: 0000000000000046 RBX: ffff88802c740b58 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8daa967a RDI: ffffffff8bf2b580 RBP: ffffffff8e3c96a0 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000001000 R11: ffff88802c740b30 R12: ffff88802c740000 R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000001 lookup_page_ext+0x6e/0x100 mm/page_ext.c:254 page_ext_iter_begin include/linux/page_ext.h:132 [inline] __page_table_check_zero+0x150/0x4a0 mm/page_table_check.c:139 page_table_check_free include/linux/page_table_check.h:43 [inline] free_pages_prepare mm/page_alloc.c:1434 [inline] __free_frozen_pages+0x7d0/0x1170 mm/page_alloc.c:2973 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_lru_noprof+0x262/0x770 mm/slub.c:5282 sock_alloc_inode+0x25/0x1c0 net/socket.c:322 alloc_inode+0x64/0x240 fs/inode.c:346 new_inode_pseudo include/linux/fs.h:2964 [inline] sock_alloc+0x40/0x280 net/socket.c:637 __sock_create+0xc2/0x8a0 net/socket.c:1569 sock_create net/socket.c:1663 [inline] __sys_socket_create net/socket.c:1700 [inline] __sys_socket+0x14d/0x260 net/socket.c:1747 __do_sys_socket net/socket.c:1761 [inline] __se_sys_socket net/socket.c:1759 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9990d91667 RSP: 002b:00007ffddb65e7f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9990d91667 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000010 RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000050012 R13: 00007ffddb65e820 R14: 00007f9991b146a4 R15: 00007f9991b14620 task:udevd state:R running task stack:26320 pid:5185 tgid:5185 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7047 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 sock_def_readable+0x15b/0x5d0 net/core/sock.c:3611 __netlink_sendskb net/netlink/af_netlink.c:1263 [inline] netlink_sendskb net/netlink/af_netlink.c:1269 [inline] netlink_unicast+0x75f/0x870 net/netlink/af_netlink.c:1359 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c122a7407 RSP: 002b:00007fff7d0ffc50 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3c1294d880 RCX: 00007f3c122a7407 RDX: 0000000000000000 RSI: 00007fff7d0ffcb0 RDI: 0000000000000004 RBP: 000055f08e69b290 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000007c R13: 000055f08e45ed80 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10577 jiffies! g9401 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:29104 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 26 5f 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 13 99 11 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6 RAX: 000000000009fdcd RBX: 0000000000000001 RCX: ffffffff8b78c6d9 RDX: 0000000000000000 RSI: ffffffff8dacf709 RDI: ffffffff8bf2b580 RBP: ffffed1003b57498 R08: 0000000000000001 R09: ffffed10170a673d R10: ffff8880b85339eb R11: ffff88801dabaff0 R12: 0000000000000001 R13: ffff88801daba4c0 R14: ffffffff9088cdd0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881249f1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000002 CR3: 0000000076cb9000 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+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148