rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2/1:b..l P9257/1:b..l rcu: (detected by 0, t=10502 jiffies, g=35753, q=63560 ncpus=2) task:syz-executor state:R running task stack:22568 pid:9257 tgid:9257 ppid:9245 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7189 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 db fa d1 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003b262d8 EFLAGS: 00000206 RAX: f74d045356518500 RBX: 0000000000000000 RCX: f74d045356518500 RDX: 0000000000000000 RSI: ffffffff8d93798e RDI: ffffffff8bbf18e0 RBP: ffffffff81738f15 R08: 0000000000000000 R09: ffffffff81738f15 R10: ffffc90003b26498 R11: ffffffff81ac59b0 R12: 0000000000000002 R13: ffffffff8df3d6e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 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:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2948 discard_slab mm/slub.c:3320 [inline] __put_partials+0x146/0x170 mm/slub.c:3867 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3942 __slab_free+0x2b9/0x390 mm/slub.c:5916 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4965 [inline] slab_alloc_node mm/slub.c:5275 [inline] kmem_cache_alloc_noprof+0x37d/0x700 mm/slub.c:5282 __kernfs_new_node+0xd7/0x7e0 fs/kernfs/dir.c:637 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:713 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x66d/0x1110 fs/sysfs/group.c:183 internal_create_groups fs/sysfs/group.c:223 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:249 device_add_groups drivers/base/core.c:2836 [inline] device_add_attrs+0x1c4/0x5a0 drivers/base/core.c:2911 device_add+0x496/0xb50 drivers/base/core.c:3643 netdev_register_kobject+0x178/0x310 net/core/net-sysfs.c:2358 register_netdevice+0x126c/0x1ae0 net/core/dev.c:11341 xfrmi_create net/xfrm/xfrm_interface_core.c:252 [inline] xfrmi_newlink+0x49b/0x7b0 net/xfrm/xfrm_interface_core.c:855 rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3833 __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0x16e4/0x1c80 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6951 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd27f590e5c RSP: 002b:00007ffe65e52c20 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fd280314620 RCX: 00007fd27f590e5c RDX: 0000000000000044 RSI: 00007fd280314670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe65e52c74 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fd280314670 R15: 0000000000000000 task:kthreadd state:R running task stack:25160 pid:2 tgid:2 ppid:0 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7189 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0xc86/0x2390 arch/x86/kernel/unwind_orc.c:590 Code: e8 8f 92 b2 00 49 89 1f 48 8b 44 24 58 80 3c 28 00 48 8b 5c 24 70 4c 8b 6c 24 50 4c 8b 64 24 10 74 08 48 89 df e8 6a 92 b2 00 <4c> 89 23 ba 10 00 00 00 4c 89 ef 31 f6 e8 38 94 b2 00 48 8b 14 24 RSP: 0018:ffffc90000077258 EFLAGS: 00000246 RAX: 1ffff9200000ee6c RBX: ffffc90000077360 RCX: 1ffff9200000ee01 RDX: ffffffff9018b5aa RSI: 0000000000000002 RDI: ffffc900000777a0 RBP: dffffc0000000000 R08: 000000000000000c R09: ffffffff81738f15 R10: ffffc90000077378 R11: ffffffff81ac59b0 R12: ffffc900000777a8 R13: ffffc90000077378 R14: ffffc90000077328 R15: ffffc90000077370 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 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:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2948 discard_slab mm/slub.c:3320 [inline] __put_partials+0x146/0x170 mm/slub.c:3867 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3942 __slab_free+0x2b9/0x390 mm/slub.c:5916 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4965 [inline] slab_alloc_node mm/slub.c:5275 [inline] kmem_cache_alloc_node_noprof+0x43c/0x710 mm/slub.c:5327 alloc_task_struct_node kernel/fork.c:184 [inline] dup_task_struct+0x52/0x830 kernel/fork.c:873 copy_process+0x54b/0x3c00 kernel/fork.c:2012 kernel_clone+0x21e/0x840 kernel/fork.c:2609 kernel_thread+0x10d/0x160 kernel/fork.c:2670 create_kthread kernel/kthread.c:486 [inline] kthreadd+0x575/0x770 kernel/kthread.c:844 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 9547 jiffies! g35753 f0x2 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 __schedule_loop kernel/sched/core.c:6944 [inline] schedule+0x165/0x360 kernel/sched/core.c:6959 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 b3 98 1f 00 f3 0f 1e fa fb f4 c8 e7 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: 63fac164ff924500 RBX: ffffffff81969c67 RCX: 63fac164ff924500 RDX: 0000000000000001 RSI: ffffffff8d750a4b RDI: ffffffff8bbf18e0 RBP: ffffffff8dc07ea8 R08: ffff8880b8632fdb R09: 1ffff110170c65fb R10: dffffc0000000000 R11: ffffed10170c65fc R12: ffffffff8f7d4170 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a40 FS: 0000000000000000(0000) GS:ffff888125f29000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbcde7fff5c CR3: 00000000317a2000 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:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 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