rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P27822/1:b..l rcu: (detected by 0, t=10503 jiffies, g=127369, q=1320 ncpus=2) task:syz-executor state:R running task stack:21016 pid:27822 tgid:27822 ppid:27798 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 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:__orc_find arch/x86/kernel/unwind_orc.c:100 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x12ea/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: 00 6e 68 8b 89 de e8 55 f3 b3 ff e9 43 06 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 <48> 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 RSP: 0018:ffffc9000c487398 EFLAGS: 00000202 RAX: 000000000000000b RBX: ffffffff8fb06e24 RCX: 000000000000000b RDX: ffffffff8fb06df8 RSI: ffffffff903ae0a6 RDI: ffffffff8bbf0400 RBP: ffffffff8fb06df8 R08: 000000000000000c R09: ffffffff81738d25 R10: ffffc9000c4874b8 R11: ffffffff81ac2cb0 R12: ffffffff843fbf2c R13: ffffffff8fb06df8 R14: ffffc9000c487468 R15: 0000000000033fbf 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:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:311 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 discard_slab mm/slub.c:3317 [inline] __put_partials+0x146/0x170 mm/slub.c:3864 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3939 __slab_free+0x2b9/0x390 mm/slub.c:5913 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:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4962 [inline] slab_alloc_node mm/slub.c:5272 [inline] __do_kmalloc_node mm/slub.c:5633 [inline] __kmalloc_noprof+0x3c3/0x7f0 mm/slub.c:5646 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822 security_inode_getattr+0x12f/0x330 security/security.c:2416 vfs_getattr fs/stat.c:259 [inline] vfs_fstat fs/stat.c:281 [inline] vfs_fstatat+0xb1/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 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: 0033:0x7f55f638d6ba RSP: 002b:00007ffd6c3aa5a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f55f638d6ba RDX: 00007ffd6c3aa5b0 RSI: 00007f55f644ef62 RDI: 0000000000000003 RBP: 00007ffd6c3aa5b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000206 R12: 00007ffd6c3ab7b0 R13: 00007f55f6411d7d R14: 00000000000cbaa4 R15: 00007ffd6c3ab7f0 rcu: rcu_preempt kthread starved for 2008 jiffies! g127369 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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: 5149 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: krxrpcd rxrpc_peer_keepalive_worker RIP: 0010:__raw_read_unlock_irqrestore include/linux/rwlock_api_smp.h:242 [inline] RIP: 0010:_raw_read_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:268 Code: 74 05 e8 3b 16 7f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b3 44 47 f6 65 8b 05 3c 73 25 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90000006f20 EFLAGS: 00000206 RAX: 0b6665e38e8bf500 RBX: 0000000000000a06 RCX: 0b6665e38e8bf500 RDX: 0000000000000002 RSI: ffffffff8d70c9b0 RDI: 0000000000000001 RBP: ffffc90000006fb0 R08: ffffffff8f7cd377 R09: 1ffffffff1ef9a6e R10: dffffc0000000000 R11: fffffbfff1ef9a6f R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff8f32ed80 R15: 1ffff92000000de4 FS: 0000000000000000(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3a2188e9c CR3: 000000000dd38000 CR4: 00000000003526f0 Call Trace: netlink_lock_table net/netlink/af_netlink.c:454 [inline] netlink_broadcast_filtered+0x111/0x1000 net/netlink/af_netlink.c:1532 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2595 br_fdb_update+0x4c8/0x690 net/bridge/br_fdb.c:1036 br_handle_frame_finish+0x587/0x1c50 net/bridge/br_input.c:144 br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x999/0xd60 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:442 __netif_receive_skb_core+0x10b9/0x4380 net/core/dev.c:5966 __netif_receive_skb_one_core net/core/dev.c:6077 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6192 process_backlog+0x60e/0x14f0 net/core/dev.c:6544 __napi_poll+0xc7/0x360 net/core/dev.c:7594 napi_poll net/core/dev.c:7657 [inline] net_rx_action+0x5f7/0xdf0 net/core/dev.c:7784 handle_softirqs+0x286/0x870 kernel/softirq.c:622 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] rxrpc_peer_keepalive_worker+0x45a/0xde0 net/rxrpc/peer_event.c:337 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 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