rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21368/1:b.el (detected by 1, t=10503 jiffies, g=116045, q=286 ncpus=2) task:syz.2.4327 state:R running task stack:23360 pid:21368 ppid:16614 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6731 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6755 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __local_bh_enable_ip+0x147/0x1c0 kernel/softirq.c:428 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:861 [inline] __dev_queue_xmit+0x1cd2/0x37c0 net/core/dev.c:4411 dev_queue_xmit include/linux/netdevice.h:3051 [inline] __bpf_tx_skb net/core/filter.c:2134 [inline] __bpf_redirect_common net/core/filter.c:2182 [inline] __bpf_redirect+0xbdf/0x1180 net/core/filter.c:2189 ____bpf_clone_redirect net/core/filter.c:2473 [inline] bpf_clone_redirect+0x30b/0x4a0 net/core/filter.c:2436 bpf_prog_c6f54bbad6dab1ee+0x56/0x5b bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:607 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_test_run+0x2b6/0x830 net/bpf/test_run.c:402 bpf_prog_test_run_skb+0xaa6/0x12a0 net/bpf/test_run.c:1191 bpf_prog_test_run+0x31e/0x390 kernel/bpf/syscall.c:3695 __sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5049 __do_sys_bpf kernel/bpf/syscall.c:5135 [inline] __se_sys_bpf kernel/bpf/syscall.c:5133 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe31579cdd9 RSP: 002b:00007fe316638028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fe315a15fa0 RCX: 00007fe31579cdd9 RDX: 0000000000000050 RSI: 00002000000011c0 RDI: 000000000000000a RBP: 00007fe315832d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe315a16038 R14: 00007fe315a15fa0 R15: 00007ffd08850cb8 rcu: rcu_preempt kthread starved for 10450 jiffies! g116045 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:27248 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 21359 Comm: syz.0.4323 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 9f b0 01 03 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc900000074a0 EFLAGS: 00000046 RAX: 00000000000000f9 RBX: 00000000000000f9 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 00000000000000f9 RDI: 0000000000000838 RBP: 0000000000000000 R08: ffffffff8e1ff42f R09: 1ffffffff1c3fe85 R10: dffffc0000000000 R11: fffffbfff1c3fe86 R12: dffffc0000000000 R13: 0000000010000a10 R14: ffffffff8c653b40 R15: dffffc0000000000 FS: 00007f45af8f26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000004000 CR3: 00000000640d9000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:478 clockevents_program_event+0x1bc/0x310 kernel/time/clockevents.c:334 hrtimer_interrupt+0x59d/0x9c0 kernel/time/hrtimer.c:1886 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 2f dd 20 f7 65 8b 05 80 60 ca 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90000007720 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: d8a39ebed893bf00 RDX: dffffc0000000000 RSI: ffffffff8a8c1120 RDI: 0000000000000001 RBP: ffffc900000077a0 R08: ffffffff90af930f R09: 1ffffffff215f261 R10: dffffc0000000000 R11: fffffbfff215f262 R12: dffffc0000000000 R13: ffff888068051c80 R14: ffffffff96e11c28 R15: 1ffff92000000ee4 __debug_check_no_obj_freed lib/debugobjects.c:988 [inline] debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1009 slab_free_hook mm/slub.c:1704 [inline] slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x290 mm/slub.c:3709 llc_rcv+0x755/0xc60 net/llc/llc_input.c:-1 __netif_receive_skb_list_ptype net/core/dev.c:5667 [inline] __netif_receive_skb_list_core+0x6e6/0x750 net/core/dev.c:5710 __netif_receive_skb_list net/core/dev.c:5762 [inline] netif_receive_skb_list_internal+0x93f/0xca0 net/core/dev.c:5853 netif_receive_skb_list+0x51/0x4e0 net/core/dev.c:5905 ieee80211_rx_napi+0x357/0x3d0 net/mac80211/rx.c:5342 ieee80211_rx include/net/mac80211.h:4849 [inline] ieee80211_handle_queued_frames+0x105/0x1b0 net/mac80211/main.c:317 tasklet_action_common+0x2fe/0x4d0 kernel/softirq.c:827 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 2f dd 20 f7 65 8b 05 80 60 ca 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000e96f280 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: d8a39ebed893bf00 RDX: dffffc0000000000 RSI: ffffffff8a8c1120 RDI: 0000000000000001 RBP: ffffc9000e96f308 R08: ffffffff90af930f R09: 1ffffffff215f261 R10: dffffc0000000000 R11: fffffbfff215f262 R12: dffffc0000000000 R13: ffff888064208000 R14: ffffffff96e6cba0 R15: 1ffff92001d2de50 __debug_check_no_obj_freed lib/debugobjects.c:988 [inline] debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1009 free_pages_prepare mm/page_alloc.c:1492 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x2a6/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 ____kasan_kmalloc mm/kasan/common.c:341 [inline] __kasan_kmalloc+0x1e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc+0xb0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] tomoyo_realpath_from_path+0xdf/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x212/0x440 security/tomoyo/file.c:771 security_file_open+0x5e/0xa0 security/security.c:1682 do_dentry_open+0x305/0x10d0 fs/open.c:869 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f45ae99cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f45af8f2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f45aec15fa0 RCX: 00007f45ae99cdd9 RDX: 000000000000275a RSI: 00002000000000c0 RDI: 000000000000000c RBP: 00007f45aea32d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f45aec16038 R14: 00007f45aec15fa0 R15: 00007ffef51a4fb8