rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6264 (detected by 1, t=10502 jiffies, g=22625, q=265 ncpus=2) task:syz.4.603 state:R running task stack:22416 pid:6264 ppid:4280 flags:0x00004002 Call Trace: sched_show_task+0x497/0x5b0 kernel/sched/core.c:8954 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:261 [inline] print_other_cpu_stall+0x10a9/0x1430 kernel/rcu/tree_stall.h:606 check_cpu_stall kernel/rcu/tree_stall.h:778 [inline] rcu_pending kernel/rcu/tree.c:3895 [inline] rcu_sched_clock_irq+0x88a/0x1230 kernel/rcu/tree.c:2394 update_process_times+0x143/0x1b0 kernel/time/timer.c:2072 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1501 __run_hrtimer kernel/time/hrtimer.c:1747 [inline] __hrtimer_run_queues+0x50b/0xd50 kernel/time/hrtimer.c:1811 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 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+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90004e06740 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 46d0b8a39a0a8d00 RDX: 0000000000000000 RSI: ffffffff8a8c2220 RDI: ffffffff8adf11a0 RBP: ffffc90004e06848 R08: dffffc0000000000 R09: 1ffffffff215f248 R10: dffffc0000000000 R11: fffffbfff215f249 R12: 0000000000000001 R13: 1ffff920009c0cf4 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] trace_call_bpf+0xe0/0x6b0 kernel/trace/bpf_trace.c:134 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027 perf_trace_lock_acquire+0x33f/0x3e0 include/trace/events/lock.h:24 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x452/0x4a0 kernel/locking/lockdep.c:5633 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] ieee80211_duration net/mac80211/tx.c:58 [inline] ieee80211_tx_h_calculate_duration+0x255/0x1320 net/mac80211/tx.c:1125 invoke_tx_handlers_late+0x11fa/0x1810 net/mac80211/tx.c:1900 ieee80211_tx+0x2d4/0x460 net/mac80211/tx.c:2006 __ieee80211_subif_start_xmit+0x107e/0x32a0 net/mac80211/tx.c:4275 ieee80211_subif_start_xmit+0xf1/0x4b0 net/mac80211/tx.c:4467 __netdev_start_xmit include/linux/netdevice.h:4894 [inline] netdev_start_xmit include/linux/netdevice.h:4908 [inline] xmit_one net/core/dev.c:3695 [inline] dev_hard_start_xmit+0x262/0x870 net/core/dev.c:3711 sch_direct_xmit+0x25a/0x4b0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3932 [inline] __dev_queue_xmit+0x1771/0x37c0 net/core/dev.c:4337 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: 0033:0x7f237419c819 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:00007f23750d6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f2374416090 RCX: 00007f237419c819 RDX: 0000000000000050 RSI: 00002000000011c0 RDI: 000000000000000a RBP: 00007f2374232c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2374416128 R14: 00007f2374416090 R15: 00007ffc673f0978 rcu: rcu_preempt kthread starved for 10486 jiffies! g22625 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:26864 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: 6271 Comm: syz.1.604 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:deref_stack_reg+0x19f/0x230 arch/x86/kernel/unwind_orc.c:360 Code: 20 c2 20 ca 80 fa 01 75 46 49 8d 40 08 48 39 d8 0f 97 c1 4c 39 f0 0f 96 c0 20 c8 3c 01 75 30 4c 89 c7 49 89 f7 e8 d1 07 00 00 <49> 89 c6 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 RSP: 0018:ffffc900000073f8 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: ffffc90000000000 RCX: 0000000000000001 RDX: ffffc90000007568 RSI: dffffc0000000000 RDI: ffffc90000007790 RBP: 1ffff92000000ea5 R08: ffffc90000007790 R09: ffffc90000007578 R10: dffffc0000000000 R11: fffff52000000eb1 R12: 1ffff92000000ea6 R13: 1ffff92000000ea7 R14: ffffc90000008000 R15: dffffc0000000000 FS: 00007f3ba6bb36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2898f0 CR3: 00000000744c6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: unwind_next_frame+0x1758/0x20b0 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 ref_tracker_alloc+0x1a3/0x4b0 lib/ref_tracker.c:91 __netdev_tracker_alloc include/linux/netdevice.h:4049 [inline] netdev_hold include/linux/netdevice.h:4078 [inline] dst_init+0xda/0x410 net/core/dst.c:52 dst_alloc+0x12a/0x160 net/core/dst.c:92 ip6_dst_alloc net/ipv6/route.c:345 [inline] icmp6_dst_alloc+0x7f/0x460 net/ipv6/route.c:3309 ndisc_send_skb+0x424/0x14e0 net/ipv6/ndisc.c:493 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3979 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 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_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1375 Code: 7c d2 e8 60 7c 78 00 eb cb 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 41 56 53 66 90 e8 84 08 dd 08 e8 1f d9 2d 00 fb 5b <41> 5e 41 5f c3 49 be 00 00 00 00 00 fc ff df 49 89 ff 48 8d 9f 58 RSP: 0018:ffffc90004f572e8 EFLAGS: 00000282 RAX: 0bfaf6d9c5f6ec00 RBX: ffff8880b8e3ab00 RCX: 0bfaf6d9c5f6ec00 RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf11a0 RBP: ffffc90004f57490 R08: ffff8880b8e3580b R09: 1ffff110171c6b01 R10: dffffc0000000000 R11: ffffed10171c6b02 R12: ffff88801af7bb80 R13: ffff88801af7bb80 R14: 1ffff110035ef7c2 R15: dffffc0000000000 __schedule+0x13ec/0x40e0 kernel/sched/core.c:6568 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 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x10d/0x120 kernel/locking/spinlock.c:194 rcu_preempt_deferred_qs_irqrestore+0x862/0xc30 kernel/rcu/tree_plugin.h:-1 rcu_read_unlock_special+0x42a/0x510 kernel/rcu/tree_plugin.h:684 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] is_bpf_text_address+0x27a/0x2a0 kernel/bpf/core.c:737 kernel_text_address+0x9c/0xd0 kernel/extable.c:125 __kernel_text_address+0x9/0x30 kernel/extable.c:79 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] btf_parse kernel/bpf/btf.c:5012 [inline] btf_new_fd+0x23b/0x780 kernel/bpf/btf.c:6914 __sys_bpf+0x612/0x780 kernel/bpf/syscall.c:5076 __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: 0033:0x7f3ba5d9c819 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:00007f3ba6bb3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3ba6016090 RCX: 00007f3ba5d9c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000012 RBP: 00007f3ba5e32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3ba6016128 R14: 00007f3ba6016090 R15: 00007ffce1957df8