INFO: rcu detected stall in fib6_run

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.1	INFO: rcu detected stall in fib6_run_gc	1				1	190d	190d	0/3	auto-obsoleted due to no activity on 2026/03/09 18:36
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P12510
	(detected by 0, t=10502 jiffies, g=46469, q=2218)
task:syz.3.2048      state:R  running task     stack:24688 pid:12510 ppid:  4195 flags:0x0000400c
Call Trace:
 <IRQ>
 sched_show_task+0x459/0x580 kernel/sched/core.c:8659
 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:233 [inline]
 print_other_cpu_stall+0xec5/0x1270 kernel/rcu/tree_stall.h:573
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x843/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:fib6_clean_node+0x0/0x540 net/ipv6/ip6_fib.c:2170
Code: 84 00 00 00 00 00 0f 1f 40 00 53 48 89 fb e8 e7 33 d6 f8 48 83 c3 c8 48 8b 3d 7c a8 e8 04 48 89 de 5b e9 23 84 1a f9 0f 1f 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00
RSP: 0018:ffffc90000007888 EFLAGS: 00000246
RAX: 1ffff92000000f43 RBX: 0000000000000000 RCX: ffff88804fcf0000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffc900000079e0
RBP: ffffc90000007a00 R08: ffff88804fcf0000 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000100 R12: ffff88801f4ed200
R13: 1ffff92000000f41 R14: dffffc0000000000 R15: ffffc90000007a10
 fib6_walk_continue+0x640/0x8c0 net/ipv6/ip6_fib.c:2115
 fib6_walk+0x149/0x290 net/ipv6/ip6_fib.c:2163
 fib6_clean_tree net/ipv6/ip6_fib.c:2243 [inline]
 __fib6_clean_all+0x25f/0x3c0 net/ipv6/ip6_fib.c:2259
 fib6_clean_all net/ipv6/ip6_fib.c:2270 [inline]
 fib6_run_gc+0x11a/0x2a0 net/ipv6/ip6_fib.c:2333
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c ee 68 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 f6 59 72 08 e8 f1 e6 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc90003bfef88 EFLAGS: 00000286
RAX: 3b0a6865dabf2900 RBX: ffff8880b903a340 RCX: 3b0a6865dabf2900
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0
RBP: 1ffff11017207613 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650
 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0xc8/0x400 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725
 kernel_text_address kernel/extable.c:151 [inline]
 __kernel_text_address+0x9a/0x100 kernel/extable.c:105
 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:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261
 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415
 alloc_skb include/linux/skbuff.h:1162 [inline]
 netlink_to_full_skb net/netlink/af_netlink.c:171 [inline]
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:296 [inline]
 __netlink_deliver_tap+0x2f2/0x7c0 net/netlink/af_netlink.c:323
 netlink_deliver_tap+0x16c/0x180 net/netlink/af_netlink.c:336
 netlink_deliver_tap_kernel net/netlink/af_netlink.c:345 [inline]
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x74f/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 sock_write_iter+0x2a6/0x3a0 net/socket.c:1089
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4a9e7f9e59
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:00007f4a9ca32028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4a9ea73090 RCX: 00007f4a9e7f9e59
RDX: 000000000000fe33 RSI: 0000200000000040 RDI: 0000000000000009
RBP: 00007f4a9e88fd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a9ea73128 R14: 00007f4a9ea73090 R15: 00007ffdc7545368
 </TASK>