INFO: rcu detected stall in ip_list_rcv (3)

Status: upstream: reported on 2026/09/21 15:44
Reported-by: syzbot+eec30beefe223cba3b0a@syzkaller.appspotmail.com
First crash: 47d, last: 1d17h
▶ ▼ Similar bugs (19)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: soft lockup in ip_list_rcv (2) kvm 1 8 1656d 1656d 0/29 auto-closed as invalid on 2022/06/25 08:42
linux-6.1 INFO: rcu detected stall in ip_list_rcv (2) 1 1 648d 648d 0/3 auto-obsoleted due to no activity on 2025/05/08 11:17
linux-5.15 INFO: rcu detected stall in ip_list_rcv 1 2 784d 840d 0/3 auto-obsoleted due to no activity on 2024/12/22 19:35
linux-6.1 INFO: rcu detected stall in ip_list_rcv 1 1 800d 800d 0/3 auto-obsoleted due to no activity on 2024/12/06 18:02
linux-5.15 INFO: rcu detected stall in ip_list_rcv (2) 1 2 300d 379d 0/3 auto-obsoleted due to no activity on 2026/04/21 10:23
upstream INFO: rcu detected stall in ip_list_rcv (6) prio:low net 1 syz, C done done 63 16d 1069d 0/29 upstream: reported C repro on 2023/12/04 09:45
upstream INFO: rcu detected stall in ip_list_rcv (5) lsm netfilter 1 3 1212d 1271d 0/29 auto-obsoleted due to no activity on 2023/10/11 22:12
upstream INFO: rcu detected stall in ip_list_rcv net 1 syz, C error done 3 2229d 2256d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in ip_list_rcv (4) netfilter 1 1 1588d 1588d 0/29 auto-closed as invalid on 2022/09/01 16:20
upstream INFO: rcu detected stall in ip_list_rcv (2) netfilter 1 3 2084d 2163d 0/29 auto-closed as invalid on 2021/05/23 12:59
linux-6.1 INFO: rcu detected stall in ip_list_rcv (3) 1 1 420d 420d 0/3 auto-obsoleted due to no activity on 2025/12/22 08:55
upstream INFO: rcu detected stall in ip_list_rcv (3) net 1 1 1776d 1776d 0/29 closed as invalid on 2022/02/08 10:10
linux-6.1 INFO: rcu detected stall in ip_list_rcv (4) 1 6 69d 131d 0/3 upstream: reported on 2026/06/29 13:08
linux-6.6 INFO: rcu detected stall in ip_list_rcv 1 9 24d 338d 0/2 upstream: reported on 2025/12/04 02:09
android-5-15 BUG: soft lockup in ip_list_rcv (3) 1 syz, C 1 34d 34d 0/2 upstream: reported C repro on 2026/10/04 02:09
android-5-15 BUG: soft lockup in ip_list_rcv 1 20 774d 928d 0/2 auto-obsoleted due to no activity on 2024/12/22 22:06
android-6-1 BUG: soft lockup in ip_list_rcv 1 2 826d 849d 0/2 auto-obsoleted due to no activity on 2024/10/31 19:10
android-5-15 BUG: soft lockup in ip_list_rcv (2) 1 1 591d 591d 0/2 auto-obsoleted due to no activity on 2025/06/24 13:43
android-5-10 BUG: soft lockup in ip_list_rcv 1 1 822d 822d 0/2 auto-obsoleted due to no activity on 2024/11/04 20:30

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=aef/1/0x4000000000000000 softirq=35818/35819 fqs=5 
	(detected by 1, t=10502 jiffies, g=56449, q=212)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:192 [inline]
RIP: 0010:mark_lock+0x56/0x320 kernel/locking/lockdep.c:4642
Code: 03 42 0f b6 04 28 84 c0 0f 85 74 02 00 00 41 0f b6 47 02 24 03 3c 01 bd 09 00 00 00 83 dd 00 41 bc 01 00 00 00 89 e9 41 d3 e4 <4d> 8d 7e 20 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 22 02
RSP: 0018:ffffc900000078e0 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff88813fea9dc0 RCX: 0000000000000004
RDX: 0000000000000004 RSI: ffff88813feaa928 RDI: ffff88813fea9dc0
RBP: 0000000000000004 R08: dffffc0000000000 R09: 1ffffffff2208e62
R10: dffffc0000000000 R11: fffffbfff2208e63 R12: 0000000000000010
R13: dffffc0000000000 R14: ffff88813feaa928 R15: ffff88813feaa948
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555558d444e8 CR3: 00000000205c6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 mark_usage kernel/locking/lockdep.c:-1 [inline]
 __lock_acquire+0xd77/0x7d40 kernel/locking/lockdep.c:5074
 lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:364 [inline]
 advance_sched+0x49/0x920 net/sched/sch_taprio.c:691
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4ea/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 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+0x9b/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:vprintk_store+0xf13/0x11b0 kernel/printk/printk.c:2237
Code: e8 a2 fd 18 00 fb 45 31 ff eb 15 e8 97 fd 18 00 e8 62 5b 69 08 4d 85 e4 74 ab e8 88 fd 18 00 fb 48 b8 00 00 00 00 00 fc ff df <66> 41 c7 44 06 24 f8 f8 41 c6 44 06 26 f8 41 c6 44 06 20 f8 66 41
RSP: 0018:ffffc90000d368c0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88813fea9dc0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000d36ad0 R08: ffffffff91047197 R09: 1ffffffff2208e32
R10: dffffc0000000000 R11: fffffbfff2208e33 R12: 0000000000000200
R13: 0000000000000000 R14: 1ffff920001a6d24 R15: 000000000000008c
 vprintk_emit+0x85/0x150 kernel/printk/printk.c:2258
 _printk+0xda/0x130 kernel/printk/printk.c:2299
 __dynamic_pr_debug+0x196/0x240 lib/dynamic_debug.c:619
 tcp_in_window net/netfilter/nf_conntrack_proto_tcp.c:590 [inline]
 nf_conntrack_tcp_packet+0x5947/0x60a0 net/netfilter/nf_conntrack_proto_tcp.c:1195
 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1900 [inline]
 nf_conntrack_in+0xbd6/0x17b0 net/netfilter/nf_conntrack_core.c:1991
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_slow net/netfilter/core.c:584 [inline]
 nf_hook_slow_list+0x272/0x5b0 net/netfilter/core.c:623
 NF_HOOK_LIST include/linux/netfilter.h:338 [inline]
 ip_sublist_rcv+0xc01/0xd10 net/ipv4/ip_input.c:634
 ip_list_rcv+0x3e9/0x440 net/ipv4/ip_input.c:671
 __netif_receive_skb_list_ptype net/core/dev.c:5595 [inline]
 __netif_receive_skb_list_core+0x57e/0x770 net/core/dev.c:5643
 __netif_receive_skb_list net/core/dev.c:5695 [inline]
 netif_receive_skb_list_internal+0x898/0xbd0 net/core/dev.c:5786
 gro_normal_list net/core/dev.c:5940 [inline]
 napi_complete_done+0x37e/0x850 net/core/dev.c:6678
 virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline]
 virtnet_poll+0x9b7/0xfb0 drivers/net/virtio_net.c:1627
 __napi_poll+0xbb/0x430 net/core/dev.c:7102
 napi_poll net/core/dev.c:7169 [inline]
 net_rx_action+0x522/0xa80 net/core/dev.c:7259
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943
 smpboot_thread_fn+0x520/0x990 kernel/smpboot.c:164
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10492 jiffies! g56449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27408 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 21 Comm: kworker/1:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: events bpf_prog_free_deferred
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x845/0x1120 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+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 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+0x9b/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:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xba3/0xd80 kernel/smp.c:969
Code: 0f b6 44 05 00 84 c0 0f 85 9a 00 00 00 41 8b 1e 89 de 83 e6 01 31 ff e8 eb 79 0b 00 83 e3 01 75 07 e8 81 76 0b 00 eb 42 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 10 41 f7
RSP: 0018:ffffc90000db7860 EFLAGS: 00000293
RAX: ffffffff816db735 RBX: 0000000000000001 RCX: ffff88813fe69dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000db79a0 R08: ffffffff910470cf R09: 1ffffffff2208e19
R10: dffffc0000000000 R11: fffffbfff2208e1a R12: ffff8880b8f3b3c0
R13: 1ffff110171c8509 R14: ffff8880b8e42848 R15: 0000000000000000
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1134
 __purge_vmap_area_lazy+0x21e/0x1940 mm/vmalloc.c:1723
 _vm_unmap_aliases+0x40b/0x4a0 mm/vmalloc.c:2147
 vm_remove_mappings mm/vmalloc.c:2624 [inline]
 __vunmap+0x72f/0xa80 mm/vmalloc.c:2651
 bpf_jit_binary_free kernel/bpf/core.c:918 [inline]
 bpf_jit_free+0x92/0x180 kernel/bpf/core.c:931
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/05 23:01 linux-5.15.y 700e62ea909a 5cecaf1f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in ip_list_rcv
2026/10/22 00:12 linux-5.15.y 792fbe1537d8 4ba27f85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/10/03 18:15 linux-5.15.y a051a4bf909f 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/09/21 15:43 linux-5.15.y 0248c33e835e 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in ip_list_rcv
* Struck through repros no longer work on HEAD.