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: 4h16m, last: 4h16m
▶ ▼ Similar bugs (18)
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 1609d 1609d 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 601d 601d 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 738d 793d 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 754d 754d 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 253d 332d 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 62 11d 1022d 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 1165d 1224d 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 2183d 2209d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in ip_list_rcv (4) netfilter 1 1 1541d 1541d 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 2037d 2116d 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 373d 373d 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 1729d 1729d 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 22d 84d 0/3 upstream: reported on 2026/06/29 13:08
linux-6.6 INFO: rcu detected stall in ip_list_rcv 1 8 31d 291d 0/2 upstream: reported on 2025/12/04 02:09
android-5-15 BUG: soft lockup in ip_list_rcv 1 20 727d 881d 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 780d 802d 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 544d 544d 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 775d 775d 0/2 auto-obsoleted due to no activity on 2024/11/04 20:30

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=2c1/1/0x4000000000000000 softirq=6683/6684 fqs=3199 
	(t=10500 jiffies g=7905 q=2715)
NMI backtrace for cpu 0
CPU: 0 PID: 4399 Comm: syz.1.34 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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_dump_cpu_stacks+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ec/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+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:get_current mm/page_alloc.c:4589 [inline]
RIP: 0010:current_gfp_context include/linux/sched/mm.h:166 [inline]
RIP: 0010:fs_reclaim_acquire+0x0/0x100 mm/page_alloc.c:4590
Code: 45 31 c9 50 e8 b1 a4 a8 ff 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 fe 48 c7 c7 80 ed 3d 8c e9 21 25 a9 ff 90 <55> 53 65 48 8b 1d e6 27 4e 7e 48 83 c3 2c 48 89 d8 48 c1 e8 03 48
RSP: 0018:ffffc900000062c0 EFLAGS: 00000202
RAX: ab4724ef746a2900 RBX: ffff888144bf0140 RCX: 0000000000000a20
RDX: 0000000000000001 RSI: ffffc900000062f8 RDI: 0000000000000a20
RBP: 0000000000000a20 R08: dffffc0000000000 R09: 1ffffffff203e218
R10: dffffc0000000000 R11: fffffbfff203e219 R12: dffffc0000000000
R13: 0000000000000a20 R14: ffffc900000062f8 R15: 0000000000000001
 might_alloc include/linux/sched/mm.h:206 [inline]
 slab_pre_alloc_hook+0x20/0xc0 mm/slab.h:492
 slab_alloc_node mm/slub.c:3139 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x3d/0x280 mm/slub.c:3238
 skb_clone+0x1bd/0x350 net/core/skbuff.c:1527
 dev_queue_xmit_nit+0x2db/0xae0 net/core/dev.c:2354
 xmit_one net/core/dev.c:3657 [inline]
 dev_hard_start_xmit+0x140/0x7d0 net/core/dev.c:3678
 sch_direct_xmit+0x24d/0x4a0 net/sched/sch_generic.c:345
 __dev_xmit_skb net/core/dev.c:3897 [inline]
 __dev_queue_xmit+0x1694/0x2e50 net/core/dev.c:4266
 neigh_hh_output include/net/neighbour.h:493 [inline]
 neigh_output include/net/neighbour.h:507 [inline]
 ip_finish_output2+0xc77/0x10e0 net/ipv4/ip_output.c:228
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip_output+0x2ba/0x3e0 net/ipv4/ip_output.c:434
 dst_output include/net/dst.h:452 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 __ip_queue_xmit+0x11fc/0x1c60 net/ipv4/ip_output.c:538
 __tcp_transmit_skb+0x1ca3/0x31e0 net/ipv4/tcp_output.c:1404
 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline]
 tcp_write_xmit+0x1a8d/0x65c0 net/ipv4/tcp_output.c:2718
 __tcp_push_pending_frames+0x92/0x250 net/ipv4/tcp_output.c:2903
 tcp_push_pending_frames include/net/tcp.h:1918 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5572 [inline]
 tcp_rcv_established+0xf1e/0x1d00 net/ipv4/tcp_input.c:5983
 tcp_v4_do_rcv+0x435/0x9b0 net/ipv4/tcp_ipv4.c:1738
 tcp_v4_rcv+0x276f/0x2da0 net/ipv4/tcp_ipv4.c:2150
 ip_protocol_deliver_rcu+0x38c/0x740 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x1d8/0x320 net/ipv4/ip_input.c:231
 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302
 dst_input include/net/dst.h:462 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:577 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline]
 ip_sublist_rcv+0xa1b/0xd10 net/ipv4/ip_input.c:636
 ip_list_rcv+0x3e9/0x440 net/ipv4/ip_input.c:671
 __netif_receive_skb_list_ptype net/core/dev.c:5594 [inline]
 __netif_receive_skb_list_core+0x57e/0x770 net/core/dev.c:5642
 __netif_receive_skb_list net/core/dev.c:5694 [inline]
 netif_receive_skb_list_internal+0x898/0xbd0 net/core/dev.c:5785
 gro_normal_list net/core/dev.c:5939 [inline]
 gro_normal_one net/core/dev.c:5952 [inline]
 napi_skb_finish net/core/dev.c:6289 [inline]
 napi_gro_receive+0x4eb/0xa60 net/core/dev.c:6319
 receive_buf+0x39de/0x59d0 drivers/net/virtio_net.c:1240
 virtnet_receive drivers/net/virtio_net.c:1504 [inline]
 virtnet_poll+0x5ce/0xfb0 drivers/net/virtio_net.c:1620
 __napi_poll+0xbb/0x430 net/core/dev.c:7101
 napi_poll net/core/dev.c:7168 [inline]
 net_rx_action+0x522/0xa80 net/core/dev.c:7258
 handle_softirqs+0x336/0x830 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+0x12f/0x290 kernel/sched/core.c:4804
Code: 83 c7 18 be ff ff ff ff e8 8e da 6c 08 85 c0 74 46 4d 85 ff 75 62 0f 1f 44 00 00 48 89 df e8 78 4a 76 08 e8 93 e3 2a 00 fb 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 2f 0e fe ff 43 80 3c 2c
RSP: 0018:ffffc9000326f718 EFLAGS: 00000282
RAX: ab4724ef746a2900 RBX: ffff8880264c8000 RCX: ab4724ef746a2900
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a48c0
RBP: 1ffff11017207613 R08: ffffffff901f11cf R09: 1ffffffff203e239
R10: dffffc0000000000 R11: fffffbfff203e23a R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
 finish_task_switch+0x12f/0x650 kernel/sched/core.c:4921
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11cb/0x4350 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:435
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:preempt_schedule+0x0/0xd0 kernel/sched/core.c:6588
Code: f7 eb a2 0f 1f 80 00 00 00 00 bf 01 00 00 00 e8 f6 dc 88 f7 e8 81 fd ff ff bf 01 00 00 00 e8 57 db 88 f7 c3 66 0f 1f 44 00 00 <55> 48 89 e5 41 56 53 48 83 e4 e0 48 83 ec 60 65 48 8b 04 25 28 00
RSP: 0018:ffffc9000326fae0 EFLAGS: 00000283
RAX: ffffffff816d8db6 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000594a000 RSI: 0000000000000e25 RDI: 0000000000000e26
RBP: ffffc9000326fb30 R08: ffffffff901f11cf R09: 1ffffffff203e239
R10: dffffc0000000000 R11: fffffbfff203e23a R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: 1ffff9200064df6c
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 smp_call_function_single+0x42b/0x4c0 kernel/smp.c:760
 task_function_call kernel/events/core.c:120 [inline]
 perf_install_in_context+0x5cf/0x930 kernel/events/core.c:3026
 __do_sys_perf_event_open kernel/events/core.c:12803 [inline]
 __se_sys_perf_event_open+0x12b3/0x1bb0 kernel/events/core.c:12397
 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: 0033:0x7f0c18b1e159
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:00007f0c16d76028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f0c18da5fa0 RCX: 00007f0c18b1e159
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000300
RBP: 00007f0c18bb506b R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c18da6038 R14: 00007f0c18da5fa0 R15: 00007ffe6818b4e8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.