INFO: rcu detected stall in ip_list_rcv

Status: upstream: reported on 2025/12/04 02:09
Reported-by: syzbot+70204a71afdd800448da@syzkaller.appspotmail.com
First crash: 264d, last: 4d05h
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 1581d 1582d 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 573d 573d 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 710d 765d 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 726d 726d 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 225d 305d 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 61 16d 994d 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 1138d 1196d 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 2155d 2181d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in ip_list_rcv (4) netfilter 1 1 1513d 1513d 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 2009d 2088d 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 345d 345d 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 1701d 1701d 0/29 closed as invalid on 2022/02/08 10:10
linux-6.1 INFO: rcu detected stall in ip_list_rcv (4) 1 5 45d 56d 0/3 upstream: reported on 2026/06/29 13:08
android-5-15 BUG: soft lockup in ip_list_rcv 1 20 700d 853d 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 752d 774d 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 516d 516d 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 748d 748d 0/2 auto-obsoleted due to no activity on 2024/11/04 20:30
upstream BUG: soft lockup in ip_list_rcv net 1 1 2082d 2082d 0/29 auto-closed as invalid on 2021/03/11 09:36

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 13262 jiffies s: 184953 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 27330 Comm: syz.1.6159 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:pagefault_disabled_inc include/linux/uaccess.h:210 [inline]
RIP: 0010:pagefault_disable include/linux/uaccess.h:227 [inline]
RIP: 0010:perf_callchain_user+0x23b/0x15d0 arch/x86/events/core.c:2939
Code: e8 0a 40 86 00 41 83 fd 33 0f 85 30 01 00 00 65 4c 8b 2d a8 82 02 7f 49 8d 9d 8c 17 00 00 49 89 de 49 c1 ee 03 43 0f b6 04 3e <84> c0 0f 85 af 0f 00 00 4c 89 74 24 20 48 89 5c 24 28 41 ff 85 8c
RSP: 0018:ffffc90000005ee8 EFLAGS: 00000803
RAX: 0000000000000000 RBX: ffff888029cb718c RCX: 0000000000000100
RDX: ffff888029cb5a00 RSI: 0000000000000033 RDI: 0000000000000033
RBP: 00007f1b58835024 R08: ffffffff8e8c7e2f R09: 1ffffffff1d18fc5
R10: dffffc0000000000 R11: fffffbfff1d18fc6 R12: ffffc90004a3ff58
R13: ffff888029cb5a00 R14: 1ffff11005396e31 R15: dffffc0000000000
FS:  00007f1b597256c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000006b5ed000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 get_perf_callchain+0x394/0x510 kernel/events/callchain.c:219
 perf_callchain kernel/events/core.c:7734 [inline]
 perf_sample_save_callchain include/linux/perf_event.h:1232 [inline]
 perf_prepare_sample+0x3c7/0x1db0 kernel/events/core.c:7778
 __perf_event_output kernel/events/core.c:7966 [inline]
 perf_event_output_forward+0x187/0x3e0 kernel/events/core.c:7987
 __perf_event_overflow+0x461/0x660 kernel/events/core.c:9712
 perf_swevent_overflow kernel/events/core.c:9795 [inline]
 perf_swevent_event+0x319/0x570 kernel/events/core.c:9846
 perf_tp_event+0x620/0x1550 kernel/events/core.c:10373
 perf_trace_run_bpf_submit+0xf4/0x1c0 kernel/events/core.c:10292
 perf_trace_preemptirq_template+0x269/0x330 include/trace/events/preemptirq.h:14
 trace_irq_enable+0xbb/0xe0 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:arch_atomic_add_negative arch/x86/include/asm/atomic.h:79 [inline]
RIP: 0010:raw_atomic_add_negative_relaxed include/linux/atomic/atomic-arch-fallback.h:2380 [inline]
RIP: 0010:atomic_add_negative_relaxed include/linux/atomic/atomic-instrumented.h:1468 [inline]
RIP: 0010:rcuref_get include/linux/rcuref.h:67 [inline]
RIP: 0010:dst_hold_safe include/net/dst.h:309 [inline]
RIP: 0010:skb_dst_force include/net/dst.h:325 [inline]
RIP: 0010:__neigh_event_send+0xc60/0x1480 net/core/neighbour.c:1239
Code: 46 53 00 f9 85 ed 0f 84 07 03 00 00 e8 89 4f 00 f9 4d 8d 7d 40 4c 89 ff be 04 00 00 00 e8 48 ca 58 f9 31 f6 f0 41 83 45 40 01 <40> 0f 98 c5 40 0f 98 c6 bf 02 00 00 00 e8 ee 51 00 f9 40 84 ed 0f
RSP: 0018:ffffc90000006850 EFLAGS: 00000206
RAX: ffffffff88872201 RBX: ffff88807c2cf010 RCX: ffffffff888722f8
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88801c241240
RBP: 0000000000000001 R08: ffff88801c241243 R09: 1ffff11003848248
R10: dffffc0000000000 R11: ffffed1003848249 R12: ffff88823bd26058
R13: ffff88801c241200 R14: 1ffff110477a4c0b R15: ffff88801c241240
 neigh_event_send_probe include/net/neighbour.h:467 [inline]
 neigh_event_send include/net/neighbour.h:473 [inline]
 neigh_resolve_output+0x1a4/0x710 net/core/neighbour.c:1552
 neigh_output include/net/neighbour.h:547 [inline]
 ip_finish_output2+0xd97/0x1260 net/ipv4/ip_output.c:235
 NF_HOOK_COND include/linux/netfilter.h:293 [inline]
 ip_output+0x2a5/0x3a0 net/ipv4/ip_output.c:436
 dst_output include/net/dst.h:467 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x1056/0x1960 net/ipv4/ip_output.c:540
 __tcp_transmit_skb+0x1dd6/0x3470 net/ipv4/tcp_output.c:1427
 tcp_validate_incoming+0xf37/0x22b0 net/ipv4/tcp_input.c:5901
 tcp_rcv_established+0x7e1/0x1d70 net/ipv4/tcp_input.c:6166
 tcp_v4_do_rcv+0x6d3/0xba0 net/ipv4/tcp_ipv4.c:1737
 tcp_v4_rcv+0x2358/0x2a60 net/ipv4/tcp_ipv4.c:2169
 ip_protocol_deliver_rcu+0x20a/0x3f0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2c3/0x510 net/ipv4/ip_input.c:233
 NF_HOOK+0x32d/0x3b0 include/linux/netfilter.h:304
 dst_input include/net/dst.h:477 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0xa36/0xd60 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3ed/0x440 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5702 [inline]
 __netif_receive_skb_list_core+0x2d9/0x770 net/core/dev.c:5740
 __netif_receive_skb_list net/core/dev.c:5802 [inline]
 netif_receive_skb_list_internal+0x943/0xca0 net/core/dev.c:5893
 gro_normal_list include/net/gro.h:451 [inline]
 gro_normal_one include/net/gro.h:464 [inline]
 napi_skb_finish net/core/gro.c:580 [inline]
 napi_gro_receive+0x553/0xaf0 net/core/gro.c:610
 receive_buf+0x20ab/0x3660 drivers/net/virtio_net.c:1874
 virtnet_receive drivers/net/virtio_net.c:2159 [inline]
 virtnet_poll+0x69e/0x1300 drivers/net/virtio_net.c:2236
 __napi_poll+0xbb/0x460 net/core/dev.c:6663
 napi_poll net/core/dev.c:6730 [inline]
 net_rx_action+0x65f/0xcc0 net/core/dev.c:6866
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:generic_exec_single+0x477/0x4e0 kernel/smp.c:418
Code: 75 11 e8 0c 10 0b 00 48 85 db 75 16 e8 02 10 0b 00 eb 15 e8 fb 0f 0b 00 e8 06 f8 12 09 48 85 db 74 ea e8 ec 0f 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08
RSP: 0018:ffffc90004a3fa00 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc90015ab4000 RSI: 0000000000003eaa RDI: 0000000000003eab
RBP: ffffc90004a3fad0 R08: ffffffff911ee5ff R09: 1ffffffff223dcbf
R10: dffffc0000000000 R11: fffffbfff223dcc0 R12: 1ffff92000947f44
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92000947f65
 smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647
 task_function_call kernel/events/core.c:120 [inline]
 perf_install_in_context+0x5bb/0x920 kernel/events/core.c:2950
 __do_sys_perf_event_open kernel/events/core.c:12949 [inline]
 __se_sys_perf_event_open+0x1841/0x1c60 kernel/events/core.c:12601
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1b5879e0d9
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:00007f1b59725028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f1b58a25fa0 RCX: 00007f1b5879e0d9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000680
RBP: 00007f1b58835024 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1b58a26038 R14: 00007f1b58a25fa0 R15: 00007ffe5394a668
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/20 21:21 linux-6.6.y c610b395b0a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/07/03 07:21 linux-6.6.y d1cfde2d5d15 58bf2096 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in ip_list_rcv
2026/05/27 04:25 linux-6.6.y 0a40c6fbd105 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/05/12 04:43 linux-6.6.y 3b9f64db0496 d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/04/28 19:05 linux-6.6.y 142cd8382222 ce741359 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/02/15 10:26 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in ip_list_rcv
2025/12/04 02:08 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/04/18 00:37 linux-6.6.y 8cee53b8eaeb 24ecfc1e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf BUG: soft lockup in ip_list_rcv
* Struck through repros no longer work on HEAD.