INFO: rcu detected stall in ip_list_rcv (4)

Status: upstream: reported on 2026/06/29 13:08
Reported-by: syzbot+d048b6277c10563ef2c6@syzkaller.appspotmail.com
First crash: 50d, last: 40d
▶ ▼ Similar bugs (17)
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 1575d 1576d 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 567d 567d 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 704d 760d 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 720d 720d 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 219d 299d 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 10d 988d 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 1132d 1190d 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 2149d 2175d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in ip_list_rcv (4) netfilter 1 1 1507d 1507d 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 2003d 2082d 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 339d 339d 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 1695d 1695d 0/29 closed as invalid on 2022/02/08 10:10
linux-6.6 INFO: rcu detected stall in ip_list_rcv 1 7 46d 258d 0/2 upstream: reported on 2025/12/04 02:09
android-5-15 BUG: soft lockup in ip_list_rcv 1 20 694d 847d 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 746d 768d 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 510d 510d 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 742d 742d 0/2 auto-obsoleted due to no activity on 2024/11/04 20:30

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2644 jiffies s: 3757 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: 4716 Comm: syz.8.40 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
RIP: 0010:rcu_is_watching+0x56/0xa0 kernel/rcu/tree.c:721
Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 a0 24 67 00 48 c7 c3 08 58 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 2f 8b 03 65 ff 0d 35 4c 96 7e 74 0c 83 e0 04 c1 e8 02 5b
RSP: 0018:ffffc90000005c30 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff8880b8e35808 RCX: dd5a3fe03c178e00
RDX: 0000000000000000 RSI: ffffffff8adf42c0 RDI: ffffffff8adf4280
RBP: 0000000000000000 R08: ffffffff8e2121af R09: 1ffffffff1c42435
R10: dffffc0000000000 R11: fffffbfff1c42436 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff8c65f980 R15: dffffc0000000000
FS:  00007f93408746c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 000000007437f000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 trace_local_timer_exit arch/x86/include/asm/trace/irq_vectors.h:41 [inline]
 __sysvec_apic_timer_interrupt+0x1aa/0x5a0 arch/x86/kernel/apic/apic.c:1125
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:unwind_next_frame+0x3bf/0x1fd0 arch/x86/kernel/unwind_orc.c:461
Code: 28 84 c0 0f 85 0d 16 00 00 41 c6 06 01 49 c7 c4 40 8d 89 8a 4d 8d 6c 24 04 4d 8d 74 24 05 4d 89 ef 49 c1 ef 03 41 0f b6 04 2f <84> c0 0f 85 3f 15 00 00 4c 89 f0 48 c1 e8 03 0f b6 04 28 84 c0 0f
RSP: 0018:ffffc90000005d40 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffc90000005de8 RCX: ffffffff8e38067c
RDX: ffffffff8eab68be RSI: ffffffff8e380654 RDI: 0000000000000001
RBP: dffffc0000000000 R08: 000000000000000c R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000000bc9 R12: ffffffff8eab68ee
R13: ffffffff8eab68f2 R14: ffffffff8eab68f3 R15: 1ffffffff1d56d1e
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 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_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 __kmem_cache_free+0xb6/0x200 mm/slub.c:3700
 skb_free_head net/core/skbuff.c:762 [inline]
 skb_release_data+0x5e9/0x7e0 net/core/skbuff.c:791
 skb_release_all net/core/skbuff.c:856 [inline]
 __kfree_skb net/core/skbuff.c:870 [inline]
 consume_skb+0xa2/0x100 net/core/skbuff.c:1035
 __dev_kfree_skb_any+0x12f/0x150 net/core/dev.c:3223
 free_old_xmit_skbs+0x117/0x2b0 drivers/net/virtio_net.c:1639
 start_xmit+0x177/0x1710 drivers/net/virtio_net.c:1901
 __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+0x292/0x8b0 net/core/dev.c:3711
 sch_direct_xmit+0x24d/0x4a0 net/sched/sch_generic.c:345
 __dev_xmit_skb net/core/dev.c:3932 [inline]
 __dev_queue_xmit+0x180d/0x3810 net/core/dev.c:4337
 neigh_output include/net/neighbour.h:545 [inline]
 ip_finish_output2+0xd53/0x1220 net/ipv4/ip_output.c:228
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip_output+0x2d9/0x400 net/ipv4/ip_output.c:434
 dst_output include/net/dst.h:453 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 __ip_queue_xmit+0x10e6/0x1c10 net/ipv4/ip_output.c:538
 __tcp_transmit_skb+0x1cc4/0x31e0 net/ipv4/tcp_output.c:1407
 tcp_ack_snd_check net/ipv4/tcp_input.c:5674 [inline]
 tcp_rcv_established+0xc1e/0x1de0 net/ipv4/tcp_input.c:6118
 tcp_v4_do_rcv+0x67c/0xaf0 net/ipv4/tcp_ipv4.c:1684
 tcp_v4_rcv+0x2810/0x2e90 net/ipv4/tcp_ipv4.c:2115
 ip_protocol_deliver_rcu+0x38c/0x740 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2c0/0x510 net/ipv4/ip_input.c:233
 NF_HOOK+0x329/0x3b0 include/linux/netfilter.h:302
 dst_input include/net/dst.h:463 [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+0xa2e/0xd50 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3e9/0x440 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5662 [inline]
 __netif_receive_skb_list_core+0x57e/0x770 net/core/dev.c:5710
 __netif_receive_skb_list net/core/dev.c:5762 [inline]
 netif_receive_skb_list_internal+0x93f/0xca0 net/core/dev.c:5853
 gro_normal_list include/net/gro.h:433 [inline]
 gro_normal_one include/net/gro.h:446 [inline]
 napi_skb_finish net/core/gro.c:633 [inline]
 napi_gro_receive+0x4eb/0xb50 net/core/gro.c:663
 receive_buf+0x1ac0/0x4e40 drivers/net/virtio_net.c:1327
 virtnet_receive drivers/net/virtio_net.c:1592 [inline]
 virtnet_poll+0x5c9/0x1150 drivers/net/virtio_net.c:1710
 __napi_poll+0xbb/0x460 net/core/dev.c:6628
 napi_poll net/core/dev.c:6695 [inline]
 net_rx_action+0x622/0xbc0 net/core/dev.c:6809
 handle_softirqs+0x291/0x910 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:preempt_schedule_irq+0xb6/0x160 kernel/sched/core.c:6874
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 7f bf 01 00 00 00 e8 b5 cf 1f f7 e8 b0 99 4f f7 fb bf 01 00 00 00 <e8> 25 ba ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc90003a87c40 EFLAGS: 00000286
RAX: dd5a3fe03c178e00 RBX: 0000000000000000 RCX: dd5a3fe03c178e00
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001
RBP: ffffc90003a87ce0 R08: ffffffff90b10347 R09: 1ffffffff2162068
R10: dffffc0000000000 R11: fffffbfff2162069 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000750f88
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__do_sys_perf_event_open kernel/events/core.c:12829 [inline]
RIP: 0010:__se_sys_perf_event_open+0x1ad0/0x1ec0 kernel/events/core.c:12418
Code: 8b 5c 24 30 48 89 df e8 ce 3a 00 00 48 89 df e8 f6 43 00 00 49 8d 7d 48 e8 7d a5 93 08 4c 89 ef e8 75 a0 fe ff 48 8b 7c 24 30 <48> 83 c7 48 e8 67 a5 93 08 80 7c 24 24 00 74 07 e8 7b 8b dc ff eb
RSP: 0018:ffffc90003a87da0 EFLAGS: 00000246
RAX: dd5a3fe03c178e00 RBX: ffff88802fedf800 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffff88802fedf800
RBP: ffffc90003a87f10 R08: ffffffff90b10347 R09: 1ffffffff2162068
R10: dffffc0000000000 R11: fffffbfff2162069 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88813fef0000 R15: 1ffff92000750fc0
 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: 0033:0x7f933f99de59
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:00007f9340874028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f933fc25fa0 RCX: 00007f933f99de59
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 00002000000012c0
RBP: 00007f933fa33e6f R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f933fc26038 R14: 00007f933fc25fa0 R15: 00007ffff7ad9e78
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/10 03:07 linux-6.1.y 090666d3cc90 4167ee25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/07/06 03:19 linux-6.1.y 090666d3cc90 fcece630 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/07/05 11:47 linux-6.1.y 090666d3cc90 fcece630 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/07/03 15:24 linux-6.1.y fdb6fcb41cc7 58bf2096 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/06/29 13:07 linux-6.1.y fdb6fcb41cc7 6a0c72dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in ip_list_rcv
* Struck through repros no longer work on HEAD.