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: 52d, last: 4d21h
▶ ▼ 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 1661d 1662d 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 653d 653d 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 790d 845d 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 806d 806d 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 305d 384d 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 21d 1074d 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 1218d 1276d 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 2235d 2261d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in ip_list_rcv (4) netfilter 1 1 1593d 1593d 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 2089d 2168d 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 425d 425d 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 1781d 1781d 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 74d 136d 0/3 upstream: reported on 2026/06/29 13:08
linux-6.6 INFO: rcu detected stall in ip_list_rcv 1 10 4d04h 343d 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 39d 39d 0/2 upstream: reported C repro on 2026/10/04 02:09
android-5-15 BUG: soft lockup in ip_list_rcv 1 20 779d 933d 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 832d 854d 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 596d 596d 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 828d 828d 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=57f/1/0x4000000000000000 softirq=32881/32882 fqs=4274 
	(t=10500 jiffies g=47901 q=3417)
NMI backtrace for cpu 0
CPU: 0 PID: 14175 Comm: syz.2.2222 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
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:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:408
Code: 8a e8 a6 61 80 08 65 66 8b 05 ae 5d ba 7e 66 85 c0 75 54 bf 01 00 00 00 e8 8f 23 09 00 e8 0a 1e 36 00 fb 65 8b 05 5a 34 b9 7e <85> c0 75 05 e8 99 41 b7 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc900000067c0 EFLAGS: 00000282
RAX: 0000000000000302 RBX: 0000000000000200 RCX: 1c5b3c8c32d5d100
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a5100
RBP: ffffc90000006848 R08: ffffffff91047197 R09: 1ffffffff2208e32
R10: dffffc0000000000 R11: fffffbfff2208e33 R12: ffffffff87f29cf5
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000000cf8
 __neigh_event_send+0x84/0x1410 net/core/neighbour.c:1181
 neigh_event_send include/net/neighbour.h:438 [inline]
 neigh_resolve_output+0x1ab/0x6a0 net/core/neighbour.c:1488
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0xcdd/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_rcv_established+0x13db/0x1de0 net/ipv4/tcp_input.c:6040
 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: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]
 gro_normal_one net/core/dev.c:5953 [inline]
 napi_skb_finish net/core/dev.c:6290 [inline]
 napi_gro_receive+0x4eb/0xa60 net/core/dev.c:6320
 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: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
 __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:preempt_schedule_irq+0xb6/0x160 kernel/sched/core.c:6799
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 55 82 80 f7 e8 60 7e ad f7 fb bf 01 00 00 00 <e8> d5 b5 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc9000331dd60 EFLAGS: 00000286
RAX: 1c5b3c8c32d5d100 RBX: 0000000000000000 RCX: 1c5b3c8c32d5d100
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: 0000000000000001
RBP: ffffc9000331de10 R08: ffffffff91047177 R09: 1ffffffff2208e2e
R10: dffffc0000000000 R11: fffffbfff2208e2f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000663bac
 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:put_cpu_partial+0x15e/0x190 mm/slub.c:2591
Code: 00 00 48 3b 44 24 08 75 4d 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 7f 82 0b 08 41 f7 c5 00 02 00 00 74 c3 fb 4d 85 ff <75> c2 eb cb 48 c7 c7 90 24 1f 8d 4c 89 e6 e8 6f 8f 4b 02 e9 e5 fe
RSP: 0018:ffffc9000331ded8 EFLAGS: 00000246
RAX: 1c5b3c8c32d5d100 RBX: ffff8880179df8c0 RCX: 1c5b3c8c32d5d100
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a5100
RBP: 0000000000000001 R08: ffffffff91047177 R09: 1ffffffff2208e2e
R10: dffffc0000000000 R11: fffffbfff2208e2f R12: 0000000000000000
R13: 0000000000000286 R14: ffff8880b8e415e0 R15: 0000000000000000
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
 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]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238
 zswap_entry_cache_alloc mm/zswap.c:278 [inline]
 zswap_frontswap_store+0x403/0x1530 mm/zswap.c:1130
 __frontswap_store+0x331/0x4a0 mm/frontswap.c:276
 frontswap_store include/linux/frontswap.h:90 [inline]
 swap_writepage+0x5f/0xa0 mm/page_io.c:197
 shmem_writepage+0x106c/0x13b0 mm/shmem.c:1448
 pageout mm/vmscan.c:1082 [inline]
 shrink_page_list+0x43a8/0x6de0 mm/vmscan.c:1669
 shrink_inactive_list mm/vmscan.c:2223 [inline]
 shrink_list mm/vmscan.c:2450 [inline]
 shrink_lruvec+0x1315/0x25a0 mm/vmscan.c:2769
 shrink_node_memcgs mm/vmscan.c:2956 [inline]
 shrink_node+0x1190/0x2790 mm/vmscan.c:3079
 shrink_zones mm/vmscan.c:3285 [inline]
 do_try_to_free_pages+0x60e/0x1600 mm/vmscan.c:3340
 try_to_free_mem_cgroup_pages+0x347/0x800 mm/vmscan.c:3654
 try_charge_memcg+0x42f/0x15b0 mm/memcontrol.c:2654
 obj_cgroup_charge_pages+0x87/0x190 mm/memcontrol.c:3018
 __memcg_kmem_charge_page+0x2fe/0x380 mm/memcontrol.c:3058
 __alloc_pages+0x222/0x480 mm/page_alloc.c:5518
 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline]
 pte_alloc_one+0x7b/0x310 arch/x86/mm/pgtable.c:33
 __pte_alloc+0x21/0x150 mm/memory.c:439
 copy_pte_range mm/memory.c:1032 [inline]
 copy_pmd_range mm/memory.c:1167 [inline]
 copy_pud_range mm/memory.c:1204 [inline]
 copy_p4d_range mm/memory.c:1228 [inline]
 copy_page_range+0x2ab2/0x32c0 mm/memory.c:1301
 dup_mmap kernel/fork.c:616 [inline]
 dup_mm kernel/fork.c:1475 [inline]
 copy_mm+0xc61/0x13d0 kernel/fork.c:1527
 copy_process+0x19da/0x4250 kernel/fork.c:2307
 kernel_clone+0x23f/0x990 kernel/fork.c:2699
 __do_sys_clone kernel/fork.c:2816 [inline]
 __se_sys_clone kernel/fork.c:2800 [inline]
 __x64_sys_clone+0x19a/0x210 kernel/fork.c:2800
 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: 0033:0x7f1220782b19
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:00007f121e9d8fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f1220a08fa0 RCX: 00007f1220782b19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000800000
RBP: 00007f122081ab70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f1220a09038 R14: 00007f1220a08fa0 R15: 00007ffda7e65c38
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/08 00:25 linux-5.15.y 29c6cdaac04a 5cecaf1f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in ip_list_rcv
2026/11/05 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.