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: 16d, last: 4d07h
▶ ▼ 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 1625d 1626d 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 617d 617d 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 754d 809d 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 770d 770d 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 269d 349d 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 27d 1038d 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 1182d 1240d 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 2199d 2225d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in ip_list_rcv (4) netfilter 1 1 1557d 1557d 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 2053d 2132d 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 389d 389d 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 1745d 1745d 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 38d 100d 0/3 upstream: reported on 2026/06/29 13:08
linux-6.6 INFO: rcu detected stall in ip_list_rcv 1 8 48d 308d 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 4d00h 4d00h 0/2 upstream: reported C repro on 2026/10/04 02:09
android-5-15 BUG: soft lockup in ip_list_rcv 1 20 744d 897d 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 796d 818d 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 560d 560d 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 792d 792d 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: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P25481
	(detected by 0, t=10502 jiffies, g=108637, q=972)
task:syz.7.6215      state:R  running task     stack:24272 pid:25481 ppid: 24689 flags:0x0000400c
Call Trace:
 <IRQ>
 sched_show_task+0x459/0x580 kernel/sched/core.c:8659
 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:233 [inline]
 print_other_cpu_stall+0xec5/0x1270 kernel/rcu/tree_stall.h:573
 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+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:__lt_find include/linux/rbtree_latch.h:113 [inline]
RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:208 [inline]
RIP: 0010:bpf_ksym_find kernel/bpf/core.c:692 [inline]
RIP: 0010:is_bpf_text_address+0x17f/0x270 kernel/bpf/core.c:726
Code: 39 df 73 47 e8 12 d0 f3 ff b8 08 00 00 00 49 01 c6 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 04 15 39 00 4d 8b 36 <4d> 85 f6 74 0a e8 e7 cf f3 ff e9 5a ff ff ff e8 dd cf f3 ff 31 ed
RSP: 0018:ffffc90000006700 EFLAGS: 00000246
RAX: 1ffffffff1a89f9c RBX: 00007fdbc7f98159 RCX: ffff888025bc0000
RDX: 0000000000000100 RSI: 00007fdbc7f98159 RDI: ffffffffa002e000
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff2042818
R10: dffffc0000000000 R11: fffffbfff2042819 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffffa002e000
 kernel_text_address kernel/extable.c:151 [inline]
 __kernel_text_address+0x9a/0x100 kernel/extable.c:105
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb_fclone include/linux/skbuff.h:1212 [inline]
 sk_stream_alloc_skb+0x204/0xb50 net/ipv4/tcp.c:892
 tso_fragment net/ipv4/tcp_output.c:2131 [inline]
 tcp_write_xmit+0x111e/0x65c0 net/ipv4/tcp_output.c:2704
 __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+0xff2/0x1de0 net/ipv4/tcp_input.c:5984
 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+0x2d5/0x770 net/core/dev.c:5632
 __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
 common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
 </IRQ>
 <TASK>
 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
RIP: 0010:lock_acquire+0x209/0x400 kernel/locking/lockdep.c:5741
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000357f240 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 65685d14e588fd00
RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4b80
RBP: ffffc9000357f360 R08: dffffc0000000000 R09: 1ffffffff2042818
R10: dffffc0000000000 R11: fffffbfff2042819 R12: 1ffff920006afe54
R13: ffffffff8c31efa0 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725
 kernel_text_address kernel/extable.c:151 [inline]
 __kernel_text_address+0x9a/0x100 kernel/extable.c:105
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x92/0xc0 mm/kasan/common.c:467
 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
 skb_clone+0x1bd/0x350 net/core/skbuff.c:1527
 ____bpf_clone_redirect net/core/filter.c:2456 [inline]
 bpf_clone_redirect+0x166/0x460 net/core/filter.c:2434
 bpf_prog_6893982b85ceadf7+0x56/0x6c8
 bpf_dispatcher_nop_func include/linux/bpf.h:890 [inline]
 __bpf_prog_run include/linux/filter.h:621 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 bpf_test_run+0x4ae/0x800 net/bpf/test_run.c:119
 bpf_prog_test_run_skb+0x9fb/0x1190 net/bpf/test_run.c:678
 bpf_prog_test_run+0x31c/0x390 kernel/bpf/syscall.c:3374
 __sys_bpf+0x5a5/0x6f0 kernel/bpf/syscall.c:4675
 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4759 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759
 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: 0033:0x7fdbc7f98159
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:00007fdbc61f0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fdbc821ffa0 RCX: 00007fdbc7f98159
RDX: 000000000000002c RSI: 0000200000000080 RDI: 000000000000000a
RBP: 00007fdbc802f06b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdbc8220038 R14: 00007fdbc821ffa0 R15: 00007ffde49b55f8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 7661 jiffies! g108637 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=42528
rcu: rcu_preempt kthread starved for 7667 jiffies! g108637 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27504 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x159/0x1b0 arch/x86/kernel/kvm.c:918
Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 4b 0f b6 1f e8 47 a5 4a 00 44 38 e3 75 10 66 90 0f 00 2d 89 d9 f3 08 fb f4 <e9> 16 ff ff ff fb e9 10 ff ff ff e8 b7 6c 8d 08 89 f9 80 e1 07 38
RSP: 0018:ffffc90000dd08a0 EFLAGS: 00000246
RAX: 568a172e7fd69f00 RBX: 0000000000000003 RCX: 568a172e7fd69f00
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4b80
RBP: ffffc90000dd0950 R08: ffffffff9021418f R09: 1ffffffff2042831
R10: dffffc0000000000 R11: fffffbfff2042832 R12: 0000000000000003
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920001ba114
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff0e20cbb0 CR3: 0000000073eca000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x605/0x9b0 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x265/0x2f0 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:364 [inline]
 tcp_write_timer+0x29/0x280 net/ipv4/tcp_timer.c:673
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730
Code: b7 48 89 df e8 c6 fc f2 f7 eb ad e8 af aa f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 37 62 5a 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000d67d48 EFLAGS: 000002c2
RAX: 568a172e7fd69f00 RBX: ffff88813fe68000 RCX: 568a172e7fd69f00
RDX: 0000000000000001 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4b80
RBP: ffffc90000d67e80 R08: ffff8880b913b30b R09: 1ffff11017227661
R10: dffffc0000000000 R11: ffffed1017227662 R12: 1ffff920001acfb4
R13: dffffc0000000000 R14: 1ffff11027fcd000 R15: 0000000000000000
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:202 [inline]
 do_idle+0x251/0x650 kernel/sched/idle.c:326
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:424
 start_secondary+0x32f/0x430 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.