BUG: soft lockup in ipv6_rcv (3)

Status: premoderation: reported on 2026/08/15 11:00
Reported-by: syzbot+70b021e44210f555c1e9@syzkaller.appspotmail.com
First crash: 4d16h, last: 4d16h
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in ipv6_rcv (4) net 1 syz, C done done 12 459d 959d 0/29 auto-obsoleted due to no activity on 2025/08/26 02:53
android-5-10 BUG: soft lockup in ipv6_rcv (2) 1 1 132d 132d 0/2 auto-obsoleted due to no activity on 2026/07/08 15:39
upstream BUG: soft lockup in ipv6_rcv (2) net 1 1 1058d 1058d 0/29 closed as invalid on 2023/10/27 13:35
upstream BUG: soft lockup in ipv6_rcv net 1 24 2571d 2576d 0/29 auto-closed as invalid on 2019/10/25 14:11
upstream BUG: soft lockup in ipv6_rcv (3) net 1 1 315d 315d 0/29 closed as invalid on 2025/11/14 06:50
android-5-15 BUG: soft lockup in ipv6_rcv origin:lts 1 syz, C done 19 632d 852d 0/2 auto-obsoleted due to no activity on 2025/03/05 18:06
android-5-10 BUG: soft lockup in ipv6_rcv 1 3 748d 765d 0/2 auto-obsoleted due to no activity on 2024/10/30 14:49
linux-4.19 BUG: soft lockup in ipv6_rcv 1 syz, C error 25 1481d 1959d 0/1 upstream: reported C repro on 2021/04/08 17:19
upstream BUG: soft lockup in ipv6_rcv (4) net 1 1 256d 256d 0/29 closed as invalid on 2026/01/13 16:48
android-54 BUG: soft lockup in ipv6_rcv 1 1 828d 828d 0/2 auto-obsoleted due to no activity on 2024/08/11 06:11
linux-6.1 INFO: rcu detected stall in ipv6_rcv 1 1 45d 45d 0/3 upstream: reported on 2026/07/05 15:50
upstream INFO: rcu detected stall in ipv6_rcv (3) net 1 1 1177d 1177d 0/29 auto-obsoleted due to no activity on 2023/08/28 06:25
upstream INFO: rcu detected stall in ipv6_rcv (2) 1 syz, C done 550 1577d 2581d 0/29 auto-obsoleted due to no activity on 2023/04/19 23:54

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 123s! [syz.5.38989:6466]
Modules linked in:
CPU: 1 PID: 6466 Comm: syz.5.38989 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:update_stack_state+0x38a/0x490 arch/x86/kernel/unwind_frame.c:244
Code: e8 db ea 6f 00 48 8b 45 a0 49 89 06 49 89 c6 48 8b 45 a8 42 80 3c 28 00 48 8b 45 d0 4c 8d 78 58 74 08 4c 89 ff e8 b6 ea 6f 00 <49> c7 07 00 00 00 00 49 83 c6 08 eb 08 4c 8b 75 88 49 83 ee 80 48
RSP: 0018:ffffc900001700a8 EFLAGS: 00000246
RAX: ffffc900001701c8 RBX: ffffc900001701d0 RCX: ffffc90000170f01
RDX: ffffc90000170fe8 RSI: 1ffff9200002e03a RDI: ffffc90000170220
RBP: ffffc90000170158 R08: ffffc90000170290 R09: ffffc90000170288
R10: 0000000000000014 R11: fffff5200002e045 R12: 1ffff9200002e041
R13: dffffc0000000000 R14: ffffc90000170fe8 R15: ffffc90000170220
FS:  00007fc4ef54f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555583b644e8 CR3: 0000000122fe5000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 unwind_next_frame+0x39e/0x670 arch/x86/kernel/unwind_frame.c:316
 arch_stack_walk+0x108/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:121
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1600 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626
 slab_free mm/slub.c:3208 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3224
 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:695 [inline]
 kfree_skb+0xc1/0x2f0 net/core/skbuff.c:713
 ip6_mc_input+0x22b/0x290 net/ipv6/ip6_input.c:574
 dst_input include/net/dst.h:461 [inline]
 ip6_rcv_finish+0x18c/0x360 net/ipv6/ip6_input.c:80
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0xf0/0x230 net/ipv6/ip6_input.c:301
 __netif_receive_skb_one_core net/core/dev.c:5413 [inline]
 __netif_receive_skb+0xc8/0x280 net/core/dev.c:5527
 netif_receive_skb_internal net/core/dev.c:5632 [inline]
 netif_receive_skb+0x9b/0x3e0 net/core/dev.c:5691
 br_netif_receive_skb net/bridge/br_input.c:30 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 br_pass_frame_up+0x164/0x1e0 net/bridge/br_input.c:72
 br_handle_frame_finish+0xce7/0x10f0 net/bridge/br_input.c:179
 nf_hook_bridge_pre net/bridge/br_input.c:259 [inline]
 br_handle_frame+0x406/0x8e0 net/bridge/br_input.c:363
 __netif_receive_skb_core+0xed5/0x30b0 net/core/dev.c:5307
 __netif_receive_skb_one_core net/core/dev.c:5411 [inline]
 __netif_receive_skb+0x72/0x280 net/core/dev.c:5527
 process_backlog+0x351/0x600 net/core/dev.c:6434
 napi_poll net/core/dev.c:6885 [inline]
 net_rx_action+0x48d/0xed0 net/core/dev.c:6955
 __do_softirq+0x255/0x563 kernel/softirq.c:309
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x60/0x80 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:405 [inline]
 __irq_exit_rcu+0x128/0x150 kernel/softirq.c:435
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:447
 sysvec_apic_timer_interrupt+0xbf/0xe0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635
RIP: 0010:__sanitizer_cov_trace_pc+0x59/0x60 kernel/kcov.c:205
Code: 2c 8b 91 b8 0a 00 00 83 fa 02 75 21 48 8b 91 c0 0a 00 00 48 8b 32 48 8d 7e 01 8b 89 bc 0a 00 00 48 39 cf 73 08 48 89 44 f2 08 <48> 89 3a 5d c3 66 90 55 48 89 e5 48 8b 45 08 65 48 8b 15 50 bb 9d
RSP: 0018:ffffc90000e46fd0 EFLAGS: 00000287
RAX: ffffffff825b95d1 RBX: ffffffff85790f28 RCX: 0000000000080000
RDX: ffffc90006a7a000 RSI: 00000000000014b1 RDI: 00000000000014b2
RBP: ffffc90000e46fd0 R08: ffffc90000e46f57 R09: ffffc90000e46f40
R10: dffffc0000000000 R11: fffff520001c8deb R12: ffff0a01ffffff10
R13: ffffe8fffed220bd R14: 0000000000000020 R15: ffffffff85790f28
 vsnprintf+0xf81/0x1990 lib/vsprintf.c:2639
 vscnprintf lib/vsprintf.c:2792 [inline]
 scnprintf+0xe5/0x180 lib/vsprintf.c:2846
 tipc_list_dump+0x75/0x2f0 net/tipc/trace.c:179
 tipc_sk_dump+0xa27/0xfd0 net/tipc/socket.c:3998
 perf_trace_tipc_sk_class+0x3cc/0x5e0 net/tipc/trace.h:205
 trace_tipc_sk_filter_rcv net/tipc/trace.h:228 [inline]
 tipc_sk_filter_rcv+0x36f2/0x3860 net/tipc/socket.c:2349
 tipc_sk_backlog_rcv+0x10c/0x220 net/tipc/socket.c:2410
 sk_backlog_rcv include/net/sock.h:1071 [inline]
 __release_sock+0x146/0x360 net/core/sock.c:2589
 release_sock+0x60/0x1b0 net/core/sock.c:3142
 tipc_wait_for_rcvmsg+0x2d7/0x5e0 net/tipc/socket.c:1852
 tipc_recvstream+0x1f4/0xe70 net/tipc/socket.c:2043
 ____sys_recvmsg+0x2ca/0x5b0 net/socket.c:-1
 ___sys_recvmsg+0x213/0x5c0 net/socket.c:2638
 __sys_recvmsg net/socket.c:2668 [inline]
 __do_sys_recvmsg net/socket.c:2678 [inline]
 __se_sys_recvmsg net/socket.c:2675 [inline]
 __x64_sys_recvmsg+0x1fe/0x2d0 net/socket.c:2675
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fc4f0af60d9
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:00007fc4ef54f028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007fc4f0d7dfa0 RCX: 00007fc4f0af60d9
RDX: 0000000000001f00 RSI: 0000200000000500 RDI: 0000000000000005
RBP: 00007fc4f0b8d024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc4f0d7e038 R14: 00007fc4f0d7dfa0 R15: 00007ffc190163f8
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6487 Comm: kworker/u4:3 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:229 [inline]
RIP: 0010:smp_call_function_single+0x211/0x490 kernel/smp.c:517
Code: ff e8 b3 90 0a 00 41 83 e6 01 49 bc 00 00 00 00 00 fc ff df 75 0a e8 ee 8c 0a 00 e9 a4 00 00 00 f3 90 f7 44 24 48 01 00 00 00 <0f> 84 8f 00 00 00 e8 d4 8c 0a 00 eb e9 e8 ad 95 22 03 89 c3 41 89
RSP: 0018:ffffc9000172f700 EFLAGS: 00000202
RAX: ffffffff815a24ec RBX: 0000000000000000 RCX: ffff88814d620000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000172f7f0 R08: ffff8881f7157647 R09: 1ffff1103ee2aec8
R10: dffffc0000000000 R11: ffffed103ee2aec9 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff920002e5ee4
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4824fad81d CR3: 000000000640f000 CR4: 00000000003506b0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 smp_call_function_many_cond+0x8f5/0x9d0 kernel/smp.c:653
 smp_call_function_many kernel/smp.c:716 [inline]
 smp_call_function kernel/smp.c:738 [inline]
 on_each_cpu+0xab/0x180 kernel/smp.c:837
 text_poke_sync arch/x86/kernel/alternative.c:1568 [inline]
 text_poke_bp_batch+0x1cb/0x5f0 arch/x86/kernel/alternative.c:1768
 text_poke_flush arch/x86/kernel/alternative.c:1959 [inline]
 text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1966
 arch_jump_label_transform_apply+0x15/0x30 arch/x86/kernel/jump_label.c:126
 __jump_label_update+0x38f/0x3b0 kernel/jump_label.c:459
 jump_label_update+0x34c/0x3e0 kernel/jump_label.c:825
 static_key_enable_cpuslocked+0x126/0x240 kernel/jump_label.c:177
 static_key_enable+0x1a/0x30 kernel/jump_label.c:190
 toggle_allocation_gate+0xba/0x440 mm/kfence/core.c:624
 process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
 worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
 kthread+0x324/0x3b0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/15 10:59 android13-5.10-lts e334a66065d3 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10-perf BUG: soft lockup in ipv6_rcv
* Struck through repros no longer work on HEAD.