syzbot


invalid opcode in __traceiter_neigh_update

Status: upstream: reported C repro on 2025/08/30 20:53
Reported-by: syzbot+56a383bcf9a16491c3b7@syzkaller.appspotmail.com
First crash: 8h34m, last: 51m

Sample crash report:
CFI failure at __traceiter_neigh_update+0x9d/0xf0 include/trace/events/neigh.h:72 (target: 0xffffc90000187370; expected type: 0xcdd4cfdd)
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 23 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__traceiter_neigh_update+0x9d/0xf0 include/trace/events/neigh.h:72
Code: 05 e8 f7 4a b9 fd 49 8b 7e 08 48 8b 75 c8 48 8b 55 c0 44 89 e9 44 8b 45 d4 44 8b 4d d0 41 ba 23 30 2b 32 45 03 54 24 fc 74 02 <0f> 0b 41 ff d4 48 83 c3 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74
RSP: 0018:ffffc90000187370 EFLAGS: 00010282

RAX: 1ffff1102225c886 RBX: ffff8881112e4428 RCX: 0000000000000004
RDX: ffff888123431c56 RSI: ffff88811f6b5400 RDI: ffffc9000173f000
RBP: ffffc900001873b0 R08: 0000000000000001 R09: 0000000000000000
R10: 00000000d76b972f R11: 0000000000000100 R12: ffffffff817125c0
R13: 0000000000000004 R14: ffff8881112e4428 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000006e0f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 trace_neigh_update include/trace/events/neigh.h:72 [inline]
 __neigh_update+0x1f4b/0x2080 net/core/neighbour.c:1307
 neigh_update net/core/neighbour.c:1488 [inline]
 neigh_event_ns+0xb3/0x120 net/core/neighbour.c:1517
 arp_process+0x119c/0x1920 net/ipv4/arp.c:851
 NF_HOOK+0x14d/0x1a0 include/linux/netfilter.h:305
 arp_rcv+0x2ef/0x480 net/ipv4/arp.c:990
 __netif_receive_skb_list_ptype net/core/dev.c:5633 [inline]
 __netif_receive_skb_list_core+0x713/0x770 net/core/dev.c:5676
 __netif_receive_skb_list net/core/dev.c:5728 [inline]
 netif_receive_skb_list_internal+0x7d2/0xa60 net/core/dev.c:5819
 gro_normal_list include/net/gro.h:433 [inline]
 napi_complete_done+0x36f/0x790 net/core/dev.c:6160
 virtqueue_napi_complete drivers/net/virtio_net.c:403 [inline]
 virtnet_poll+0x991/0x1150 drivers/net/virtio_net.c:1717
 __napi_poll+0xd0/0x5e0 net/core/dev.c:6594
 napi_poll net/core/dev.c:6661 [inline]
 net_rx_action+0x49b/0xaa0 net/core/dev.c:6775
 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
 run_ksoftirqd+0x28/0x30 kernel/softirq.c:1019
 smpboot_thread_fn+0x4a0/0x910 kernel/smpboot.c:164
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:

---[ end trace 0000000000000000 ]---
RIP: 0010:__traceiter_neigh_update+0x9d/0xf0 include/trace/events/neigh.h:72
Code: 05 e8 f7 4a b9 fd 49 8b 7e 08 48 8b 75 c8 48 8b 55 c0 44 89 e9 44 8b 45 d4 44 8b 4d d0 41 ba 23 30 2b 32 45 03 54 24 fc 74 02 <0f> 0b 41 ff d4 48 83 c3 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74
RSP: 0018:ffffc90000187370 EFLAGS: 00010282

RAX: 1ffff1102225c886 RBX: ffff8881112e4428 RCX: 0000000000000004
RDX: ffff888123431c56 RSI: ffff88811f6b5400 RDI: ffffc9000173f000
RBP: ffffc900001873b0 R08: 0000000000000001 R09: 0000000000000000
R10: 00000000d76b972f R11: 0000000000000100 R12: ffffffff817125c0
R13: 0000000000000004 R14: ffff8881112e4428 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000006e0f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/30 22:40 android14-6.1 02ca81000485 807a3b61 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf invalid opcode in __traceiter_neigh_update
2025/08/30 20:47 android14-6.1 02ca81000485 807a3b61 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf invalid opcode in __traceiter_neigh_update
2025/08/30 14:57 android14-6.1 376207d1f3e2 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf invalid opcode in __traceiter_neigh_update
* Struck through repros no longer work on HEAD.