WARNING in set_ipv6_addr

Status: upstream: reported C repro on 2026/09/30 17:02
Subsystems: openvswitch
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+4cc63fcfb3845e149969@syzkaller.appspotmail.com
Fix commit: 3c6a4b11330f net: openvswitch: validate transport header presence in set_ipv6_addr
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root]
First crash: 25d, last: 9d09h
Cause bisection: introduced by (bisect log) :
commit af81cb247ca94e4bcfea31ea862cf3aaf955a503
Author: Jeff Layton <jlayton@kernel.org>
Date: Wed Mar 25 14:40:28 2026 +0000

  sunrpc: add a generic netlink family for cache upcalls

Crash: WARNING in set_ipv6_addr (log)
Repro: C syz .config
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
375780e3 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ✅ PeripheralTrigger: ✅ RemoteTrigger: ✅ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ✅ VMHostTrigger: ❌ ❓ WARNING in set_ipv6_addr 2026/10/01 01:32 2026/10/01 01:32 2026/10/01 02:16 38f7f0d1
▶ ▼ Discussions (4)
Title Replies (including bot) Last reply
[PATCH net v3] net: openvswitch: validate transport header presence in set_ipv6_addr 3 (3) 2026/10/08 18:50
[PATCH net v2] net: openvswitch: validate transport header presence in set_ipv6_addr 3 (3) 2026/10/08 10:33
[PATCH net] net: openvswitch: validate transport header presence in set_ipv6_addr 7 (7) 2026/10/02 06:34
[syzbot] [openvswitch?] WARNING in set_ipv6_addr 1 (3) 2026/10/01 03:36

Sample crash report:
ovs-dp0: entered promiscuous mode
------------[ cut here ]------------
!skb_transport_header_was_set(skb)
WARNING: ./include/linux/skbuff.h:3075 at skb_transport_header include/linux/skbuff.h:3075 [inline], CPU#1: syz-executor189/5629
WARNING: ./include/linux/skbuff.h:3075 at skb_transport_offset include/linux/skbuff.h:3250 [inline], CPU#1: syz-executor189/5629
WARNING: ./include/linux/skbuff.h:3075 at update_ipv6_checksum net/openvswitch/actions.c:361 [inline], CPU#1: syz-executor189/5629
WARNING: ./include/linux/skbuff.h:3075 at set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399, CPU#1: syz-executor189/5629
Modules linked in:
CPU: 1 UID: 0 PID: 5629 Comm: syz-executor189 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:skb_transport_header include/linux/skbuff.h:3075 [inline]
RIP: 0010:skb_transport_offset include/linux/skbuff.h:3250 [inline]
RIP: 0010:update_ipv6_checksum net/openvswitch/actions.c:361 [inline]
RIP: 0010:set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399
Code: f6 e8 22 d3 05 00 ba 10 00 00 00 4c 89 ef 48 89 ee 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d e9 34 ce 7a f6 e8 3f c7 0a f6 90 <0f> 0b 90 48 8b 44 24 10 42 0f b6 04 30 84 c0 0f 85 c8 01 00 00 41
RSP: 0018:ffffc90003a96e68 EFLAGS: 00010293
RAX: ffffffff8bbd26d1 RBX: 000000000000ffff RCX: ffff888075d8ddc0
RDX: 0000000000000000 RSI: 000000000000ffff RDI: 000000000000ffff
RBP: 000000000000004c R08: 0000000000000001 R09: 0000000000000011
R10: 000000000000001f R11: 0000000000000000 R12: ffff888071873d36
R13: ffff88807aaa6a96 R14: dffffc0000000000 R15: ffff888071873c80
FS:  000055557e6b8400(0000) GS:ffff888124dc7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000069f000 CR3: 0000000072c2a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 set_ipv6 net/openvswitch/actions.c:531 [inline]
 execute_masked_set_action net/openvswitch/actions.c:1073 [inline]
 do_execute_actions+0x557e/0x8600 net/openvswitch/actions.c:1366
 ovs_execute_actions+0xde/0x520 net/openvswitch/actions.c:1592
 ovs_packet_cmd_execute+0xb4f/0xf10 net/openvswitch/datapath.c:705
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2575
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1364
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
 __sock_sendmsg net/socket.c:815 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2713
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
 __sys_sendmsg net/socket.c:2799 [inline]
 __do_sys_sendmsg net/socket.c:2804 [inline]
 __se_sys_sendmsg net/socket.c:2802 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efc521a8d39
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc7d204dc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffc7d204ef8 RCX: 00007efc521a8d39
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffc7d204ef8 R09: 00007ffc7d204ef8
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc7d204ee8
R13: 0000000000000002 R14: 00007efc52239ca0 R15: 0000000000000002
 </TASK>

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/08 04:36 net 6d25ffca055a 6520ecdb .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in set_ipv6_addr
2026/10/01 01:47 bpf 564b7e8e09ec 892a21ec .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce WARNING in set_ipv6_addr
2026/09/30 15:59 net-next 47a144672573 892a21ec .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in set_ipv6_addr
2026/09/30 15:36 bpf-next 99c3e74f8d96 892a21ec .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING in set_ipv6_addr
2026/09/30 14:55 net-next 47a144672573 892a21ec .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in set_ipv6_addr
2026/10/15 03:32 bpf ff47652a4b66 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce WARNING in set_ipv6_addr
2026/10/16 08:10 bpf-next 0b4855d443cf 3f2522c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING in set_ipv6_addr
2026/10/16 08:10 bpf-next 0b4855d443cf 3f2522c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING in set_ipv6_addr
2026/10/14 22:09 bpf-next 763187dbbf83 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING in set_ipv6_addr
2026/10/04 15:54 bpf-next 99dc1ba54242 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING in set_ipv6_addr
2026/09/30 14:18 net-next 47a144672573 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in set_ipv6_addr
* Struck through repros no longer work on HEAD.