ipv6: exthdrs: refresh nh after handling HAO option

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv6: exthdrs: refresh nh after handling HAO option ip6_parse_tlv() caches skb_network_header(skb) in nh while walking IPv6 TLVs. ipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can move the skb head and invalidate the cached network header pointer. Refresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs are parsed from the current skb head. This matches the existing pattern used in ip6_parse_tlv() after helpers that can modify skb header storage.

Timeline

1. Jul 19, 2026, 2:55 PM UTCCVE published
2. Oct 16, 2026, 3:33 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: total

3. Oct 19, 2026, 8:17 PM UTCRecord last updated

Affected versions

• Linux Linux

  From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in b3ac54e5c905f86d22b502eacb5686a282c5659f; From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in f8aabed3ff3e986920cf02a2a2785e08e586b234; From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in 1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1; From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in 12d957979e4a800167842f1b42be6a606d227ebe; From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in ff375ed1cba81392346c5bfbf0bb7a13b2946f99; From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in 751db1b802a067b7fff25880f4e9f9152a171538; From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in 9b6dcc0a39fd71752937f0b6b3973e1416085dcf; From a831f5bbc89a9978795504be9e1ff412043f8f77 · fixed in f7b52afe3592eae66e160586b45a3f2242972c63

• Linux Linux

  2.6.19

• KernelLinux

  From 2.6.19 · fixed in 5.10.259; From 5.11.0 · fixed in 5.15.210; From 5.16.0 · fixed in 6.1.176; From 6.2.0 · fixed in 6.6.143; From 6.7.0 · fixed in 6.12.93; From 6.13.0 · fixed in 6.18.35; From 6.19.0 · fixed in 7.0.12

References 8