CVE-2026-98089: bonding: alb: fix uninitialized transport header access in alb_determine_nd()

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: bonding: alb: fix uninitialized transport header access in alb_determine_nd() alb_determine_nd() uses icmp6_hdr(skb) to inspect ICMPv6 headers. However, in xmit paths (e.g. packets sent via AF_PACKET / raw sockets or forwarded packets), skb->transport_header is not guaranteed to be initialized. While pskb_network_may_pull() ensures the packet data is linear starting from the network header, it does not set or adjust the transport header offset. Dereferencing icmp6_hdr(skb) can therefore access out-of-bounds memory. Fetch the icmp6hdr directly after ipv6hdr following pskb_network_may_pull(), and reload ipv6hdr in case pskb_may_pull() reallocated skb->head. Also remove the unused bond argument from alb_determine_nd().

Affected products

Linux kernel: 5.18 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

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