Linux Kernel Route Notification Size Race Vulnerability

CVE-2026-99070

What is CVE-2026-99070?

In the Linux kernel, a race condition vulnerability was identified in the way route notifications are handled within the ipv6 protocol. The function fib6_info_hw_flags_set() incorrectly triggered warnings due to the interactions between size calculations and concurrent replacement operations. Specifically, when nexthop compatibility mode is enabled, the size of the notification could grow between polling actions, leading to legitimate responses being flagged as erroneous. This update resolves the extraneous warnings while maintaining the existing error handling procedures.

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