CVE-2026-97940

In the Linux kernel, the following vulnerability has been resolved:

ipv6: fix fib6 walker UAF on seq stop

ipv6_route_iter_active() treats a walker in FWS_U at the table root as

already unlinked. fib6_del_route() can move a still-linked walker into

that same state when the current leaf is the last route at the root,

so ipv6_route_native_seq_stop() skips fib6_walker_unlink(). The seq

private object can then be freed while it remains on

net->ipv6.fib6_walkers. A later route deletion walks the dangling list

and uses the freed walker.

Use the list head as membership state and reinitialize it when

unlinking. Keep the existing w->node check so a never-started iterator

with a zeroed private object is not treated as linked.

The same stop helper is used by /proc/net/ipv6_route and by the BPF

ipv6_route iterator. The BPF show path only widens the race.