CVE-2026-99071

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

ipv4: do not warn on route notification size race

Commit 680aea08e78c ('net: ipv4: Emit notification when fib hardware
flags are changed') added asynchronous route notifications for hardware
flag changes.

fib_alias_hw_flags_set() sizes the skb with fib_nlmsg_size() and later
fills it with fib_dump_info() while holding only RCU. With nexthop
compatibility mode enabled, a concurrent replacement can grow the group
between these independent snapshots. fib_dump_info() can then
legitimately return -EMSGSIZE, so the warning does not prove a sizing bug.

Remove the warning. The existing error path still frees the skb and
reports the error to listeners.