CVE-2026-52921: netfilter: ipset: stop hash:* range iteration at end

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

netfilter: ipset: stop hash: range iteration at end

The following hash set variants:

hash:ip,mark hash:ip,port hash:ip,port,ip hash:ip,port,net

iterate IPv4 ranges with a 32-bit iterator.

The iterator must stop once the last address in the requested range has been processed. Advancing it once more can move the traversal state past the end of the request, so a later retry may continue from an unintended position.

Handle the iterator increment explicitly at the end of the loop and stop once the upper bound has been processed. This keeps the existing retry behaviour intact for valid ranges while preventing traversal from continuing past the original boundary.