glibc fixes resolver abort on long search domains

The GNU C Library has fixed a resolver bug that could abort processes when a search or domain entry in resolv.conf, or the LOCALDOMAIN environment variable, exceeded the internal name buffer.

Tracked as CVE-2026-8674, the flaw arose after configuration loading truncated an oversized search list. A later consistency check measured the truncated result against the wrong size limit, so the assertion failed and the process exited. Any application performing DNS lookups through the stub resolver was exposed to this crash under that configuration.

Adhemerval Zanella corrected the remaining-space test to use the actual name buffer and adjusted the empty-list case so a first entry that cannot fit is accepted without aborting. Tests now cover both the search and domain directives.