Bug#997912: libc6: tinydns stops replying to queries after libc6 upgrade from 2.31 to 2.32

[Emil <ez@vajn.icu>]

Package: libc6
Version: 2.32-4
Severity: important

-- System Information:
Debian Release: bookworm/sid
  APT prefers testing
  APT policy: (700, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.16.0-1-amd64 (SMP w/2 CPU threads)
Kernel taint flags: TAINT_WARN
Locale: LANG=C.UTF-8, LC_CTYPE=ro_RO (charmap=ISO-8859-2), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages libc6 depends on:
ii  libgcc-s1  11.2.0-2

Versions of packages libc6 recommends:
ii  libidn2-0  2.3.2-2

Versions of packages libc6 suggests:
ii  debconf [debconf-2.0]  1.5.77
pn  glibc-doc              <none>
ii  libc-l10n              2.32-4
ii  libnss-nis             3.1-4
ii  libnss-nisplus         1.3-4
ii  locales                2.32-4

-- debconf information excluded

After upgrading libc6 from 2.31 to 2.32 tinydns stops replying to
queries after a while.

None of the tinydns files have been changed when this bug started
manifesting (nor the ELF or its data files).

Any version of libc6 2.32-1/2/3/4 will cause tinydns to ignore queries
after a while. dnscache runing on the same machine is not affected.

tinydns doesn't crash and there is nothing unusual in its logfiles.
If I kill the tinydns daemon then supervise will spawn another version
and it starts working again for a while, then stops replying to queries.

Rolling back libc6 to version 2.31-17 makes tinydns work normal again.