Fix a memory leak in local_soa() on FreeBSD - #110
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by calling res_ndestroy() to free memory allocated by res_ninit(). Unless the unicats SOA heuristic is turned off explicitly with `mdns.allow` as described in https://github.com/avahi/nss-mdns?tab=readme-ov-file#etcmdnsallow nss-mdns without this patch leaks memory every time forward lookups are performed with gethostbyname() (with the default documented configuration where `mdns*` comes after `files` and before `dns` in `nsswitch.conf`). local_soa() has been using `res_nclose` instead of `res_ndestroy` since it was introduced in 8dd7984 but the FreeBSD support was removed in 1bd4895 and then brought back in fdd3293 so probably only the versions containing fdd3293 like 0.15 and 0.15.1 are affected. Fixes ``` ==49966== 904 bytes in 1 blocks are definitely lost in loss record 9 of 12 ==49966== at 0x4856304: malloc (vg_replace_malloc.c:451) ==49966== by 0x49742DE: __res_vinit (in /lib/libc.so.7) ==49966== by 0x4B6BFF9: local_soa (util.c:134) ==49966== by 0x4B6BDC1: verify_name_allowed_with_soa (util.c:69) ==49966== by 0x4B6CBE0: _nss_mdns_gethostbyname_impl (nss.c:122) ==49966== by 0x4B6CDF5: _nss_mdns_minimal_gethostbyname3_r (nss.c:201) ==49966== by 0x4B6CEBB: _nss_mdns_minimal_gethostbyname2_r (nss.c:215) ==49966== by 0x4B6DCF1: __nss_bsdcompat_gethostbyname2_r (bsdnss.c:265) ==49966== by 0x49540CC: nsdispatch (in /lib/libc.so.7) ==49966== by 0x49484CF: ??? (in /lib/libc.so.7) ==49966== by 0x49481E0: gethostbyname_r (in /lib/libc.so.7) ==49966== by 0x4948F04: gethostbyname (in /lib/libc.so.7) ==49966== ``` Closes avahi#105
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https://github.com/evverx/avahi/actions/runs/19760939741/job/56622496914?pr=3 is green so I'll go ahead and merge it. |
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Nov 28, 2025
Now that avahi/nss-mdns#110 is merged the test can be run under Valgrind on FreeBSD as well.
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by calling res_ndestroy() to free memory allocated by res_ninit().
Unless the unicats SOA heuristic is turned off explicitly with
mdns.allowas described inhttps://github.com/avahi/nss-mdns?tab=readme-ov-file#etcmdnsallow nss-mdns without this patch leaks memory every time forward lookups are performed with gethostbyname() (with the default documented configuration where
mdns*comes afterfilesand beforednsinnsswitch.conf).local_soa() has been using
res_ncloseinstead ofres_ndestroysince it was introduced in 8dd7984 but the FreeBSD support was removed in 1bd4895 and then brought back in fdd3293 so probably only the versions containingfdd3293 like 0.15 and 0.15.1 are affected.
Fixes
Closes #105