From 3c229a9afb670025a3c1792bf5ac233b5a566ec5 Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Sun, 6 Dec 2020 22:41:35 +0900 Subject: [PATCH] nss-resolve: varlink_call() set error_id only when r >= 0 Fixes #17870. --- src/nss-resolve/nss-resolve.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/src/nss-resolve/nss-resolve.c b/src/nss-resolve/nss-resolve.c index 566b319484..3fee4f5813 100644 --- a/src/nss-resolve/nss-resolve.c +++ b/src/nss-resolve/nss-resolve.c @@ -200,16 +200,17 @@ enum nss_status _nss_resolve_gethostbyname4_r( if (r < 0) goto fail; + /* Return NSS_STATUS_UNAVAIL when communication with systemd-resolved fails, allowing falling + * back to other nss modules. Treat all other error conditions as NOTFOUND. This includes + * DNSSEC errors and suchlike. (We don't use UNAVAIL in this case so that the nsswitch.conf + * configuration can distinguish such executed but negative replies from complete failure to + * talk to resolved). */ r = varlink_call(link, "io.systemd.Resolve.ResolveHostname", cparams, &rparams, &error_id, NULL); - if (r < 0) { + if (r < 0) + goto fail; + if (!isempty(error_id)) { if (!error_shall_fallback(error_id)) goto not_found; - - /* Return NSS_STATUS_UNAVAIL when communication with systemd-resolved fails, allowing falling - back to other nss modules. Treat all other error conditions as NOTFOUND. This includes - DNSSEC errors and suchlike. (We don't use UNAVAIL in this case so that the nsswitch.conf - configuration can distinguish such executed but negative replies from complete failure to - talk to resolved). */ goto fail; } @@ -352,10 +353,11 @@ enum nss_status _nss_resolve_gethostbyname3_r( goto fail; r = varlink_call(link, "io.systemd.Resolve.ResolveHostname", cparams, &rparams, &error_id, NULL); - if (r < 0) { + if (r < 0) + goto fail; + if (!isempty(error_id)) { if (!error_shall_fallback(error_id)) goto not_found; - goto fail; } @@ -555,10 +557,11 @@ enum nss_status _nss_resolve_gethostbyaddr2_r( goto fail; r = varlink_call(link, "io.systemd.Resolve.ResolveAddress", cparams, &rparams, &error_id, NULL); - if (r < 0) { + if (r < 0) + goto fail; + if (!isempty(error_id)) { if (!error_shall_fallback(error_id)) goto not_found; - goto fail; }