From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 5 May 2021 16:57:30 +0000 (+0200)
Subject: nss-systemd: properly handle empty membership lists
X-Git-Tag: v249-rc1~280^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F19531%2Fhead;p=thirdparty%2Fsystemd.git

nss-systemd: properly handle empty membership lists

When we are queried for membership lists on a system that has exactly
zero, then we'll return ESRCH immediately instead of at EOF. Which is
OK, but we need to handle this in various places, and not get confused
by it.
---

diff --git a/src/nss-systemd/nss-systemd.c b/src/nss-systemd/nss-systemd.c
index 185cb3de24e..3ac57441d9f 100644
--- a/src/nss-systemd/nss-systemd.c
+++ b/src/nss-systemd/nss-systemd.c
@@ -441,7 +441,7 @@ enum nss_status _nss_systemd_getgrent_r(
                         getgrent_data.iterator = userdb_iterator_free(getgrent_data.iterator);
 
                         r = membershipdb_all(nss_glue_userdb_flags(), &getgrent_data.iterator);
-                        if (r < 0) {
+                        if (r < 0 && r != -ESRCH) {
                                 UNPROTECT_ERRNO;
                                 *errnop = -r;
                                 return NSS_STATUS_UNAVAIL;
@@ -454,7 +454,7 @@ enum nss_status _nss_systemd_getgrent_r(
                         return NSS_STATUS_UNAVAIL;
                 } else if (!STR_IN_SET(gr->group_name, root_group.gr_name, nobody_group.gr_name)) {
                         r = membershipdb_by_group_strv(gr->group_name, nss_glue_userdb_flags(), &members);
-                        if (r < 0) {
+                        if (r < 0 && r != -ESRCH) {
                                 UNPROTECT_ERRNO;
                                 *errnop = -r;
                                 return NSS_STATUS_UNAVAIL;
@@ -465,6 +465,9 @@ enum nss_status _nss_systemd_getgrent_r(
         if (getgrent_data.by_membership) {
                 _cleanup_(_nss_systemd_unblockp) bool blocked = false;
 
+                if (!getgrent_data.iterator)
+                        return NSS_STATUS_NOTFOUND;
+
                 for (;;) {
                         _cleanup_free_ char *user_name = NULL, *group_name = NULL;
 
diff --git a/src/nss-systemd/userdb-glue.c b/src/nss-systemd/userdb-glue.c
index 0cc84bfac7c..8f8988579b8 100644
--- a/src/nss-systemd/userdb-glue.c
+++ b/src/nss-systemd/userdb-glue.c
@@ -216,7 +216,7 @@ enum nss_status userdb_getgrnam(
         }
 
         r = membershipdb_by_group_strv(name, nss_glue_userdb_flags(), &members);
-        if (r < 0) {
+        if (r < 0 && r != -ESRCH) {
                 *errnop = -r;
                 return NSS_STATUS_UNAVAIL;
         }
@@ -309,7 +309,7 @@ enum nss_status userdb_getgrgid(
                 from_nss = false;
 
         r = membershipdb_by_group_strv(g->group_name, nss_glue_userdb_flags(), &members);
-        if (r < 0) {
+        if (r < 0 && r != -ESRCH) {
                 *errnop = -r;
                 return NSS_STATUS_UNAVAIL;
         }