nsswitch: handle missing actions properly

Temporary fix for https://bugzilla.redhat.com/show_bug.cgi?id=1906066

glibc-rh1906066.patch

@@ -0,0 +1,59 @@
+From d74a39158ab4aafa8af874e996bf5ddbde593bc0 Mon Sep 17 00:00:00 2001
+From: DJ Delorie <dj@redhat.com>
+Date: Wed, 9 Dec 2020 21:46:30 -0500
+Subject: nsswitch: handle missing actions properly
+
+Some internal functions need to know if a database has a nonzero
+list of actions; success getting the database does not guarantee
+that.  Add checks for such as needed.
+
+Skip the ":" in each nsswitch.conf line so as not to add a dummy
+action libnss_:.so
+
+diff --git a/grp/initgroups.c b/grp/initgroups.c
+index a60ca1c395..a0a836d862 100644
+--- a/grp/initgroups.c
++++ b/grp/initgroups.c
+@@ -72,11 +72,13 @@ internal_getgrouplist (const char *user, gid_t group, long int *size,
+ 
+   nss_action_list nip;
+ 
+-  if (__nss_database_get (nss_database_initgroups, &nip))
++  if (__nss_database_get (nss_database_initgroups, &nip)
++      && nip != NULL)
+     {
+       use_initgroups_entry = true;
+     }
+-  else if (__nss_database_get (nss_database_group, &nip))
++  else if (__nss_database_get (nss_database_group, &nip)
++      && nip != NULL)
+     {
+       use_initgroups_entry = false;
+     }
+diff --git a/nss/nss_database.c b/nss/nss_database.c
+index e8c307d1f3..a036e95fbf 100644
+--- a/nss/nss_database.c
++++ b/nss/nss_database.c
+@@ -212,7 +212,8 @@ process_line (struct nss_database_data *data, char *line)
+   if (line[0] == '\0' || name == line)
+     /* Syntax error.  Skip this line.  */
+     return true;
+-  *line++ = '\0';
++  while (line[0] != '\0' && (isspace (line[0]) || line[0] == ':'))
++    *line++ = '\0';
+ 
+   int db = name_to_database_index (name);
+   if (db < 0)
+diff --git a/nss/nsswitch.c b/nss/nsswitch.c
+index 40109c744d..921062e04f 100644
+--- a/nss/nsswitch.c
++++ b/nss/nsswitch.c
+@@ -81,7 +81,7 @@ __nss_database_lookup2 (const char *database, const char *alternate_name,
+   if (database_names[database_id] == NULL)
+     return -1;
+ 
+-  if (__nss_database_get (database_id, ni))
++  if (__nss_database_get (database_id, ni) && *ni)
+     {
+       /* Success.  */
+       return 0;

glibc.spec

@@ -100,7 +100,7 @@
 Summary: The GNU libc libraries
 Name: glibc
 Version: %{glibcversion}
-Release: 19%{?dist}
+Release: 20%{?dist}
 
 # In general, GPLv2+ is used by programs, LGPLv2+ is used for
 # libraries.
@@ -162,6 +162,9 @@ Patch29: glibc-fedora-nsswitch.patch
 Patch30: glibc-deprecated-selinux-makedb.patch
 Patch31: glibc-deprecated-selinux-nscd.patch
 
+# Temporary until official patch is committed upstream
+Patch99: glibc-rh1906066.patch
+
 ##############################################################################
 # Continued list of core "glibc" package information:
 ##############################################################################
@@ -2258,6 +2261,9 @@ fi
 %files -f compat-libpthread-nonshared.filelist -n compat-libpthread-nonshared
 
 %changelog
+* Wed Dec 09 2020 DJ Delorie <dj@redhat.com> - 2.32.9000-20
+- nsswitch: handle missing actions properly (temporary fix for 1906066)
+
 * Mon Dec 07 2020 Arjun Shankar <arjun@redhat.com> - 2.32.9000-19
 - Auto-sync with upstream branch master,
   commit 088e9625378f25607acff3daf7a79cbdee497043: