usermod: allow all group types with -G option

The only way of removing a group from the supplementary list is to use
-G option, and list all groups that the user is a member of except for
the one that wants to be removed. The problem lies when there's a user
that contains both local and remote groups, and the group to be removed
is a local one. As we need to include the remote group with -G option
the command will fail.

This reverts commit 140510de9de4771feb3af1d859c09604043a4c9b. This way,
it would be possible to remove the remote groups from the supplementary
list.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1967641
Resolves: https://github.com/shadow-maint/shadow/issues/338

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

diff --git a/src/usermod.c b/src/usermod.c
index 03bb9b9de1044d28f698a739538723a0e8389be0..a0c03afa630bc90834640c605509fb6a0dc2a2c1 100644 (file)
--- a/src/usermod.c
+++ b/src/usermod.c
@@ -187,7 +187,6 @@ static bool sub_gid_locked = false;
 static void date_to_str (/*@unique@*//*@out@*/char *buf, size_t maxsize,
                          long int date);
 static int get_groups (char *);
-static struct group * get_local_group (char * grp_name);
 static /*@noreturn@*/void usage (int status);
 static void new_pwent (struct passwd *);
 static void new_spent (struct spwd *);
@@ -201,9 +200,7 @@ static void grp_update (void);
 
 static void process_flags (int, char **);
 static void close_files (void);
-static void close_group_files (void);
 static void open_files (void);
-static void open_group_files (void);
 static void usr_update (void);
 static void move_home (void);
 static void update_lastlog (void);
@@ -260,11 +257,6 @@ static int get_groups (char *list)
                return 0;
        }
 
-       /*
-        * Open the group files
-        */
-       open_group_files ();
-
        /*
         * So long as there is some data to be converted, strip off each
         * name and look it up. A mix of numerical and string values for
@@ -284,7 +276,7 @@ static int get_groups (char *list)
                 * Names starting with digits are treated as numerical GID
                 * values, otherwise the string is looked up as is.
                 */
-               grp = get_local_group (list);
+               grp = prefix_getgr_nam_gid (list);
 
                /*
                 * There must be a match, either by GID value or by
@@ -334,8 +326,6 @@ static int get_groups (char *list)
                gr_free ((struct group *)grp);
        } while (NULL != list);
 
-       close_group_files ();
-
        user_groups[ngroups] = (char *) 0;
 
        /*
@@ -348,44 +338,6 @@ static int get_groups (char *list)
        return 0;
 }
 
-/*
- * get_local_group - checks if a given group name exists locally
- *
- *     get_local_group() checks if a given group name exists locally.
- *     If the name exists the group information is returned, otherwise NULL is
- *     returned.
- */
-static struct group * get_local_group(char * grp_name)
-{
-       const struct group *grp;
-       struct group *result_grp = NULL;
-       long long int gid;
-       char *endptr;
-
-       gid = strtoll (grp_name, &endptr, 10);
-       if (   ('\0' != *grp_name)
-               && ('\0' == *endptr)
-               && (ERANGE != errno)
-               && (gid == (gid_t)gid)) {
-               grp = gr_locate_gid ((gid_t) gid);
-       }
-       else {
-               grp = gr_locate(grp_name);
-       }
-
-       if (grp != NULL) {
-               result_grp = __gr_dup (grp);
-               if (NULL == result_grp) {
-                       fprintf (stderr,
-                                       _("%s: Out of memory. Cannot find group '%s'.\n"),
-                                       Prog, grp_name);
-                       fail_exit (E_GRP_UPDATE);
-               }
-       }
-
-       return result_grp;
-}
-
 #ifdef ENABLE_SUBIDS
 struct ulong_range
 {
@@ -1523,7 +1475,50 @@ static void close_files (void)
        }
 
        if (Gflg || lflg) {
-               close_group_files ();
+               if (gr_close () == 0) {
+                       fprintf (stderr,
+                                _("%s: failure while writing changes to %s\n"),
+                                Prog, gr_dbname ());
+                       SYSLOG ((LOG_ERR,
+                                "failure while writing changes to %s",
+                                gr_dbname ()));
+                       fail_exit (E_GRP_UPDATE);
+               }
+#ifdef SHADOWGRP
+               if (is_shadow_grp) {
+                       if (sgr_close () == 0) {
+                               fprintf (stderr,
+                                        _("%s: failure while writing changes to %s\n"),
+                                        Prog, sgr_dbname ());
+                               SYSLOG ((LOG_ERR,
+                                        "failure while writing changes to %s",
+                                        sgr_dbname ()));
+                               fail_exit (E_GRP_UPDATE);
+                       }
+               }
+#endif
+#ifdef SHADOWGRP
+               if (is_shadow_grp) {
+                       if (sgr_unlock () == 0) {
+                               fprintf (stderr,
+                                        _("%s: failed to unlock %s\n"),
+                                        Prog, sgr_dbname ());
+                               SYSLOG ((LOG_ERR,
+                                        "failed to unlock %s",
+                                        sgr_dbname ()));
+                               /* continue */
+                       }
+               }
+#endif
+               if (gr_unlock () == 0) {
+                       fprintf (stderr,
+                                _("%s: failed to unlock %s\n"),
+                                Prog, gr_dbname ());
+                       SYSLOG ((LOG_ERR,
+                                "failed to unlock %s",
+                                gr_dbname ()));
+                       /* continue */
+               }
        }
 
        if (is_shadow_pwd) {
@@ -1592,60 +1587,6 @@ static void close_files (void)
 #endif
 }
 
-/*
- * close_group_files - close all of the files that were opened
- *
- *     close_group_files() closes all of the files that were opened related
- *  with groups. This causes any modified entries to be written out.
- */
-static void close_group_files (void)
-{
-       if (gr_close () == 0) {
-               fprintf (stderr,
-                                       _("%s: failure while writing changes to %s\n"),
-                                       Prog, gr_dbname ());
-               SYSLOG ((LOG_ERR,
-                                       "failure while writing changes to %s",
-                                       gr_dbname ()));
-               fail_exit (E_GRP_UPDATE);
-       }
-#ifdef SHADOWGRP
-       if (is_shadow_grp) {
-               if (sgr_close () == 0) {
-                       fprintf (stderr,
-                                               _("%s: failure while writing changes to %s\n"),
-                                               Prog, sgr_dbname ());
-                       SYSLOG ((LOG_ERR,
-                                               "failure while writing changes to %s",
-                                               sgr_dbname ()));
-                       fail_exit (E_GRP_UPDATE);
-               }
-       }
-#endif
-#ifdef SHADOWGRP
-       if (is_shadow_grp) {
-               if (sgr_unlock () == 0) {
-                       fprintf (stderr,
-                                               _("%s: failed to unlock %s\n"),
-                                               Prog, sgr_dbname ());
-                       SYSLOG ((LOG_ERR,
-                                               "failed to unlock %s",
-                                               sgr_dbname ()));
-                       /* continue */
-               }
-       }
-#endif
-       if (gr_unlock () == 0) {
-               fprintf (stderr,
-                                       _("%s: failed to unlock %s\n"),
-                                       Prog, gr_dbname ());
-               SYSLOG ((LOG_ERR,
-                                       "failed to unlock %s",
-                                       gr_dbname ()));
-               /* continue */
-       }
-}
-
 /*
  * open_files - lock and open the password files
  *
@@ -1681,7 +1622,38 @@ static void open_files (void)
        }
 
        if (Gflg || lflg) {
-               open_group_files ();
+               /*
+                * Lock and open the group file. This will load all of the
+                * group entries.
+                */
+               if (gr_lock () == 0) {
+                       fprintf (stderr,
+                                _("%s: cannot lock %s; try again later.\n"),
+                                Prog, gr_dbname ());
+                       fail_exit (E_GRP_UPDATE);
+               }
+               gr_locked = true;
+               if (gr_open (O_CREAT | O_RDWR) == 0) {
+                       fprintf (stderr,
+                                _("%s: cannot open %s\n"),
+                                Prog, gr_dbname ());
+                       fail_exit (E_GRP_UPDATE);
+               }
+#ifdef SHADOWGRP
+               if (is_shadow_grp && (sgr_lock () == 0)) {
+                       fprintf (stderr,
+                                _("%s: cannot lock %s; try again later.\n"),
+                                Prog, sgr_dbname ());
+                       fail_exit (E_GRP_UPDATE);
+               }
+               sgr_locked = true;
+               if (is_shadow_grp && (sgr_open (O_CREAT | O_RDWR) == 0)) {
+                       fprintf (stderr,
+                                _("%s: cannot open %s\n"),
+                                Prog, sgr_dbname ());
+                       fail_exit (E_GRP_UPDATE);
+               }
+#endif
        }
 #ifdef ENABLE_SUBIDS
        if (vflg || Vflg) {
@@ -1717,44 +1689,6 @@ static void open_files (void)
 #endif                         /* ENABLE_SUBIDS */
 }
 
-/*
- * open_group_files - lock and open the group files
- *
- *     open_group_files() loads all of the group entries.
- */
-static void open_group_files (void)
-{
-       if (gr_lock () == 0) {
-               fprintf (stderr,
-                                       _("%s: cannot lock %s; try again later.\n"),
-                                       Prog, gr_dbname ());
-               fail_exit (E_GRP_UPDATE);
-       }
-       gr_locked = true;
-       if (gr_open (O_CREAT | O_RDWR) == 0) {
-               fprintf (stderr,
-                                       _("%s: cannot open %s\n"),
-                                       Prog, gr_dbname ());
-               fail_exit (E_GRP_UPDATE);
-       }
-
-#ifdef SHADOWGRP
-       if (is_shadow_grp && (sgr_lock () == 0)) {
-               fprintf (stderr,
-                                       _("%s: cannot lock %s; try again later.\n"),
-                                       Prog, sgr_dbname ());
-               fail_exit (E_GRP_UPDATE);
-       }
-       sgr_locked = true;
-       if (is_shadow_grp && (sgr_open (O_CREAT | O_RDWR) == 0)) {
-               fprintf (stderr,
-                                       _("%s: cannot open %s\n"),
-                                       Prog, sgr_dbname ());
-               fail_exit (E_GRP_UPDATE);
-       }
-#endif
-}
-
 /*
  * usr_update - create the user entries
  *