useradd: avoid generating an empty subid range

useradd generates an empty subid range when adding a new user. This is
caused because there are two variables, one local and the other one
global, that have a very similar name and they are used indistinctly in
the code. The local variable loads the SUB_*ID_COUNT configuration from
the login.defs file, while the global variable, which holds a value of
0, is used to generate the subid range. Causing the empty subid range
problem.

I've merged the two variables in the local one and removed the global
variable. I prefer to do it this way to reduce the scope of it but I'm
open to doing it the other way round.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1990653

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

diff --git a/src/useradd.c b/src/useradd.c
index baeffb35af01179b1d1ee4e012b5f7f05b6fd62d..9abeea6e4c676a256c87bf06248fcd2b3eda63bc 100644 (file)
--- a/src/useradd.c
+++ b/src/useradd.c
@@ -142,9 +142,7 @@ static bool is_sub_gid = false;
 static bool sub_uid_locked = false;
 static bool sub_gid_locked = false;
 static uid_t sub_uid_start;    /* New subordinate uid range */
-static unsigned long sub_uid_count;
 static gid_t sub_gid_start;    /* New subordinate gid range */
-static unsigned long sub_gid_count;
 #endif                         /* ENABLE_SUBIDS */
 static bool pw_locked = false;
 static bool gr_locked = false;
@@ -234,7 +232,7 @@ static void open_shadow (void);
 static void faillog_reset (uid_t);
 static void lastlog_reset (uid_t);
 static void tallylog_reset (const char *);
-static void usr_update (void);
+static void usr_update (unsigned long subuid_count, unsigned long subgid_count);
 static void create_home (void);
 static void create_mail (void);
 static void check_uid_range(int rflg, uid_t user_id);
@@ -2092,7 +2090,7 @@ static void tallylog_reset (const char *user_name)
  *     usr_update() creates the password file entries for this user
  *     and will update the group entries if required.
  */
-static void usr_update (void)
+static void usr_update (unsigned long subuid_count, unsigned long subgid_count)
 {
        struct passwd pwent;
        struct spwd spent;
@@ -2155,14 +2153,14 @@ static void usr_update (void)
        }
 #ifdef ENABLE_SUBIDS
        if (is_sub_uid &&
-           (sub_uid_add(user_name, sub_uid_start, sub_uid_count) == 0)) {
+           (sub_uid_add(user_name, sub_uid_start, subuid_count) == 0)) {
                fprintf (stderr,
                         _("%s: failed to prepare the new %s entry\n"),
                         Prog, sub_uid_dbname ());
                fail_exit (E_SUB_UID_UPDATE);
        }
        if (is_sub_gid &&
-           (sub_gid_add(user_name, sub_gid_start, sub_gid_count) == 0)) {
+           (sub_gid_add(user_name, sub_gid_start, subgid_count) == 0)) {
                fprintf (stderr,
                         _("%s: failed to prepare the new %s entry\n"),
                         Prog, sub_uid_dbname ());
@@ -2624,16 +2622,16 @@ int main (int argc, char **argv)
        }
 
 #ifdef ENABLE_SUBIDS
-       if (is_sub_uid && sub_uid_count != 0) {
-               if (find_new_sub_uids(&sub_uid_start, &sub_uid_count) < 0) {
+       if (is_sub_uid && subuid_count != 0) {
+               if (find_new_sub_uids(&sub_uid_start, &subuid_count) < 0) {
                        fprintf (stderr,
                                 _("%s: can't create subordinate user IDs\n"),
                                 Prog);
                        fail_exit(E_SUB_UID_UPDATE);
                }
        }
-       if (is_sub_gid && sub_gid_count != 0) {
-               if (find_new_sub_gids(&sub_gid_start, &sub_gid_count) < 0) {
+       if (is_sub_gid && subgid_count != 0) {
+               if (find_new_sub_gids(&sub_gid_start, &subgid_count) < 0) {
                        fprintf (stderr,
                                 _("%s: can't create subordinate group IDs\n"),
                                 Prog);
@@ -2642,7 +2640,7 @@ int main (int argc, char **argv)
        }
 #endif                         /* ENABLE_SUBIDS */
 
-       usr_update ();
+       usr_update (subuid_count, subgid_count);
 
        if (mflg) {
                create_home ();