Avoid possible malloc(0) if plugin returns an empty groups list.

diff --git a/src/sudo.c b/src/sudo.c
index 39ee3408cdeac6776c4aba3fc05aa97f137c761c..d9a0d073024ba2c67a88443f821285adcbcb8ee4 100644 (file)
--- a/src/sudo.c
+++ b/src/sudo.c
@@ -494,19 +494,22 @@ command_info_to_details(char * const info[], struct command_details *details)
                            break;
                        cp++;
                    }
-                   details->groups = emalloc2(details->ngroups, sizeof(GETGROUPS_T));
-                   cp = info[i] + sizeof("runas_groups=") - 1;
-                   for (j = 0; j < details->ngroups;) {
-                       errno = 0;
-                       ulval = strtoul(cp, &ep, 0);
-                       if (*cp == '\0' || (*ep != ',' && *ep != '\0') ||
-                           (ulval == ULONG_MAX && errno == ERANGE)) {
-                           break;
+                   if (details->ngroups != 0) {
+                       details->groups =
+                           emalloc2(details->ngroups, sizeof(GETGROUPS_T));
+                       cp = info[i] + sizeof("runas_groups=") - 1;
+                       for (j = 0; j < details->ngroups;) {
+                           errno = 0;
+                           ulval = strtoul(cp, &ep, 0);
+                           if (*cp == '\0' || (*ep != ',' && *ep != '\0') ||
+                               (ulval == ULONG_MAX && errno == ERANGE)) {
+                               break;
+                           }
+                           details->groups[j++] = (gid_t)ulval;
+                           cp = ep + 1;
                        }
-                       details->groups[j++] = (gid_t)ulval;
-                       cp = ep + 1;
+                       details->ngroups = j;
                    }
-                   details->ngroups = j;
                    break;
                }
                if (strncmp("runas_uid=", info[i], sizeof("runas_uid=") - 1) == 0) {