2.5-18.1

[jlayton/glibc.git] / grp / initgroups.c

diff --git a/grp/initgroups.c b/grp/initgroups.c
index d052cf48f7b9bdd4861c7f89e744785bf1bb42a5..2e489463dfe96ebab9e31568e8df10a23cf7aaac 100644 (file)
--- a/grp/initgroups.c
+++ b/grp/initgroups.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1989,91,93,1996-2003, 2004  Free Software Foundation, Inc.
+/* Copyright (C) 1989,91,93,1996-2005,2006 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -17,6 +17,7 @@
    02111-1307 USA.  */
 
 #include <alloca.h>
+#include <assert.h>
 #include <errno.h>
 #include <grp.h>
 #include <limits.h>
@@ -73,6 +74,8 @@ internal_getgrouplist (const char *user, gid_t group, long int *size,
   /* Start is one, because we have the first group as parameter.  */
   long int start = 1;
 
+  /* Never store more than the starting *SIZE number of elements.  */
+  assert (*size > 0);
   (*groupsp)[0] = group;
 
   if (__nss_group_database != NULL)
@@ -140,11 +143,9 @@ internal_getgrouplist (const char *user, gid_t group, long int *size,
 int
 getgrouplist (const char *user, gid_t group, gid_t *groups, int *ngroups)
 {
-  gid_t *newgroups;
   long int size = MAX (1, *ngroups);
-  int result;
 
-  newgroups = (gid_t *) malloc ((size + 1) * sizeof (gid_t));
+  gid_t *newgroups = (gid_t *) malloc (size * sizeof (gid_t));
   if (__builtin_expect (newgroups == NULL, 0))
     /* No more memory.  */
     // XXX This is wrong.  The user provided memory, we have to use
@@ -153,20 +154,16 @@ getgrouplist (const char *user, gid_t group, gid_t *groups, int *ngroups)
     // XXX too small.  For initgroups a flag could say: increase size.
     return -1;
 
-  result = internal_getgrouplist (user, group, &size, &newgroups, -1);
-
-  memcpy (groups, newgroups, MIN (*ngroups, result) * sizeof (gid_t));
+  int total = internal_getgrouplist (user, group, &size, &newgroups, -1);
 
-  if (result > *ngroups)
-    {
-      *ngroups = result;
-      result = -1;
-    }
-  else
-    *ngroups = result;
+  memcpy (groups, newgroups, MIN (*ngroups, total) * sizeof (gid_t));
 
   free (newgroups);
-  return result;
+
+  int retval = total > *ngroups ? -1 : total;
+  *ngroups = total;
+
+  return retval;
 }
 
 static_link_warning (getgrouplist)