(init_user_info): Allocate buf[] with xmalloc using the size needed by

GetTokenInformation.
(w32_system_process_attributes): Check return values of all system APIs.

2 files changed, 154 insertions, 81 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index e25a09ae453..1131367262f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,10 @@
 2008-08-30  Eli Zaretskii  <eliz@gnu.org>
 
+        * w32.c (init_user_info): Allocate buf[] with xmalloc using the size
+        needed by GetTokenInformation.
+        (w32_system_process_attributes): Check return values of all system
+        APIs.
+
         * msdos.c (IT_display_cursor): Write "CURSOR ON/OFF" to termscript
         only when the state changes.
         (IT_update_begin, IT_update_end): Add termscript trace.
diff --git a/src/w32.c b/src/w32.c
index c7af7f06340..1032ac57af6 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -907,20 +907,37 @@ init_user_info ()
      primary group sid from the process token). */
 
   char         uname[UNLEN+1], gname[GNLEN+1], domain[1025];
-  DWORD        ulength = sizeof (uname), dlength = sizeof (domain), trash;
+  DWORD        ulength = sizeof (uname), dlength = sizeof (domain), needed;
   DWORD        glength = sizeof (gname);
   HANDLE       token = NULL;
   SID_NAME_USE user_type;
-  unsigned char buf[1024];
+  unsigned char *buf = NULL;
+  DWORD        blen = 0;
   TOKEN_USER   user_token;
   TOKEN_PRIMARY_GROUP group_token;
+  BOOL         result;
 
-  if (open_process_token (GetCurrentProcess (), TOKEN_QUERY, &token)
-      && get_token_information (token, TokenUser,
-                                (PVOID)buf, sizeof (buf), &trash)
-      && (memcpy (&user_token, buf, sizeof (user_token)),
-          lookup_account_sid (NULL, user_token.User.Sid, uname, &ulength,
-                              domain, &dlength, &user_type)))
+  result = open_process_token (GetCurrentProcess (), TOKEN_QUERY, &token);
+  if (result)
+    {
+      result = get_token_information (token, TokenUser, NULL, 0, &blen);
+      if (!result && GetLastError () == ERROR_INSUFFICIENT_BUFFER)
+        {
+          buf = xmalloc (blen);
+          result = get_token_information (token, TokenUser,
+                                          (LPVOID)buf, blen, &needed);
+          if (result)
+            {
+              memcpy (&user_token, buf, sizeof (user_token));
+              result = lookup_account_sid (NULL, user_token.User.Sid,
+                                           uname, &ulength,
+                                           domain, &dlength, &user_type);
+            }
+        }
+      else
+        result = FALSE;
+    }
+  if (result)
     {
       strcpy (dflt_passwd.pw_name, uname);
       /* Determine a reasonable uid value.  */
@@ -936,12 +953,22 @@ init_user_info ()
           dflt_passwd.pw_uid = get_rid (user_token.User.Sid);
 
           /* Get group id and name.  */
-          if (get_token_information (token, TokenPrimaryGroup,
-                                     (PVOID)buf, sizeof (buf), &trash))
+          result = get_token_information (token, TokenPrimaryGroup,
+                                          (LPVOID)buf, blen, &needed);
+          if (!result && GetLastError () == ERROR_INSUFFICIENT_BUFFER)
+            {
+              buf = xrealloc (buf, blen = needed);
+              result = get_token_information (token, TokenPrimaryGroup,
+                                              (LPVOID)buf, blen, &needed);
+            }
+          if (result)
             {
               memcpy (&group_token, buf, sizeof (group_token));
               dflt_passwd.pw_gid = get_rid (group_token.PrimaryGroup);
               dlength = sizeof (domain);
+              /* If we can get at the real Primary Group name, use that.
+                 Otherwise, the default group name was already set to
+                 "None" in globals_of_w32.  */
               if (lookup_account_sid (NULL, group_token.PrimaryGroup,
                                       gname, &glength, NULL, &dlength,
                                       &user_type))
@@ -952,7 +979,7 @@ init_user_info ()
         }
     }
   /* If security calls are not supported (presumably because we
-     are running under Windows 95), fallback to this. */
+     are running under Windows 9X), fallback to this: */
   else if (GetUserName (uname, &ulength))
     {
       strcpy (dflt_passwd.pw_name, uname);
@@ -980,6 +1007,7 @@ init_user_info ()
   strcpy (dflt_passwd.pw_dir, getenv ("HOME"));
   strcpy (dflt_passwd.pw_shell, getenv ("SHELL"));
 
+  xfree (buf);
   if (token)
     CloseHandle (token);
 }
@@ -3810,11 +3838,12 @@ w32_system_process_attributes (pid)
   DWORD proc_id;
   int found_proc = 0;
   char uname[UNLEN+1], gname[GNLEN+1], domain[1025];
-  DWORD ulength = sizeof (uname), dlength = sizeof (domain), trash;
+  DWORD ulength = sizeof (uname), dlength = sizeof (domain), needed;
   DWORD glength = sizeof (gname);
   HANDLE token = NULL;
   SID_NAME_USE user_type;
-  unsigned char buf[1024];
+  unsigned char *buf = NULL;
+  DWORD blen = 0;
   TOKEN_USER user_token;
   TOKEN_PRIMARY_GROUP group_token;
   int euid;
@@ -3828,6 +3857,7 @@ w32_system_process_attributes (pid)
   double totphys = 0.0;
   Lisp_Object ctime, stime, utime, etime;
   double pcpu;
+  BOOL result = FALSE;
 
   CHECK_NUMBER_OR_FLOAT (pid);
   proc_id = FLOATP (pid) ? XFLOAT_DATA (pid) : XINT (pid);
@@ -3898,87 +3928,125 @@ w32_system_process_attributes (pid)
           revert_to_self ();
         }
     }
-  if (h_proc
-      && open_process_token (h_proc, TOKEN_QUERY, &token)
-      && get_token_information (token, TokenUser,
-                                (PVOID)buf, sizeof (buf), &trash))
+  if (h_proc)
     {
-      memcpy (&user_token, buf, sizeof (user_token));
-      if (w32_cached_id (user_token.User.Sid, &euid, uname))
-        ulength = strlen (uname);
-      else
-        {
-          lookup_account_sid (NULL, user_token.User.Sid, uname, &ulength,
-                              domain, &dlength, &user_type);
-          euid = get_rid (user_token.User.Sid);
-          w32_add_to_cache (user_token.User.Sid, euid, uname);
-        }
-      /* Determine a reasonable euid and gid values.  */
-      if (xstrcasecmp ("administrator", uname) == 0)
+      result = open_process_token (h_proc, TOKEN_QUERY, &token);
+      if (result)
         {
-          euid = 500;   /* well-known Administrator uid */
-          egid = 513;   /* well-known None gid */
+          result = get_token_information (token, TokenUser, NULL, 0, &blen);
+          if (!result && GetLastError () == ERROR_INSUFFICIENT_BUFFER)
+            {
+              buf = xmalloc (blen);
+              result = get_token_information (token, TokenUser,
+                                              (LPVOID)buf, blen, &needed);
+              if (result)
+                {
+                  memcpy (&user_token, buf, sizeof (user_token));
+                  if (!w32_cached_id (user_token.User.Sid, &euid, uname))
+                    {
+                      euid = get_rid (user_token.User.Sid);
+                      result = lookup_account_sid (NULL, user_token.User.Sid,
+                                                   uname, &ulength,
+                                                   domain, &dlength,
+                                                   &user_type);
+                      if (result)
+                        w32_add_to_cache (user_token.User.Sid, euid, uname);
+                      else
+                        {
+                          strcpy (uname, "unknown");
+                          result = TRUE;
+                        }
+                    }
+                  ulength = strlen (uname);
+                }
+            }
         }
-      else
+      if (result)
         {
-          /* Get group id and name.  */
-          if (get_token_information (token, TokenPrimaryGroup,
-                                     (PVOID)buf, sizeof (buf), &trash))
+          /* Determine a reasonable euid and gid values.  */
+          if (xstrcasecmp ("administrator", uname) == 0)
             {
-              memcpy (&group_token, buf, sizeof (group_token));
-              if (w32_cached_id (group_token.PrimaryGroup, &egid, gname))
-                glength = strlen (gname);
-              else
+              euid = 500;       /* well-known Administrator uid */
+              egid = 513;       /* well-known None gid */
+            }
+          else
+            {
+              /* Get group id and name.  */
+              result = get_token_information (token, TokenPrimaryGroup,
+                                              (LPVOID)buf, blen, &needed);
+              if (!result && GetLastError () == ERROR_INSUFFICIENT_BUFFER)
                 {
-                  dlength = sizeof (domain);
-                  lookup_account_sid (NULL, group_token.PrimaryGroup,
-                                      gname, &glength, NULL, &dlength,
-                                      &user_type);
-                  egid = get_rid (group_token.PrimaryGroup);
-                  w32_add_to_cache (group_token.PrimaryGroup, egid, gname);
+                  buf = xrealloc (buf, blen = needed);
+                  result = get_token_information (token, TokenPrimaryGroup,
+                                                  (LPVOID)buf, blen, &needed);
+                }
+              if (result)
+                {
+                  memcpy (&group_token, buf, sizeof (group_token));
+                  if (!w32_cached_id (group_token.PrimaryGroup, &egid, gname))
+                    {
+                      egid = get_rid (group_token.PrimaryGroup);
+                      dlength = sizeof (domain);
+                      result =
+                        lookup_account_sid (NULL, group_token.PrimaryGroup,
+                                            gname, &glength, NULL, &dlength,
+                                            &user_type);
+                      if (result)
+                        w32_add_to_cache (group_token.PrimaryGroup,
+                                          egid, gname);
+                      else
+                        {
+                          strcpy (gname, "None");
+                          result = TRUE;
+                        }
+                    }
+                  glength = strlen (gname);
                 }
             }
-          else
-            egid = euid;
         }
+      if (buf)
+        xfree (buf);
     }
-  else if (!is_windows_9x ())
-    {
-      /* We couldn't open the process token, presumably because of
-         insufficient access rights.  Assume this process is run by
-         the system.  */
-      strcpy (uname, "SYSTEM");
-      strcpy (gname, "None");
-      euid = 18;        /* SYSTEM */
-      egid = 513;       /* None */
-      glength = strlen (gname);
-      ulength = strlen (uname);
-    }
-  /* If we are running under Windows 9X, where security calls are not
-     supported, we assume all processes are run by the current
-     user.  */
-  else if (GetUserName (uname, &ulength))
+  if (!result)
     {
-      if (xstrcasecmp ("administrator", uname) == 0)
-        euid = 0;
+      if (!is_windows_9x ())
+        {
+          /* We couldn't open the process token, presumably because of
+             insufficient access rights.  Assume this process is run
+             by the system.  */
+          strcpy (uname, "SYSTEM");
+          strcpy (gname, "None");
+          euid = 18;    /* SYSTEM */
+          egid = 513;   /* None */
+          glength = strlen (gname);
+          ulength = strlen (uname);
+        }
+      /* If we are running under Windows 9X, where security calls are
+         not supported, we assume all processes are run by the current
+         user.  */
+      else if (GetUserName (uname, &ulength))
+        {
+          if (xstrcasecmp ("administrator", uname) == 0)
+            euid = 0;
+          else
+            euid = 123;
+          egid = euid;
+          strcpy (gname, "None");
+          glength = strlen (gname);
+          ulength = strlen (uname);
+        }
       else
-        euid = 123;
-      egid = euid;
-      strcpy (gname, "None");
-      glength = strlen (gname);
-      ulength = strlen (uname);
-    }
-  else
-    {
-      euid = 123;
-      egid = 123;
-      strcpy (uname, "administrator");
-      ulength = strlen (uname);
-      strcpy (gname, "None");
-      glength = strlen (gname);
+        {
+          euid = 123;
+          egid = 123;
+          strcpy (uname, "administrator");
+          ulength = strlen (uname);
+          strcpy (gname, "None");
+          glength = strlen (gname);
+        }
+      if (token)
+        CloseHandle (token);
     }
-  if (token)
-    CloseHandle (token);
 
   attrs = Fcons (Fcons (Qeuid, make_fixnum_or_float (euid)), attrs);
   tem = make_unibyte_string (uname, ulength);