PR 60324 Unbounded stack allocations in libgfortran.

2014-11-13  Janne Blomqvist  <jb@gcc.gnu.org>

	PR libfortran/60324
	* configure: Regenerated.
	* configure.ac (AM_CFLAGS): Add Werror=vla.
	* libgfortran.h (gfc_alloca): Remove macro.
	(fc_strdup_notrim): New prototype.
	* intrinsics/access.c (access_func): Use fc_strdup rather than
	stack allocation.
	* intrinsics/chdir.c (chdir_i4_sub): Likewise.
	(chdir_i8_sub): Likewise.
	* intrinsics/chmod.c (chmod_internal): New function, move logic
	here.
	(chmod_func): Call chmod_internal.
	* intrinsics/env.c (getenv): Use fc_strdup rather than stack
	allocation.
	(get_environment_variable_i4): Likewise.
	* intrinsics/execute_command_line.c (execute_command_line):
	Likewise.
	* intrinsics/hostnm.c (hostnm_0): New function, use static buffer
	rather than VLA.
	(hostnm_i4_sub): Call hostnm_0.
	(hostnm_i8_sub): Likewise.
	(hostnm): Likewise.
	* intrinsics/link.c (link_internal): New function, use fc_strdup
	rather than stack allocation.
	(link_i4_sub): Call link_internal.
	(link_i8_sub): Likewise.
	(link_i4): Likewise.
	(link_i8): Likewise.
	* intrinsics/perror.c (perror_sub): Use fc_strdup rather than
	stack allocation.
	* intrinsics/random.c (random_seed_i4): Use static buffer rather
	than VLA, use _Static_assert to make sure it's big enough.
	* intrinsics/rename.c (rename_internal): New function, use
	fc_strdup rather than stack allocation.
	(rename_i4_sub): Call rename_internal.
	(rename_i8_sub): Likewise.
	(rename_i4): Likewise.
	(rename_i8): Likewise.
	* intrinsics/stat.c (stat_i4_sub_0): Use fc_strdup rather than
	stack allocation.
	(stat_i8_sub_0): Likewise.
	* intrinsics/symlink.c (symlnk_internal): New function, use
	fc_strdup rather than stack allocation.
	(symlnk_i4_sub): Call symlnk_internal.
	(symlnk_i8_sub): Likewise.
	(symlnk_i4): Likewise.
	(symlnk_i8): Likewise.
	* intrinsics/system.c (system_sub): Use fc_strdup rather than
	stack allocation.
	* intrinsics/unlink.c (unlink_i4_sub): Likewise.
	* io/file_pos.c (READ_CHUNK): Make it a macro rather than variable.
	* io/list_read.c (nml_get_obj_data): Use fixed stack buffer, fall
	back to xmalloc/free for large sizes.
	* io/read.c (read_f): Likewise.
	* io/transfer.c (MAX_READ): Make it a macro rather than variable.
	(WRITE_CHUNK): Likewise.
	* io/write_float.def (write_float): Use fixed stack buffer, fall
	back to xmalloc/free for large sizes.
	* runtime/string.c (fc_strdup_notrim): New function.

From-SVN: r217480

1 files changed, 28 insertions, 47 deletions

diff --git a/libgfortran/intrinsics/link.c b/libgfortran/intrinsics/link.c
index 2018c62..c6084a1 100644
--- a/libgfortran/intrinsics/link.c
+++ b/libgfortran/intrinsics/link.c
@@ -2,7 +2,7 @@
    Copyright (C) 2005-2014 Free Software Foundation, Inc.
    Contributed by François-Xavier Coudert <coudert@clipper.ens.fr>
 
-This file is part of the GNU Fortran 95 runtime library (libgfortran).
+This file is part of the GNU Fortran runtime library (libgfortran).
 
 Libgfortran is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public
@@ -37,36 +37,39 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    INTEGER, INTENT(OUT), OPTIONAL :: STATUS  */
 
 #ifdef HAVE_LINK
-extern void link_i4_sub (char *, char *, GFC_INTEGER_4 *, gfc_charlen_type,
-	                 gfc_charlen_type);
-iexport_proto(link_i4_sub);
 
-void
-link_i4_sub (char *path1, char *path2, GFC_INTEGER_4 *status,
-             gfc_charlen_type path1_len, gfc_charlen_type path2_len)
+static int
+link_internal (char *path1, char *path2, gfc_charlen_type path1_len,
+	       gfc_charlen_type path2_len)
 {
   int val;
   char *str1, *str2;
 
-  /* Trim trailing spaces from paths.  */
-  while (path1_len > 0 && path1[path1_len - 1] == ' ')
-    path1_len--;
-  while (path2_len > 0 && path2[path2_len - 1] == ' ')
-    path2_len--;
-
   /* Make a null terminated copy of the strings.  */
-  str1 = gfc_alloca (path1_len + 1);
-  memcpy (str1, path1, path1_len);
-  str1[path1_len] = '\0';
-
-  str2 = gfc_alloca (path2_len + 1);
-  memcpy (str2, path2, path2_len);
-  str2[path2_len] = '\0';
+  str1 = fc_strdup (path1, path1_len);
+  str2 = fc_strdup (path2, path2_len);
 
   val = link (str1, str2);
 
+  free (str1);
+  free (str2);
+
+  return ((val == 0) ? 0 : errno);
+}
+
+
+extern void link_i4_sub (char *, char *, GFC_INTEGER_4 *, gfc_charlen_type,
+	                 gfc_charlen_type);
+iexport_proto(link_i4_sub);
+
+void
+link_i4_sub (char *path1, char *path2, GFC_INTEGER_4 *status,
+             gfc_charlen_type path1_len, gfc_charlen_type path2_len)
+{
+  int val = link_internal (path1, path2, path1_len, path2_len);
+
   if (status != NULL)
-    *status = (val == 0) ? 0 : errno;
+    *status = val;
 }
 iexport(link_i4_sub);
 
@@ -78,28 +81,10 @@ void
 link_i8_sub (char *path1, char *path2, GFC_INTEGER_8 *status,
              gfc_charlen_type path1_len, gfc_charlen_type path2_len)
 {
-  int val;
-  char *str1, *str2;
-
-  /* Trim trailing spaces from paths.  */
-  while (path1_len > 0 && path1[path1_len - 1] == ' ')
-    path1_len--;
-  while (path2_len > 0 && path2[path2_len - 1] == ' ')
-    path2_len--;
-
-  /* Make a null terminated copy of the strings.  */
-  str1 = gfc_alloca (path1_len + 1);
-  memcpy (str1, path1, path1_len);
-  str1[path1_len] = '\0';
-
-  str2 = gfc_alloca (path2_len + 1);
-  memcpy (str2, path2, path2_len);
-  str2[path2_len] = '\0';
-
-  val = link (str1, str2);
+  int val = link_internal (path1, path2, path1_len, path2_len);
 
   if (status != NULL)
-    *status = (val == 0) ? 0 : errno;
+    *status = val;
 }
 iexport(link_i8_sub);
 
@@ -111,9 +96,7 @@ GFC_INTEGER_4
 link_i4 (char *path1, char *path2, gfc_charlen_type path1_len,
          gfc_charlen_type path2_len)
 {
-  GFC_INTEGER_4 val;
-  link_i4_sub (path1, path2, &val, path1_len, path2_len);
-  return val;
+  return link_internal (path1, path2, path1_len, path2_len);
 }
 
 extern GFC_INTEGER_8 link_i8 (char *, char *, gfc_charlen_type,
@@ -124,8 +107,6 @@ GFC_INTEGER_8
 link_i8 (char *path1, char *path2, gfc_charlen_type path1_len,
 	 gfc_charlen_type path2_len)
 {
-  GFC_INTEGER_8 val;
-  link_i8_sub (path1, path2, &val, path1_len, path2_len);
-  return val;
+  return link_internal (path1, path2, path1_len, path2_len);
 }
 #endif