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, 16 insertions, 15 deletions

diff --git a/libgfortran/intrinsics/chmod.c b/libgfortran/intrinsics/chmod.c
index acef433d..c42fa8c 100644
--- a/libgfortran/intrinsics/chmod.c
+++ b/libgfortran/intrinsics/chmod.c
@@ -61,14 +61,10 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    A return value of 0 indicates success, -1 an error of chmod() while 1
    indicates a mode parsing error.  */
 
-extern int chmod_func (char *, char *, gfc_charlen_type, gfc_charlen_type);
-export_proto(chmod_func);
 
-int
-chmod_func (char *name, char *mode, gfc_charlen_type name_len,
-	    gfc_charlen_type mode_len)
+static int
+chmod_internal (char *file, char *mode, gfc_charlen_type mode_len)
 {
-  char * file;
   int i;
   bool ugo[3];
   bool rwxXstugo[9];
@@ -80,15 +76,6 @@ chmod_func (char *name, char *mode, gfc_charlen_type name_len,
   mode_t mode_mask, file_mode, new_mode;
   struct stat stat_buf;
 
-  /* Trim trailing spaces of the file name.  */
-  while (name_len > 0 && name[name_len - 1] == ' ')
-    name_len--;
-
-  /* Make a null terminated copy of the file name.  */
-  file = gfc_alloca (name_len + 1);
-  memcpy (file, name, name_len);
-  file[name_len] = '\0';
-
   if (mode_len == 0)
     return 1;
 
@@ -496,6 +483,20 @@ clause_done:
 }
 
 
+extern int chmod_func (char *, char *, gfc_charlen_type, gfc_charlen_type);
+export_proto(chmod_func);
+
+int
+chmod_func (char *name, char *mode, gfc_charlen_type name_len,
+	    gfc_charlen_type mode_len)
+{
+  char *cname = fc_strdup (name, name_len);
+  int ret = chmod_internal (cname, mode, mode_len);
+  free (cname);
+  return ret;
+}
+
+
 extern void chmod_i4_sub (char *, char *, GFC_INTEGER_4 *,
 			  gfc_charlen_type, gfc_charlen_type);
 export_proto(chmod_i4_sub);