iconv_open: Fix heap corruption on gconv_init failure [BZ #22026]

Also mangle the __end_fct function pointer on the error handling
path.

1 files changed, 49 insertions, 0 deletions

diff --git a/iconv/tst-gconv-init-failure-mod.c b/iconv/tst-gconv-init-failure-mod.c
new file mode 100644
index 0000000000..7e7d1b9a15
--- /dev/null
+++ b/iconv/tst-gconv-init-failure-mod.c
@@ -0,0 +1,49 @@
+/* Test gconv module for tst-gconv-init-failure.
+   Copyright (C) 2017 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <gconv.h>
+#include <support/check.h>
+#include <support/support.h>
+
+int
+gconv (struct __gconv_step *step,
+       struct __gconv_step_data *data,
+       const unsigned char **inptrp,
+       const unsigned char *inend,
+       unsigned char **outbufstart, size_t *irreversible,
+       int do_flush, int consume_incomplete)
+{
+  FAIL_EXIT1 ("gconv called");
+  return __GCONV_INTERNAL_ERROR;
+}
+
+int
+gconv_init (struct __gconv_step *ignored)
+{
+  write_message ("info: gconv_init called, returning error\n");
+  errno = ENOMEM;
+  return __GCONV_NOMEM;
+}
+
+int
+gconv_end (struct __gconv_step *ignored)
+{
+  FAIL_EXIT1 ("gconv_end called");
+  return __GCONV_INTERNAL_ERROR;
+}