Fix BZ #17269 -- _IO_wstr_overflow integer overflow

(cherry picked from commit bdf1ff052a8e23d637f2c838fa5642d78fcedc33)

Conflicts:
	NEWS

diff --git a/ChangeLog b/ChangeLog
index 79a59d59cd787b6b0b4c269b8879ca902a859f8e..435d1899e216150d895695ddc126891d59c7840e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2015-12-30  Paul Pluzhnikov  <ppluzhnikov@google.com>
+
+       [BZ #17269]
+       * libio/wstrops.c (_IO_wstr_overflow): Guard against integer overflow
+       (enlarge_userbuf): Likewise.
+
 2015-12-30  Andreas Schwab  <schwab@suse.de>
 
        [BZ #18032]

diff --git a/NEWS b/NEWS
index 3ae421139dd578ab6c360b8701886ccda6d39eea..0196d047aade05037adc6631eb29ee942f56ccaa 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -10,7 +10,7 @@ Version 2.18.1
 * The following bugs are resolved with this release:
 
   15073, 15128, 15909, 15996, 16150, 16169, 16387, 16510, 16885, 16916,
-  16943, 16958, 18032, 18928, 19018.
+  16943, 16958, 17269, 18032, 18928, 19018.
 
 * The LD_POINTER_GUARD environment variable can no longer be used to
   disable the pointer guard feature.  It is always enabled.

diff --git a/libio/wstrops.c b/libio/wstrops.c
index 828393081e297d04dc6eb98c8ef0ec1751841368..19193e4826d2287a80a90b5cc0a68c34d2d89e87 100644 (file)
--- a/libio/wstrops.c
+++ b/libio/wstrops.c
@@ -95,8 +95,11 @@ _IO_wstr_overflow (fp, c)
          wchar_t *old_buf = fp->_wide_data->_IO_buf_base;
          size_t old_wblen = _IO_wblen (fp);
          _IO_size_t new_size = 2 * old_wblen + 100;
-         if (new_size < old_wblen)
+
+         if (__glibc_unlikely (new_size < old_wblen)
+             || __glibc_unlikely (new_size > SIZE_MAX / sizeof (wchar_t)))
            return EOF;
+
          new_buf
            = (wchar_t *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (new_size
                                                                        * sizeof (wchar_t));
@@ -186,6 +189,9 @@ enlarge_userbuf (_IO_FILE *fp, _IO_off64_t offset, int reading)
     return 1;
 
   _IO_size_t newsize = offset + 100;
+  if (__glibc_unlikely (newsize > SIZE_MAX / sizeof (wchar_t)))
+    return 1;
+
   wchar_t *oldbuf = wd->_IO_buf_base;
   wchar_t *newbuf
     = (wchar_t *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (newsize