Based on: https://sourceware.org/bugzilla/show_bug.cgi?id=17269 https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=patch;h=bdf1ff052a8e23d637f2c838fa5642d78fcedc33 From bdf1ff052a8e23d637f2c838fa5642d78fcedc33 Mon Sep 17 00:00:00 2001 From: Paul Pluzhnikov Date: Sun, 22 Feb 2015 12:01:47 -0800 Subject: [PATCH] Fix BZ #17269 -- _IO_wstr_overflow integer overflow --- libio/wstrops.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/libio/wstrops.c b/libio/wstrops.c index c5aae7b..fe92fd9 100644 --- a/libio/wstrops.c +++ b/libio/wstrops.c @@ -96,8 +96,11 @@ _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)); @@ -187,6 +190,9 @@ 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 -- 2.17.1