From: Bruno Haible <bruno@clisp.org>
Date: Tue, 30 Mar 2021 02:44:30 +0000 (+0900)
Subject: Subject: [PATCH] vasnprintf: Fix heap memory overrun bug.
X-Git-Tag: submit/tizen_6.0_base/20210330.060858^0
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e12519bbf320b2cdf49ccb95f01e6debcac3660a;p=platform%2Fupstream%2Fcpio.git

Subject: [PATCH] vasnprintf: Fix heap memory overrun bug.

Reported by Ben Pfaff <blp@cs.stanford.edu> in
<https://lists.gnu.org/archive/html/bug-gnulib/2018-09/msg00107.html>.

* lib/vasnprintf.c (convert_to_decimal): Allocate one more byte of
memory.
* tests/test-vasnprintf.c (test_function): Add another test.

Change-Id: I06fab298f8c383605db52742959e60822f7f143e
Signed-off-by: JinWang An <jinwang.an@samsung.com>
---

diff --git a/gnu/vasnprintf.c b/gnu/vasnprintf.c
index 3fbba53..35d3129 100644
--- a/gnu/vasnprintf.c
+++ b/gnu/vasnprintf.c
@@ -808,7 +808,9 @@ convert_to_decimal (mpn_t a, size_t extra_zeroes)
   size_t a_len = a.nlimbs;
   /* 0.03345 is slightly larger than log(2)/(9*log(10)).  */
   size_t c_len = 9 * ((size_t)(a_len * (GMP_LIMB_BITS * 0.03345f)) + 1);
-  char *c_ptr = (char *) malloc (xsum (c_len, extra_zeroes));
+  /* We need extra_zeroes bytes for zeroes, followed by c_len bytes for the
+     digits of a, followed by 1 byte for the terminating NUL.  */
+  char *c_ptr = (char *) malloc (xsum (xsum (extra_zeroes, c_len), 1));
   if (c_ptr != NULL)
     {
       char *d_ptr = c_ptr;