blob: 77e82b16741a8ed5cf2d6025bf80f62b6f77858d [file] [log] [blame]
Brad Bishop1a4b7ee2018-12-16 17:11:34 -08001From e91600a7aae3bafbefbe13abf771e61badd16286 Mon Sep 17 00:00:00 2001
2From: Changqing Li <changqing.li@windriver.com>
3Date: Tue, 16 Oct 2018 14:26:11 +0800
4Subject: [PATCH] vasnprintf: Fix heap memory overrun bug.
5
6Reported by Ben Pfaff <blp@cs.stanford.edu> in
7<https://lists.gnu.org/archive/html/bug-gnulib/2018-09/msg00107.html>.
8
9* lib/vasnprintf.c (convert_to_decimal): Allocate one more byte of
10memory.
11* tests/test-vasnprintf.c (test_function): Add another test.
12
13Upstream-Status: Backport [http://git.savannah.gnu.org/gitweb/?p=gnulib.git;
14a=commitdiff;h=278b4175c9d7dd47c1a3071554aac02add3b3c35]
15
16CVE: CVE-2018-17942
17
18Signed-off-by: Changqing Li <changqing.li@windriver.com>
19---
20 ChangeLog | 8 ++++++++
21 lib/vasnprintf.c | 4 +++-
22 tests/test-vasnprintf.c | 19 ++++++++++++++++++-
23 3 files changed, 29 insertions(+), 2 deletions(-)
24
25diff --git a/ChangeLog b/ChangeLog
26index 9864353..5ff76a3 100644
27--- a/ChangeLog
28+++ b/ChangeLog
29@@ -1,3 +1,11 @@
30+2018-09-23 Bruno Haible <bruno@clisp.org>
31+ vasnprintf: Fix heap memory overrun bug.
32+ Reported by Ben Pfaff <blp@cs.stanford.edu> in
33+ <https://lists.gnu.org/archive/html/bug-gnulib/2018-09/msg00107.html>.
34+ * lib/vasnprintf.c (convert_to_decimal): Allocate one more byte of
35+ memory.
36+ * tests/test-vasnprintf.c (test_function): Add another test.
37+
38 2017-08-21 Paul Eggert <eggert@cs.ucla.edu>
39
40 vc-list-files: port to Solaris 10
41diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c
42index 2e4eb19..45de49f 100644
43--- a/lib/vasnprintf.c
44+++ b/lib/vasnprintf.c
45@@ -860,7 +860,9 @@ convert_to_decimal (mpn_t a, size_t extra_zeroes)
46 size_t a_len = a.nlimbs;
47 /* 0.03345 is slightly larger than log(2)/(9*log(10)). */
48 size_t c_len = 9 * ((size_t)(a_len * (GMP_LIMB_BITS * 0.03345f)) + 1);
49- char *c_ptr = (char *) malloc (xsum (c_len, extra_zeroes));
50+ /* We need extra_zeroes bytes for zeroes, followed by c_len bytes for the
51+ digits of a, followed by 1 byte for the terminating NUL. */
52+ char *c_ptr = (char *) malloc (xsum (xsum (extra_zeroes, c_len), 1));
53 if (c_ptr != NULL)
54 {
55 char *d_ptr = c_ptr;
56diff --git a/tests/test-vasnprintf.c b/tests/test-vasnprintf.c
57index 2dd869f..ff68d5c 100644
58--- a/tests/test-vasnprintf.c
59+++ b/tests/test-vasnprintf.c
60@@ -53,7 +53,24 @@ test_function (char * (*my_asnprintf) (char *, size_t *, const char *, ...))
61 ASSERT (result != NULL);
62 ASSERT (strcmp (result, "12345") == 0);
63 ASSERT (length == 5);
64- if (size < 6)
65+ if (size < 5 + 1)
66+ ASSERT (result != buf);
67+ ASSERT (memcmp (buf + size, &"DEADBEEF"[size], 8 - size) == 0);
68+ if (result != buf)
69+ free (result);
70+ }
71+ /* Note: This test assumes IEEE 754 representation of 'double' floats. */
72+ for (size = 0; size <= 8; size++)
73+ {
74+ size_t length;
75+ char *result;
76+ memcpy (buf, "DEADBEEF", 8);
77+ length = size;
78+ result = my_asnprintf (buf, &length, "%2.0f", 1.6314159265358979e+125);
79+ ASSERT (result != NULL);
80+ ASSERT (strcmp (result, "163141592653589790215729350939528493057529598899734151772468186268423257777068536614838678161083520756952076273094236944990208") == 0);
81+ ASSERT (length == 126);
82+ if (size < 126 + 1)
83 ASSERT (result != buf);
84 ASSERT (memcmp (buf + size, &"DEADBEEF"[size], 8 - size) == 0);
85 if (result != buf)
86--
872.7.4
88