| From e91600a7aae3bafbefbe13abf771e61badd16286 Mon Sep 17 00:00:00 2001 |
| From: Changqing Li <changqing.li@windriver.com> |
| Date: Tue, 16 Oct 2018 14:26:11 +0800 |
| 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. |
| |
| Upstream-Status: Backport [http://git.savannah.gnu.org/gitweb/?p=gnulib.git; |
| a=commitdiff;h=278b4175c9d7dd47c1a3071554aac02add3b3c35] |
| |
| CVE: CVE-2018-17942 |
| |
| Signed-off-by: Changqing Li <changqing.li@windriver.com> |
| --- |
| ChangeLog | 8 ++++++++ |
| lib/vasnprintf.c | 4 +++- |
| tests/test-vasnprintf.c | 19 ++++++++++++++++++- |
| 3 files changed, 29 insertions(+), 2 deletions(-) |
| |
| diff --git a/ChangeLog b/ChangeLog |
| index 9864353..5ff76a3 100644 |
| --- a/ChangeLog |
| +++ b/ChangeLog |
| @@ -1,3 +1,11 @@ |
| +2018-09-23 Bruno Haible <bruno@clisp.org> |
| + 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. |
| + |
| 2017-08-21 Paul Eggert <eggert@cs.ucla.edu> |
| |
| vc-list-files: port to Solaris 10 |
| diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c |
| index 2e4eb19..45de49f 100644 |
| --- a/lib/vasnprintf.c |
| +++ b/lib/vasnprintf.c |
| @@ -860,7 +860,9 @@ 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; |
| diff --git a/tests/test-vasnprintf.c b/tests/test-vasnprintf.c |
| index 2dd869f..ff68d5c 100644 |
| --- a/tests/test-vasnprintf.c |
| +++ b/tests/test-vasnprintf.c |
| @@ -53,7 +53,24 @@ test_function (char * (*my_asnprintf) (char *, size_t *, const char *, ...)) |
| ASSERT (result != NULL); |
| ASSERT (strcmp (result, "12345") == 0); |
| ASSERT (length == 5); |
| - if (size < 6) |
| + if (size < 5 + 1) |
| + ASSERT (result != buf); |
| + ASSERT (memcmp (buf + size, &"DEADBEEF"[size], 8 - size) == 0); |
| + if (result != buf) |
| + free (result); |
| + } |
| + /* Note: This test assumes IEEE 754 representation of 'double' floats. */ |
| + for (size = 0; size <= 8; size++) |
| + { |
| + size_t length; |
| + char *result; |
| + memcpy (buf, "DEADBEEF", 8); |
| + length = size; |
| + result = my_asnprintf (buf, &length, "%2.0f", 1.6314159265358979e+125); |
| + ASSERT (result != NULL); |
| + ASSERT (strcmp (result, "163141592653589790215729350939528493057529598899734151772468186268423257777068536614838678161083520756952076273094236944990208") == 0); |
| + ASSERT (length == 126); |
| + if (size < 126 + 1) |
| ASSERT (result != buf); |
| ASSERT (memcmp (buf + size, &"DEADBEEF"[size], 8 - size) == 0); |
| if (result != buf) |
| -- |
| 2.7.4 |
| |