Files
heimdal/lib/hcrypto/libtommath/bn_mp_grow.c
czurnieden fd2d434dd3 libtommath: Fix possible integer overflow CVE-2023-36328
Cherry picked from libtommath 7bbc1f8e4fe6dce75055957645117180768efb15.

Vulnerability Detail:
  CVE Identifier: CVE-2023-36328
  Description: Integer Overflow vulnerability in mp_grow in libtom
    libtommath before commit beba892bc0d4e4ded4d667ab1d2a94f4d75109a9,
    allows attackers to execute arbitrary code and cause a denial of
    service (DoS).
  Reference: https://nvd.nist.gov/vuln/detail/CVE-2023-36328

Reported-by: https://github.com/Crispy-fried-chicken
2024-09-10 09:00:32 -04:00

43 lines
1.1 KiB
C

#include "tommath_private.h"
#ifdef BN_MP_GROW_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* grow as required */
mp_err mp_grow(mp_int *a, int size)
{
int i;
mp_digit *tmp;
if (size < 0) {
return MP_VAL;
}
/* if the alloc size is smaller alloc more ram */
if (a->alloc < size) {
/* reallocate the array a->dp
*
* We store the return in a temporary variable
* in case the operation failed we don't want
* to overwrite the dp member of a.
*/
tmp = (mp_digit *) MP_REALLOC(a->dp,
(size_t)a->alloc * sizeof(mp_digit),
(size_t)size * sizeof(mp_digit));
if (tmp == NULL) {
/* reallocation failed but "a" is still valid [can be freed] */
return MP_MEM;
}
/* reallocation succeeded so set a->dp */
a->dp = tmp;
/* zero excess digits */
i = a->alloc;
a->alloc = size;
MP_ZERO_DIGITS(a->dp + i, a->alloc - i);
}
return MP_OKAY;
}
#endif