test/bntest.c:1821: error: BUFFER_OVERRUN_L3
  Offset added: [8, +oo] Size: [0, +oo] by call to `BN_div`.
Showing all 16 steps of the trace


test/bntest.c:1819:5: Call
1817.               || !TEST_ptr(mont = BN_MONT_CTX_new()))
1818.           goto err;
1819.       BN_zero(zero);
            ^
1820.   
1821.       if (!TEST_false(BN_div(a, b, BN_value_one(), zero, ctx)))

crypto/bn/bn_lib.c:395:1: Parameter `*a->d`
  393.   }
  394.   
  395. > int BN_set_word(BIGNUM *a, BN_ULONG w)
  396.   {
  397.       bn_check_top(a);

crypto/bn/bn_lib.c:398:9: Call
  396.   {
  397.       bn_check_top(a);
  398.       if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL)
                 ^
  399.           return (0);
  400.       a->neg = 0;

crypto/bn/bn_lcl.h:660:1: Parameter `*a->d`
    658.                            const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx);
    659.   
    660. > static ossl_inline BIGNUM *bn_expand(BIGNUM *a, int bits)
    661.   {
    662.       if (bits > (INT_MAX - BN_BITS2 + 1))

test/bntest.c:1821:10: Call
1819.       BN_zero(zero);
1820.   
1821.       if (!TEST_false(BN_div(a, b, BN_value_one(), zero, ctx)))
                 ^
1822.           goto err;
1823.       ERR_clear_error();

crypto/bn/bn_div.c:140:1: Parameter `*dv->d`
  138.    * If 'dv' or 'rm' is NULL, the respective value is not returned.
  139.    */
  140. > int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
  141.              BN_CTX *ctx)
  142.   {

crypto/bn/bn_div.c:257:10: Call
  255.   
  256.       /* Setup to 'res' */
  257.       if (!bn_wexpand(res, (loop + 1)))
                  ^
  258.           goto err;
  259.       res->neg = (num->neg ^ divisor->neg);

crypto/bn/bn_lib.c:948:1: Parameter `*a->d`
    946.   }
    947.   
    948. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
    949.   {
    950.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/bn/bn_lib.c:950:37: Call
    948.   BIGNUM *bn_wexpand(BIGNUM *a, int words)
    949.   {
    950.       return (words <= a->dmax) ? a : bn_expand2(a, words);
                                               ^
    951.   }
    952.   

crypto/bn/bn_lib.c:284:1: Parameter `*b->d`
      282.    */
      283.   
      284. > BIGNUM *bn_expand2(BIGNUM *b, int words)
      285.   {
      286.       bn_check_top(b);

crypto/bn/bn_lib.c:289:23: Call
      287.   
      288.       if (words > b->dmax) {
      289.           BN_ULONG *a = bn_expand_internal(b, words);
                                   ^
      290.           if (!a)
      291.               return NULL;

crypto/bn/bn_lib.c:246:1: <Offset trace>
244.   /* This is used by bn_expand2() */
245.   /* The caller MUST check that words > b->dmax before calling this */
246. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
247.   {
248.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:246:1: Parameter `b->top`
        244.   /* This is used by bn_expand2() */
        245.   /* The caller MUST check that words > b->dmax before calling this */
        246. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
        247.   {
        248.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:246:1: <Length trace>
244.   /* This is used by bn_expand2() */
245.   /* The caller MUST check that words > b->dmax before calling this */
246. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
247.   {
248.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:246:1: Parameter `*b->d`
        244.   /* This is used by bn_expand2() */
        245.   /* The caller MUST check that words > b->dmax before calling this */
        246. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
        247.   {
        248.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:271:9: Array access: Offset added: [8, +oo] Size: [0, +oo] by call to `BN_div` 
        269.       assert(b->top <= words);
        270.       if (b->top > 0)
        271.           memcpy(a, b->d, sizeof(*a) * b->top);
                       ^
        272.   
        273.       return a;

static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
{
    BN_ULONG *a = NULL;
    bn_check_top(b);
    if (words > (INT_MAX / (4 * BN_BITS2))) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG);
        return NULL;
    }
    if (BN_get_flags(b, BN_FLG_STATIC_DATA)) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
        return (NULL);
    }
    if (BN_get_flags(b, BN_FLG_SECURE))
        a = OPENSSL_secure_zalloc(words * sizeof(*a));
    else
        a = OPENSSL_zalloc(words * sizeof(*a));
    if (a == NULL) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE);
        return (NULL);
    }
    assert(b->top <= words);
    if (b->top > 0)
        memcpy(a, b->d, sizeof(*a) * b->top);
    return a;
}
['static int test_badmod()\n{\n    BIGNUM *a = NULL, *b = NULL, *zero = NULL;\n    BN_MONT_CTX *mont = NULL;\n    int st = 0;\n    if (!TEST_ptr(a = BN_new())\n            || !TEST_ptr(b = BN_new())\n            || !TEST_ptr(zero = BN_new())\n            || !TEST_ptr(mont = BN_MONT_CTX_new()))\n        goto err;\n    BN_zero(zero);\n    if (!TEST_false(BN_div(a, b, BN_value_one(), zero, ctx)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_false(BN_mod_mul(a, BN_value_one(), BN_value_one(), zero, ctx)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_false(BN_mod_exp(a, BN_value_one(), BN_value_one(), zero, ctx)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_false(BN_mod_exp_mont(a, BN_value_one(), BN_value_one(),\n                                    zero, ctx, NULL)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_false(BN_mod_exp_mont_consttime(a, BN_value_one(), BN_value_one(),\n                                             zero, ctx, NULL)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_false(BN_MONT_CTX_set(mont, zero, ctx)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_true(BN_set_word(b, 16)))\n        goto err;\n    if (!TEST_false(BN_MONT_CTX_set(mont, b, ctx)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_false(BN_mod_exp_mont(a, BN_value_one(), BN_value_one(),\n                                    b, ctx, NULL)))\n        goto err;\n    ERR_clear_error();\n    if (!TEST_false(BN_mod_exp_mont_consttime(a, BN_value_one(), BN_value_one(),\n                                  b, ctx, NULL)))\n        goto err;\n    ERR_clear_error();\n    st = 1;\nerr:\n    BN_free(a);\n    BN_free(b);\n    BN_free(zero);\n    BN_MONT_CTX_free(mont);\n    return st;\n}', 'int BN_set_word(BIGNUM *a, BN_ULONG w)\n{\n    bn_check_top(a);\n    if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL)\n        return (0);\n    a->neg = 0;\n    a->d[0] = w;\n    a->top = (w ? 1 : 0);\n    bn_check_top(a);\n    return (1);\n}', 'static ossl_inline BIGNUM *bn_expand(BIGNUM *a, int bits)\n{\n    if (bits > (INT_MAX - BN_BITS2 + 1))\n        return NULL;\n    if (((bits+BN_BITS2-1)/BN_BITS2) <= (a)->dmax)\n        return a;\n    return bn_expand2((a),(bits+BN_BITS2-1)/BN_BITS2);\n}', 'int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,\n           BN_CTX *ctx)\n{\n    int norm_shift, i, loop;\n    BIGNUM *tmp, wnum, *snum, *sdiv, *res;\n    BN_ULONG *resp, *wnump;\n    BN_ULONG d0, d1;\n    int num_n, div_n;\n    int no_branch = 0;\n    if ((num->top > 0 && num->d[num->top - 1] == 0) ||\n        (divisor->top > 0 && divisor->d[divisor->top - 1] == 0)) {\n        BNerr(BN_F_BN_DIV, BN_R_NOT_INITIALIZED);\n        return 0;\n    }\n    bn_check_top(num);\n    bn_check_top(divisor);\n    if ((BN_get_flags(num, BN_FLG_CONSTTIME) != 0)\n        || (BN_get_flags(divisor, BN_FLG_CONSTTIME) != 0)) {\n        no_branch = 1;\n    }\n    bn_check_top(dv);\n    bn_check_top(rm);\n    if (BN_is_zero(divisor)) {\n        BNerr(BN_F_BN_DIV, BN_R_DIV_BY_ZERO);\n        return (0);\n    }\n    if (!no_branch && BN_ucmp(num, divisor) < 0) {\n        if (rm != NULL) {\n            if (BN_copy(rm, num) == NULL)\n                return (0);\n        }\n        if (dv != NULL)\n            BN_zero(dv);\n        return (1);\n    }\n    BN_CTX_start(ctx);\n    tmp = BN_CTX_get(ctx);\n    snum = BN_CTX_get(ctx);\n    sdiv = BN_CTX_get(ctx);\n    if (dv == NULL)\n        res = BN_CTX_get(ctx);\n    else\n        res = dv;\n    if (sdiv == NULL || res == NULL || tmp == NULL || snum == NULL)\n        goto err;\n    norm_shift = BN_BITS2 - ((BN_num_bits(divisor)) % BN_BITS2);\n    if (!(BN_lshift(sdiv, divisor, norm_shift)))\n        goto err;\n    sdiv->neg = 0;\n    norm_shift += BN_BITS2;\n    if (!(BN_lshift(snum, num, norm_shift)))\n        goto err;\n    snum->neg = 0;\n    if (no_branch) {\n        if (snum->top <= sdiv->top + 1) {\n            if (bn_wexpand(snum, sdiv->top + 2) == NULL)\n                goto err;\n            for (i = snum->top; i < sdiv->top + 2; i++)\n                snum->d[i] = 0;\n            snum->top = sdiv->top + 2;\n        } else {\n            if (bn_wexpand(snum, snum->top + 1) == NULL)\n                goto err;\n            snum->d[snum->top] = 0;\n            snum->top++;\n        }\n    }\n    div_n = sdiv->top;\n    num_n = snum->top;\n    loop = num_n - div_n;\n    wnum.neg = 0;\n    wnum.d = &(snum->d[loop]);\n    wnum.top = div_n;\n    wnum.dmax = snum->dmax - loop;\n    d0 = sdiv->d[div_n - 1];\n    d1 = (div_n == 1) ? 0 : sdiv->d[div_n - 2];\n    wnump = &(snum->d[num_n - 1]);\n    if (!bn_wexpand(res, (loop + 1)))\n        goto err;\n    res->neg = (num->neg ^ divisor->neg);\n    res->top = loop - no_branch;\n    resp = &(res->d[loop - 1]);\n    if (!bn_wexpand(tmp, (div_n + 1)))\n        goto err;\n    if (!no_branch) {\n        if (BN_ucmp(&wnum, sdiv) >= 0) {\n            bn_clear_top2max(&wnum);\n            bn_sub_words(wnum.d, wnum.d, sdiv->d, div_n);\n            *resp = 1;\n        } else\n            res->top--;\n    }\n    resp++;\n    if (res->top == 0)\n        res->neg = 0;\n    else\n        resp--;\n    for (i = 0; i < loop - 1; i++, wnump--) {\n        BN_ULONG q, l0;\n# if defined(BN_DIV3W) && !defined(OPENSSL_NO_ASM)\n        BN_ULONG bn_div_3_words(BN_ULONG *, BN_ULONG, BN_ULONG);\n        q = bn_div_3_words(wnump, d1, d0);\n# else\n        BN_ULONG n0, n1, rem = 0;\n        n0 = wnump[0];\n        n1 = wnump[-1];\n        if (n0 == d0)\n            q = BN_MASK2;\n        else {\n#  ifdef BN_LLONG\n            BN_ULLONG t2;\n#   if defined(BN_LLONG) && defined(BN_DIV2W) && !defined(bn_div_words)\n            q = (BN_ULONG)(((((BN_ULLONG) n0) << BN_BITS2) | n1) / d0);\n#   else\n            q = bn_div_words(n0, n1, d0);\n#   endif\n#   ifndef REMAINDER_IS_ALREADY_CALCULATED\n            rem = (n1 - q * d0) & BN_MASK2;\n#   endif\n            t2 = (BN_ULLONG) d1 *q;\n            for (;;) {\n                if (t2 <= ((((BN_ULLONG) rem) << BN_BITS2) | wnump[-2]))\n                    break;\n                q--;\n                rem += d0;\n                if (rem < d0)\n                    break;\n                t2 -= d1;\n            }\n#  else\n            BN_ULONG t2l, t2h;\n            q = bn_div_words(n0, n1, d0);\n#   ifndef REMAINDER_IS_ALREADY_CALCULATED\n            rem = (n1 - q * d0) & BN_MASK2;\n#   endif\n#   if defined(BN_UMULT_LOHI)\n            BN_UMULT_LOHI(t2l, t2h, d1, q);\n#   elif defined(BN_UMULT_HIGH)\n            t2l = d1 * q;\n            t2h = BN_UMULT_HIGH(d1, q);\n#   else\n            {\n                BN_ULONG ql, qh;\n                t2l = LBITS(d1);\n                t2h = HBITS(d1);\n                ql = LBITS(q);\n                qh = HBITS(q);\n                mul64(t2l, t2h, ql, qh);\n            }\n#   endif\n            for (;;) {\n                if ((t2h < rem) || ((t2h == rem) && (t2l <= wnump[-2])))\n                    break;\n                q--;\n                rem += d0;\n                if (rem < d0)\n                    break;\n                if (t2l < d1)\n                    t2h--;\n                t2l -= d1;\n            }\n#  endif\n        }\n# endif\n        l0 = bn_mul_words(tmp->d, sdiv->d, div_n, q);\n        tmp->d[div_n] = l0;\n        wnum.d--;\n        if (bn_sub_words(wnum.d, wnum.d, tmp->d, div_n + 1)) {\n            q--;\n            if (bn_add_words(wnum.d, wnum.d, sdiv->d, div_n))\n                (*wnump)++;\n        }\n        resp--;\n        *resp = q;\n    }\n    bn_correct_top(snum);\n    if (rm != NULL) {\n        int neg = num->neg;\n        BN_rshift(rm, snum, norm_shift);\n        if (!BN_is_zero(rm))\n            rm->neg = neg;\n        bn_check_top(rm);\n    }\n    if (no_branch)\n        bn_correct_top(res);\n    BN_CTX_end(ctx);\n    return (1);\n err:\n    bn_check_top(rm);\n    BN_CTX_end(ctx);\n    return (0);\n}', 'BIGNUM *bn_wexpand(BIGNUM *a, int words)\n{\n    return (words <= a->dmax) ? a : bn_expand2(a, words);\n}', 'BIGNUM *bn_expand2(BIGNUM *b, int words)\n{\n    bn_check_top(b);\n    if (words > b->dmax) {\n        BN_ULONG *a = bn_expand_internal(b, words);\n        if (!a)\n            return NULL;\n        if (b->d) {\n            OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0]));\n            bn_free_d(b);\n        }\n        b->d = a;\n        b->dmax = words;\n    }\n    bn_check_top(b);\n    return b;\n}', 'static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)\n{\n    BN_ULONG *a = NULL;\n    bn_check_top(b);\n    if (words > (INT_MAX / (4 * BN_BITS2))) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG);\n        return NULL;\n    }\n    if (BN_get_flags(b, BN_FLG_STATIC_DATA)) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);\n        return (NULL);\n    }\n    if (BN_get_flags(b, BN_FLG_SECURE))\n        a = OPENSSL_secure_zalloc(words * sizeof(*a));\n    else\n        a = OPENSSL_zalloc(words * sizeof(*a));\n    if (a == NULL) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE);\n        return (NULL);\n    }\n    assert(b->top <= words);\n    if (b->top > 0)\n        memcpy(a, b->d, sizeof(*a) * b->top);\n    return a;\n}']