Commit acc60092 authored by Kurt Roeckx's avatar Kurt Roeckx
Browse files

Avoid creating an illegal pointer 



Found by tis-interpreter

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>

GH: #1106
parent 169a8e39

crypto/bn/bn_div.c

+5 −1
Original line number Diff line number Diff line
@@ -278,6 +278,9 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor, 
            res->top--;

    }



    /* Increase the resp pointer so that we never create an invalid pointer. */

    resp++;



    /*

     * if res->top == 0 then clear the neg value otherwise decrease the resp

     * pointer
@@ -287,7 +290,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor, 
    else

        resp--;



    for (i = 0; i < loop - 1; i++, wnump--, resp--) {

    for (i = 0; i < loop - 1; i++, wnump--) {

        BN_ULONG q, l0;

        /*

         * the first part of the loop uses the top two words of snum and sdiv
@@ -393,6 +396,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor, 
                (*wnump)++;

        }

        /* store part of the result */

        resp--;

        *resp = q;

    }

    bn_correct_top(snum);