Commit 6f137370 authored by Matt Caswell's avatar Matt Caswell
Browse files

Client side CKE processing can double free on error 



The tls_client_key_exchange_post_work() frees the pms on error. It also
calls ssl_generate_master_secret() which also free the pms. If an error
occurs after ssl_generate_master_secret() has been called then a double
free can occur.

Reviewed-by: default avatarAndy Polyakov <appro@openssl.org>
parent b8f1c116

ssl/statem/statem_clnt.c

+8 −2
Original line number Diff line number Diff line
@@ -2547,6 +2547,9 @@ int tls_client_key_exchange_post_work(SSL *s) 
    unsigned char *pms = NULL;

    size_t pmslen = 0;



    pms = s->s3->tmp.pms;

    pmslen = s->s3->tmp.pmslen;



#ifndef OPENSSL_NO_SRP

    /* Check for SRP */

    if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
@@ -2558,8 +2561,6 @@ int tls_client_key_exchange_post_work(SSL *s) 
        return 1;

    }

#endif

    pms = s->s3->tmp.pms;

    pmslen = s->s3->tmp.pmslen;



    if (pms == NULL && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {

        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
@@ -2569,8 +2570,13 @@ int tls_client_key_exchange_post_work(SSL *s) 
    if (!ssl_generate_master_secret(s, pms, pmslen, 1)) {

        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);

        SSLerr(SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK, ERR_R_INTERNAL_ERROR);

        /* ssl_generate_master_secret frees the pms even on error */

        pms = NULL;

        pmslen = 0;

        goto err;

    }

    pms = NULL;

    pmslen = 0;



#ifndef OPENSSL_NO_SCTP

    if (SSL_IS_DTLS(s)) {