Fix a potential double free in EVP_DigestInit_ex

There is a potential double free in EVP_DigestInit_ex. This is believed
to be reached only as a result of programmer error - but we should fix it
anyway.

Issue reported by Guido Vranken.

Reviewed-by: Richard Levitte <levitte@openssl.org>
This commit is contained in:
Matt Caswell 2016-03-14 17:06:19 +00:00
parent 507c7c0ed6
commit ffe9150b15

View File

@ -219,8 +219,10 @@ int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl)
}
#endif
if (ctx->digest != type) {
if (ctx->digest && ctx->digest->ctx_size)
if (ctx->digest && ctx->digest->ctx_size) {
OPENSSL_free(ctx->md_data);
ctx->md_data = NULL;
}
ctx->digest = type;
if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) {
ctx->update = type->update;