Re: [PATCH 1/8] selftests/sgx: Fix uninitialized pointer dereference in error path

[Huang, Kai]

On Tue, 2023-08-08 at 12:31 -0700, Jo Van Bulck wrote:
> Ensure ctx is zero-initialized, such that the encl_measure function will
> not call EVP_MD_CTX_destroy with an uninitialized ctx pointer in case of an
> early error during key generation.
> 
> Fixes: 2adcba79e69d ("selftests/x86: Add a selftest for SGX")
> Signed-off-by: Jo Van Bulck <jo.vanbulck@xxxxxxxxxxxxxx>
> ---
>  tools/testing/selftests/sgx/sigstruct.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c
> index a07896a46364..d73b29becf5b 100644
> --- a/tools/testing/selftests/sgx/sigstruct.c
> +++ b/tools/testing/selftests/sgx/sigstruct.c
> @@ -318,9 +318,9 @@ bool encl_measure(struct encl *encl)
>  	struct sgx_sigstruct *sigstruct = &encl->sigstruct;
>  	struct sgx_sigstruct_payload payload;
>  	uint8_t digest[SHA256_DIGEST_LENGTH];
> +	EVP_MD_CTX *ctx = NULL;
>  	unsigned int siglen;
>  	RSA *key = NULL;
> -	EVP_MD_CTX *ctx;
>  	int i;
>  
>  	memset(sigstruct, 0, sizeof(*sigstruct));
> @@ -384,7 +384,8 @@ bool encl_measure(struct encl *encl)
>  	return true;
>  
>  err:
> -	EVP_MD_CTX_destroy(ctx);
> +	if (ctx)
> +		EVP_MD_CTX_destroy(ctx);
>  	RSA_free(key);
>  	return false;
>  }

Acked-by: Kai Huang <kai.huang@xxxxxxxxx>