Re: [Libtirpc-devel] [PATCH v3] Avoid buffer overruns by allocating buffer in svcauth_gss_validate()

[Steve Dickson <SteveD@redhat.com>]

On 05/28/2014 03:09 PM, Steve Dickson wrote:
> Signed-off-by: Steve Dickson <steved@redhat.com>
Committed... 

steved.

> ---
>  src/svc_auth_gss.c |   14 +++++++-------
>  1 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/src/svc_auth_gss.c b/src/svc_auth_gss.c
> index 601a691..26c1065 100644
> --- a/src/svc_auth_gss.c
> +++ b/src/svc_auth_gss.c
> @@ -286,21 +286,19 @@ svcauth_gss_validate(struct svc_rpc_gss_data *gd, struct rpc_msg *msg)
>  	struct opaque_auth	*oa;
>  	gss_buffer_desc		 rpcbuf, checksum;
>  	OM_uint32		 maj_stat, min_stat, qop_state;
> -	u_char			 rpchdr[128];
> +	u_char			 *rpchdr;
>  	int32_t			*buf;
>  
>  	gss_log_debug("in svcauth_gss_validate()");
>  
> -	memset(rpchdr, 0, sizeof(rpchdr));
> -
>  	/* XXX - Reconstruct RPC header for signing (from xdr_callmsg). */
>  	oa = &msg->rm_call.cb_cred;
>  	if (oa->oa_length > MAX_AUTH_BYTES)
>  		return (FALSE);
> -	
> -	/* 8 XDR units from the IXDR macro calls. */
> -	if (sizeof(rpchdr) < (8 * BYTES_PER_XDR_UNIT +
> -			RNDUP(oa->oa_length)))
> +
> +	rpchdr = (u_char *)calloc(((8 * BYTES_PER_XDR_UNIT) + 
> +			RNDUP(oa->oa_length)), 1);
> +	if (rpchdr == NULL)
>  		return (FALSE);
>  
>  	buf = (int32_t *)rpchdr;
> @@ -325,6 +323,8 @@ svcauth_gss_validate(struct svc_rpc_gss_data *gd, struct rpc_msg *msg)
>  	maj_stat = gss_verify_mic(&min_stat, gd->ctx, &rpcbuf, &checksum,
>  				  &qop_state);
>  
> +	free(rpchdr);
> +
>  	if (maj_stat != GSS_S_COMPLETE) {
>  		gss_log_status("gss_verify_mic", maj_stat, min_stat);
>  		return (FALSE);
>