Commit e8e38e14 authored by Chuck Lever's avatar Chuck Lever
Browse files

SUNRPC: Convert svcauth_tls_accept() to use xdr_stream 



Done as part of hardening the server-side RPC header decoding path.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 6181b0c6

net/sunrpc/svcauth_unix.c

+26 −11
Original line number Diff line number Diff line
@@ -807,25 +807,41 @@ struct auth_ops svcauth_null = { 
};





/**

 * svcauth_tls_accept - Decode and validate incoming RPC_AUTH_TLS credential

 * @rqstp: RPC transaction

 *

 * Return values:

 *   %SVC_OK: Both credential and verifier are valid

 *   %SVC_DENIED: Credential or verifier is not valid

 *   %SVC_GARBAGE: Failed to decode credential or verifier

 *   %SVC_CLOSE: Temporary failure

 *

 * rqstp->rq_auth_stat is set as mandated by RFC 5531.

 */

static int

svcauth_tls_accept(struct svc_rqst *rqstp)

{

	struct xdr_stream *xdr = &rqstp->rq_arg_stream;

	struct svc_cred	*cred = &rqstp->rq_cred;

	struct kvec *argv = rqstp->rq_arg.head;

	struct kvec *resv = rqstp->rq_res.head;

	u32 flavor, len;

	void *body;



	if (argv->iov_len < XDR_UNIT * 3)

		return SVC_GARBAGE;

	svcxdr_init_decode(rqstp);



	/* Call's cred length */

	if (svc_getu32(argv) != xdr_zero) {

	/* Length of Call's credential body field: */

	if (xdr_stream_decode_u32(xdr, &len) < 0)

		return SVC_GARBAGE;

	if (len != 0) {

		rqstp->rq_auth_stat = rpc_autherr_badcred;

		return SVC_DENIED;

	}



	/* Call's verifier flavor and its length */

	if (svc_getu32(argv) != rpc_auth_null ||

	    svc_getu32(argv) != xdr_zero) {

	/* Call's verf field: */

	if (xdr_stream_decode_opaque_auth(xdr, &flavor, &body, &len) < 0)

		return SVC_GARBAGE;

	if (flavor != RPC_AUTH_NULL || len != 0) {

		rqstp->rq_auth_stat = rpc_autherr_badverf;

		return SVC_DENIED;

	}
@@ -836,12 +852,12 @@ svcauth_tls_accept(struct svc_rqst *rqstp) 
		return SVC_DENIED;

	}



	/* Mapping to nobody uid/gid is required */

	/* Signal that mapping to nobody uid/gid is required */

	cred->cr_uid = INVALID_UID;

	cred->cr_gid = INVALID_GID;

	cred->cr_group_info = groups_alloc(0);

	if (cred->cr_group_info == NULL)

		return SVC_CLOSE; /* kmalloc failure - client must retry */

		return SVC_CLOSE;



	/* Reply's verifier */

	svc_putnl(resv, RPC_AUTH_NULL);
@@ -853,7 +869,6 @@ svcauth_tls_accept(struct svc_rqst *rqstp) 
		svc_putnl(resv, 0);



	rqstp->rq_cred.cr_flavor = RPC_AUTH_TLS;

	svcxdr_init_decode(rqstp);

	return SVC_OK;

}