selinux: Fix check for xfrm selinux context algorithm

selinux_xfrm_sec_ctx_alloc accidentally checks the xfrm domain of
interpretation against the selinux context algorithm. This patch
fixes this by checking ctx_alg against the selinux context algorithm.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: NPaul Moore <paul.moore@hp.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

security/selinux/xfrm.c

@@ -208,7 +208,7 @@ static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp,
 	if (!uctx)
 		goto not_from_user;
 
-	if (uctx->ctx_doi != XFRM_SC_ALG_SELINUX)
+	if (uctx->ctx_alg != XFRM_SC_ALG_SELINUX)
 		return -EINVAL;
 
 	str_len = uctx->ctx_len;