diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 95fcd2d3433e..0fbbc62ed3ed 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -95,7 +95,7 @@ static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp,
 
 	ctx->ctx_doi = XFRM_SC_DOI_LSM;
 	ctx->ctx_alg = XFRM_SC_ALG_SELINUX;
-	ctx->ctx_len = str_len;
+	ctx->ctx_len = str_len + 1;
 	memcpy(ctx->ctx_str, &uctx[1], str_len);
 	ctx->ctx_str[str_len] = '\0';
 	rc = security_context_to_sid(ctx->ctx_str, str_len,