From patchwork Wed Oct 28 13:18:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xie He X-Patchwork-Id: 316133 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30F08C4363A for ; Wed, 28 Oct 2020 22:40:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D00C120878 for ; Wed, 28 Oct 2020 22:40:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NqrrPl5I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389095AbgJ1Wku (ORCPT ); Wed, 28 Oct 2020 18:40:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389070AbgJ1Wks (ORCPT ); Wed, 28 Oct 2020 18:40:48 -0400 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B38E7C0613CF; Wed, 28 Oct 2020 15:40:47 -0700 (PDT) Received: by mail-pl1-x644.google.com with SMTP id b19so360360pld.0; Wed, 28 Oct 2020 15:40:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ZgaymEmZcwxxsKVYh/F35SxRK5AS1vNWLJ9SX/my/Ac=; b=NqrrPl5IAyqECj76dMGuM5xm0RZ8Rj4wyDANCyUbxak5WfXMSUyNgEQpwgTwH0hNXA vRE5OQhTwoy+hPQUX38GvmZ/Cb31P5hS4C34PM/Xf2RgHhMQsDrKCu+08N1H76Cqxssk f1yPZFJRoS0UFf6h3tXs0cdd5IVYo/x/v84OCS/PfelbxTwxr7/EfBnO5PWt7/DXM5az O2dExDvPxJoeJilvFLa3NdqejDOGmHwweQBXGysoGMGhoGPQR2nUrIJQavjBx7BHb2H2 qvXrlEO5jvqSIqReEc4kxy8uWjtMW+nrgYUIGpxpbzjQxCZ/C1IaF5vnKSWJUvmdCAIr SaQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ZgaymEmZcwxxsKVYh/F35SxRK5AS1vNWLJ9SX/my/Ac=; b=aQS90mTuGr9dcuWCthu/4iWt2MqneLco0mTrQRNfw2uN8nbPJbD8amdYxIAYyE+zPL LL+N06gmjfPpBjba50fXFU7hDdMqUjGPOmEmSQ0J56Gucp8R+fzeKlZ+EflEj3pykOHG /D0tKzvLuus4k6lLPALX9lx/jkUnqfWHVIePsiMNYWbgBzBoGP2RaSoBvF29kv/ojALY /0MyiyOIzgtE2pUmmzCXKAu2zQuCS5CFQ4eHcCzZw5V5fqBEANU91OUu8rfT1BC9Z57H p1rwmL4QHra1OTbUmWZ77hgyPbLVzUiFCioSft+9tOmeD6RMSuFvSlMHqgKkxnxxWTjR ls9A== X-Gm-Message-State: AOAM5322k3yn9yQMEB0kmyG10yycC3JPj0gE7jQvgXk2sb7QwGfOSG1e qmDDk5ReZEl5t2GqBXXeBvNJKPEvrTQ= X-Google-Smtp-Source: ABdhPJwwqxKGvnkuElikx8r2ZmXj4J4dw/eIAsTBCBcc5R6EwV9aBOXJh9cadR+PMdDSrN0BBfwVXw== X-Received: by 2002:a17:902:b492:b029:d4:d88c:d1a7 with SMTP id y18-20020a170902b492b02900d4d88cd1a7mr7508840plr.15.1603891193194; Wed, 28 Oct 2020 06:19:53 -0700 (PDT) Received: from shane-XPS-13-9380.hsd1.ca.comcast.net ([2601:646:8800:1c00:6d80:dec8:7340:3009]) by smtp.gmail.com with ESMTPSA id r8sm7058032pgn.30.2020.10.28.06.19.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Oct 2020 06:19:52 -0700 (PDT) From: Xie He To: Jakub Kicinski , "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Krzysztof Halasa Cc: Xie He Subject: [PATCH net-next v2 3/4] net: hdlc_fr: Improve the initial check when we receive an skb Date: Wed, 28 Oct 2020 06:18:06 -0700 Message-Id: <20201028131807.3371-4-xie.he.0141@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201028131807.3371-1-xie.he.0141@gmail.com> References: <20201028131807.3371-1-xie.he.0141@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 1. Change the skb->len check from "<= 4" to "< 4". At first we only need to ensure a 4-byte header is present. We indeed normally need the 5th byte, too, but it'd be more logical and cleaner to check its existence when we actually need it. 2. Add an fh->ea2 check to the initial checks in fr_fx. fh->ea2 == 1 means the second address byte is the final address byte. We only support the case where the address length is 2 bytes. Cc: Krzysztof Halasa Signed-off-by: Xie He --- drivers/net/wan/hdlc_fr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index ac65f5c435ef..3639c2bfb141 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -882,7 +882,7 @@ static int fr_rx(struct sk_buff *skb) struct pvc_device *pvc; struct net_device *dev; - if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI) + if (skb->len < 4 || fh->ea1 || !fh->ea2 || data[2] != FR_UI) goto rx_error; dlci = q922_to_dlci(skb->data);