From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.1 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,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 220ACC433E0 for ; Sun, 9 Aug 2020 02:36:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF4212065C for ; Sun, 9 Aug 2020 02:36:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="t7tPPT0u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726377AbgHICgU (ORCPT ); Sat, 8 Aug 2020 22:36:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726291AbgHICgU (ORCPT ); Sat, 8 Aug 2020 22:36:20 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27E6AC061756; Sat, 8 Aug 2020 19:36:20 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id j21so3044344pgi.9; Sat, 08 Aug 2020 19:36:20 -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:mime-version :content-transfer-encoding; bh=kub7wUC7iBpeOQedwXMHPG2fSSd6JGXHHrf1fpHFbPE=; b=t7tPPT0uU7FlYa5L++Ikfzy6rXwiljuECk4lu27SHPAazvDNgSpuEhfFcZmx93l1AH 4FXV9lW+dfDAsIT2irs4JEaXxK5+3SEpW94sI3r5vATWanaXb+QxPhujqw21y2fOjc8A rcF4sU0WgHaJeTdFZr3QnBI0Ib/YIiwWPQmwVUpHpBGOnupStR9XSZUz8KuKSWb7QBj1 ySmX1yVqxYQpcpdm4w676QrfjnI4WURyuCRNcPjyRzuYZoUsIFrg8BJvnG/Wp4hFUbX3 d+87ReIhWqwn2GaEwpDHlszH3AcIy1PcTIa9PJsrm9XNE0bi2rQSI4/JxSfGF9fGEMnn 4Krw== 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:mime-version :content-transfer-encoding; bh=kub7wUC7iBpeOQedwXMHPG2fSSd6JGXHHrf1fpHFbPE=; b=WWr0VdZhq3e/18bmLCewcS/RHHhdaoXmkM2Tps5jnZS3/tidJyI/OSE3CbnlUtSMnI 54VU2ZSO3pilOB6RIEHrLw+7mCEt0OUODANOa8eEOGCSD8IauHHerMJCryEQimg0cCfU xBvqrh79NylDHOaKjWtBUlzqU1VH5UcoiMIkZ4xdYyBFbfj9QFfossFsSKwWrVyJbrGD 9cRhBXteEAlR36f8GV85aH635yb7wKbbTDMCmDud1SxXkWM4FWLt6qIrj6XZ4B3kRG2b KfF3zbf9/Gv1PkYeuycGfUVRvo0cw5U4xsKsqJyKyXSVh9lZH0tEfIPoSy6GluPJ3rKC EpzQ== X-Gm-Message-State: AOAM533w5MtdYxQBXofqdXxwMlf1RIkazgOp3VMn52/tEKrEVQlvXKrL RONv1ZOdFP/kwQFd5QtVw98= X-Google-Smtp-Source: ABdhPJzBKl/FpkmB9RNIJz9i97dyxxK2mcalwmGHXp0o63E43rV9CYCkzDT49Htdm+uZqq+Iz0Jg7Q== X-Received: by 2002:a63:cd56:: with SMTP id a22mr16634662pgj.259.1596940579278; Sat, 08 Aug 2020 19:36:19 -0700 (PDT) Received: from shane-XPS-13-9380.hsd1.ca.comcast.net ([2601:646:8880:9ae0:8cf2:183:7fb5:ce6a]) by smtp.gmail.com with ESMTPSA id gn13sm15280089pjb.17.2020.08.08.19.36.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 08 Aug 2020 19:36:18 -0700 (PDT) From: Xie He To: "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-x25@vger.kernel.org Cc: Xie He , Willem de Bruijn , Martin Schiller Subject: [PATCH net] drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check Date: Sat, 8 Aug 2020 19:35:48 -0700 Message-Id: <20200809023548.684217-1-xie.he.0141@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 1. Added a skb->len check This driver expects upper layers to include a pseudo header of 1 byte when passing down a skb for transmission. This driver will read this 1-byte header. This patch added a skb->len check before reading the header to make sure the header exists. 2. Added needed_headroom When this driver transmits data, first this driver will remove a pseudo header of 1 byte, then the lapb module will prepend the LAPB header of 2 or 3 bytes. So the value of needed_headroom in this driver should be 3 - 1. Cc: Willem de Bruijn Cc: Martin Schiller Signed-off-by: Xie He --- drivers/net/wan/x25_asy.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c index 84640a0c13f3..de7984463595 100644 --- a/drivers/net/wan/x25_asy.c +++ b/drivers/net/wan/x25_asy.c @@ -307,6 +307,14 @@ static netdev_tx_t x25_asy_xmit(struct sk_buff *skb, return NETDEV_TX_OK; } + /* There should be a pseudo header of 1 byte added by upper layers. + * Check to make sure it is there before reading it. + */ + if (skb->len < 1) { + kfree_skb(skb); + return NETDEV_TX_OK; + } + switch (skb->data[0]) { case X25_IFACE_DATA: break; @@ -752,6 +760,12 @@ static void x25_asy_setup(struct net_device *dev) dev->type = ARPHRD_X25; dev->tx_queue_len = 10; + /* When transmitting data: + * first this driver removes a pseudo header of 1 byte, + * then the lapb module prepends an LAPB header of at most 3 bytes. + */ + dev->needed_headroom = 3 - 1; + /* New-style flags. */ dev->flags = IFF_NOARP; } -- 2.25.1