From patchwork Tue Mar 17 23:27:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Eckelmann X-Patchwork-Id: 229172 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=-9.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU, 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 25493C5ACD6 for ; Tue, 17 Mar 2020 23:28:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE00C20738 for ; Tue, 17 Mar 2020 23:28:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b="n4bJ7Djv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727113AbgCQX2A (ORCPT ); Tue, 17 Mar 2020 19:28:00 -0400 Received: from dvalin.narfation.org ([213.160.73.56]:53462 "EHLO dvalin.narfation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727071AbgCQX2A (ORCPT ); Tue, 17 Mar 2020 19:28:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1584487678; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cI2KT7XmC8wBvCNsS0QrRiOP99i3tKuDrJ5+PvlAvLQ=; b=n4bJ7DjvTCtzAow8hffuAUJKJk4FQ9F+ObHxkksV7WS6om0JmQzrkeqJInhkLoaji9LGu6 CYQGSoOMYd+AFiOJetpqSZ6m+J5/ovTZvHlSRsIjs3sj8ukX2UyyMpr55M3eoiBzn7D9fB zBbkJ9yMjzgBuO3WMZbTiYUfYS7h124= From: Sven Eckelmann To: stable@vger.kernel.org Cc: Sven Eckelmann , Marek Lindner , Simon Wunderlich Subject: [PATCH 4.4 17/48] batman-adv: Avoid nullptr dereference in dat after vlan_insert_tag Date: Wed, 18 Mar 2020 00:27:03 +0100 Message-Id: <20200317232734.6127-18-sven@narfation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200317232734.6127-1-sven@narfation.org> References: <20200317232734.6127-1-sven@narfation.org> MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit 60154a1e0495ffb8343a95cefe1e874634572fa8 upstream. vlan_insert_tag can return NULL on errors. The distributed arp table code therefore has to check the return value of vlan_insert_tag for NULL before it can safely operate on this pointer. Fixes: be1db4f6615b ("batman-adv: make the Distributed ARP Table vlan aware") Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Signed-off-by: Simon Wunderlich --- net/batman-adv/distributed-arp-table.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 76808c5e8183..f890b13fad43 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -993,9 +993,12 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, if (!skb_new) goto out; - if (vid & BATADV_VLAN_HAS_TAG) + if (vid & BATADV_VLAN_HAS_TAG) { skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), vid & VLAN_VID_MASK); + if (!skb_new) + goto out; + } skb_reset_mac_header(skb_new); skb_new->protocol = eth_type_trans(skb_new, @@ -1073,9 +1076,12 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, */ skb_reset_mac_header(skb_new); - if (vid & BATADV_VLAN_HAS_TAG) + if (vid & BATADV_VLAN_HAS_TAG) { skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q), vid & VLAN_VID_MASK); + if (!skb_new) + goto out; + } /* To preserve backwards compatibility, the node has choose the outgoing * format based on the incoming request packet type. The assumption is