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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 2D98DC2D0CD for ; Tue, 17 Dec 2019 20:12:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE22A206D8 for ; Tue, 17 Dec 2019 20:12:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576613537; bh=hCfYOICVQJtSmvDtFvD4zB7rBm7v96AeRD9UugTEBwk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dDKJ8tSFlD+cNgQ2b0/Q81aY+d1djOH/RBPNrdB8SiteMuH6erSKZ+HTyHXIeHWTk O5KP+5hAKioITSnjmy43Fb69I1229vzYB0ztzuty6wDqNkhWeE96gKvX55W3VmlNGm 5f8FrqX1BMwOOURk6JVbn6YhLuNex9wTaUrre36g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728472AbfLQUKp (ORCPT ); Tue, 17 Dec 2019 15:10:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:37014 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728464AbfLQUKp (ORCPT ); Tue, 17 Dec 2019 15:10:45 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3C1A42146E; Tue, 17 Dec 2019 20:10:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576613444; bh=hCfYOICVQJtSmvDtFvD4zB7rBm7v96AeRD9UugTEBwk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F8FoP6htbN91EvgdrxPsnH2ixn84KzCAr0lsQcZw4180UuG1wMqYg4iHdrQqKdELs kN9TwMaG2wLGSDhnifAAGhvt5hlqIrQLKMueysGVh0jTyiFeGQ8p4X0rqyo5Fwnz48 /1428ADn9fw2rmAeTVrTWMu1KLczDJe8h7Pb26sc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lorenzo Bianconi , Cong Wang , William Tu , Simon Horman , "David S. Miller" Subject: [PATCH 5.4 23/37] gre: refetch erspan header from skb->data after pskb_may_pull() Date: Tue, 17 Dec 2019 21:09:44 +0100 Message-Id: <20191217200729.075022800@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191217200721.741054904@linuxfoundation.org> References: <20191217200721.741054904@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Cong Wang [ Upstream commit 0e4940928c26527ce8f97237fef4c8a91cd34207 ] After pskb_may_pull() we should always refetch the header pointers from the skb->data in case it got reallocated. In gre_parse_header(), the erspan header is still fetched from the 'options' pointer which is fetched before pskb_may_pull(). Found this during code review of a KMSAN bug report. Fixes: cb73ee40b1b3 ("net: ip_gre: use erspan key field for tunnel lookup") Cc: Lorenzo Bianconi Signed-off-by: Cong Wang Acked-by: Lorenzo Bianconi Acked-by: William Tu Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/gre_demux.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/gre_demux.c +++ b/net/ipv4/gre_demux.c @@ -127,7 +127,7 @@ int gre_parse_header(struct sk_buff *skb if (!pskb_may_pull(skb, nhs + hdr_len + sizeof(*ershdr))) return -EINVAL; - ershdr = (struct erspan_base_hdr *)options; + ershdr = (struct erspan_base_hdr *)(skb->data + nhs + hdr_len); tpi->key = cpu_to_be32(get_session_id(ershdr)); }