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=-9.8 required=3.0 tests=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 F222DC2D0DB for ; Mon, 20 Jan 2020 16:25:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C62FF2087E for ; Mon, 20 Jan 2020 16:25:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729147AbgATQZz (ORCPT ); Mon, 20 Jan 2020 11:25:55 -0500 Received: from orbyte.nwl.cc ([151.80.46.58]:60802 "EHLO orbyte.nwl.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726897AbgATQZz (ORCPT ); Mon, 20 Jan 2020 11:25:55 -0500 Received: from localhost ([::1]:45660 helo=tatos) by orbyte.nwl.cc with esmtp (Exim 4.91) (envelope-from ) id 1itZs9-000633-RM; Mon, 20 Jan 2020 17:25:53 +0100 From: Phil Sutter To: Pablo Neira Ayuso Cc: netfilter-devel@vger.kernel.org Subject: [nft PATCH 4/4] netlink: Avoid potential NULL-pointer deref in netlink_gen_payload_stmt() Date: Mon, 20 Jan 2020 17:25:40 +0100 Message-Id: <20200120162540.9699-5-phil@nwl.cc> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200120162540.9699-1-phil@nwl.cc> References: <20200120162540.9699-1-phil@nwl.cc> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org With payload_needs_l4csum_update_pseudohdr() unconditionally dereferencing passed 'desc' parameter and a previous check for it to be non-NULL, make sure to call the function only if input is sane. Fixes: 68de70f2b3fc6 ("netlink_linearize: fix IPv6 layer 4 checksum mangling") Signed-off-by: Phil Sutter --- src/netlink_linearize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c index 498326d0087a1..cb1b7fe1748b2 100644 --- a/src/netlink_linearize.c +++ b/src/netlink_linearize.c @@ -941,7 +941,7 @@ static void netlink_gen_payload_stmt(struct netlink_linearize_ctx *ctx, nftnl_expr_set_u32(nle, NFTNL_EXPR_PAYLOAD_CSUM_OFFSET, csum_off / BITS_PER_BYTE); } - if (expr->payload.base == PROTO_BASE_NETWORK_HDR && + if (expr->payload.base == PROTO_BASE_NETWORK_HDR && desc && payload_needs_l4csum_update_pseudohdr(expr, desc)) nftnl_expr_set_u32(nle, NFTNL_EXPR_PAYLOAD_FLAGS, NFT_PAYLOAD_L4CSUM_PSEUDOHDR); -- 2.24.1