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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A510E95A96 for ; Mon, 9 Oct 2023 13:50:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377267AbjJINu6 (ORCPT ); Mon, 9 Oct 2023 09:50:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377417AbjJINuw (ORCPT ); Mon, 9 Oct 2023 09:50:52 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79C83122 for ; Mon, 9 Oct 2023 06:50:49 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1684C433C7; Mon, 9 Oct 2023 13:50:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696859449; bh=bpL+cw7yswjDJTxFDybmlF3/JPt0sLk6XhxRYO6tZDc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MAEGcMfzs+vwQfDwzR2BGLVpZqAmjdN9jfMjFg5a9s7EMLnSb92Rfrgy/q5wjvAnL DbJFfxiuw4+MBGnQiqJU8XIEara8heLJGhOVf6ifl+WZ8k+SYwcDNf7niXQ05jA7oB ep9dh3xgEJrUxRilYKgP0eycTIjaJwE5Z6xavLp0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Ahern , Kyle Zeng , Stephen Suryaputra , Vadim Fedorenko , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 07/91] ipv4: fix null-deref in ipv4_link_failure Date: Mon, 9 Oct 2023 15:05:39 +0200 Message-ID: <20231009130111.789358762@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231009130111.518916887@linuxfoundation.org> References: <20231009130111.518916887@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kyle Zeng [ Upstream commit 0113d9c9d1ccc07f5a3710dac4aa24b6d711278c ] Currently, we assume the skb is associated with a device before calling __ip_options_compile, which is not always the case if it is re-routed by ipvs. When skb->dev is NULL, dev_net(skb->dev) will become null-dereference. This patch adds a check for the edge case and switch to use the net_device from the rtable when skb->dev is NULL. Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") Suggested-by: David Ahern Signed-off-by: Kyle Zeng Cc: Stephen Suryaputra Cc: Vadim Fedorenko Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/route.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 57e2316529d00..9753d07bfc0bf 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1215,6 +1215,7 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) static void ipv4_send_dest_unreach(struct sk_buff *skb) { + struct net_device *dev; struct ip_options opt; int res; @@ -1232,7 +1233,8 @@ static void ipv4_send_dest_unreach(struct sk_buff *skb) opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); rcu_read_lock(); - res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); + dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; + res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); rcu_read_unlock(); if (res) -- 2.40.1