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 45C8EC77B7D for ; Tue, 18 Apr 2023 12:38:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231802AbjDRMiz (ORCPT ); Tue, 18 Apr 2023 08:38:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231797AbjDRMiy (ORCPT ); Tue, 18 Apr 2023 08:38:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D9184699 for ; Tue, 18 Apr 2023 05:38:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E39B8632C2 for ; Tue, 18 Apr 2023 12:38:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03C3DC433EF; Tue, 18 Apr 2023 12:38:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681821528; bh=WNWEFS5CsuWrgh/uto+zkswrGyXbcLgIZLOzPBaJG/E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YwV1aeQC/YBPmPURDjGKy8jQc9Ala62XY2Ux8TyE61ycDG17eWVnb1peem6im8+cg n0cHPYhLjscbHZwPkKIEV21JwWKIalO0OCPZ2WiyUuoIELQnicmDtYIpiZ/mHQU9yk QqH6uCLp2DCMQwBGnQ91O6Vv0sWgsGXr9jLr00Q8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, lena wang , Eric Dumazet , =?UTF-8?q?Maciej=20=C5=BBenczykowski?= , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 34/91] udp6: fix potential access to stale information Date: Tue, 18 Apr 2023 14:21:38 +0200 Message-Id: <20230418120306.771437689@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120305.520719816@linuxfoundation.org> References: <20230418120305.520719816@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit 1c5950fc6fe996235f1d18539b9c6b64b597f50f ] lena wang reported an issue caused by udpv6_sendmsg() mangling msg->msg_name and msg->msg_namelen, which are later read from ____sys_sendmsg() : /* * If this is sendmmsg() and sending to current destination address was * successful, remember it. */ if (used_address && err >= 0) { used_address->name_len = msg_sys->msg_namelen; if (msg_sys->msg_name) memcpy(&used_address->name, msg_sys->msg_name, used_address->name_len); } udpv6_sendmsg() wants to pretend the remote address family is AF_INET in order to call udp_sendmsg(). A fix would be to modify the address in-place, instead of using a local variable, but this could have other side effects. Instead, restore initial values before we return from udpv6_sendmsg(). Fixes: c71d8ebe7a44 ("net: Fix security_socket_sendmsg() bypass problem.") Reported-by: lena wang Signed-off-by: Eric Dumazet Reviewed-by: Maciej Żenczykowski Link: https://lore.kernel.org/r/20230412130308.1202254-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/udp.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 9dfb4bb54344b..921129c3df8ad 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1359,9 +1359,11 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) msg->msg_name = &sin; msg->msg_namelen = sizeof(sin); do_udp_sendmsg: - if (__ipv6_only_sock(sk)) - return -ENETUNREACH; - return udp_sendmsg(sk, msg, len); + err = __ipv6_only_sock(sk) ? + -ENETUNREACH : udp_sendmsg(sk, msg, len); + msg->msg_name = sin6; + msg->msg_namelen = addr_len; + return err; } } -- 2.39.2