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 A109BC77B75 for ; Tue, 18 Apr 2023 12:28:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231425AbjDRM23 (ORCPT ); Tue, 18 Apr 2023 08:28:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231492AbjDRM2W (ORCPT ); Tue, 18 Apr 2023 08:28:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6ECF7A5F5 for ; Tue, 18 Apr 2023 05:28:05 -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 574C4631A6 for ; Tue, 18 Apr 2023 12:27:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 698D1C433D2; Tue, 18 Apr 2023 12:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681820867; bh=g8RbyzLoYXEjUAxoAFTv4YFsoXKsSwTl/Zbn+GAK9os=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pamUXxcsXZfh3RCoQxfy1HTdeP0q92pbDO2DngioJx1J24vmol5orAiVm4CGKTTEP NqUFVRtX4IQvOCBfD28FCnBtF0L4nyArZCgKjnlkyXxvIxk8bMuYTb8fxPx21FNikC 2NK42wgrdEYdzQXKkClt8tN7zZOstnqg4ifMPUiE= 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 4.19 41/57] udp6: fix potential access to stale information Date: Tue, 18 Apr 2023 14:21:41 +0200 Message-Id: <20230418120300.166766356@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120258.713853188@linuxfoundation.org> References: <20230418120258.713853188@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 9b0cae403027e..16c98a2a5c363 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1219,9 +1219,11 @@ 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