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 22581C7619A for ; Wed, 12 Apr 2023 13:03:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229799AbjDLNDQ (ORCPT ); Wed, 12 Apr 2023 09:03:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229753AbjDLNDP (ORCPT ); Wed, 12 Apr 2023 09:03:15 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E51A4EDD for ; Wed, 12 Apr 2023 06:03:10 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 85-20020a250b58000000b00b8f071f5062so8019595ybl.20 for ; Wed, 12 Apr 2023 06:03:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1681304589; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:from:to:cc:subject:date:message-id:reply-to; bh=taes8BYJjZPc9U0iN1DeNr6Fcbi/Nev444CdlhzzD5A=; b=bbBs0KKHVSQpukby4h7ktqUAZSymmnCFv9wXpBmz0pY/8FveI1HOvXzmjiGtwto37N WyyPNOLOzmCoeAD25VX3h56D/UwcH8Fjr/2KZOHGStY7o8mVARpo6Mg9brmeG5nybTAf 4T6ToLWotyjmRxf0sjIWyQJ9FB41H/RXbmtK1uZqdfSUo7NiVm8yXN+YRVin2rp2xH+x GShh0ImNG6vQuvGWwwyC1jbK/5iPaBjSebMzOW44XsuO7ihw3fDpADyG8N/iU9HUvWga H5ZtYP3p7ScyIKjMvDd4pzAcZiThG2THt8O28HBFqBuWcD0wOuJrOb0tgv427CDEWAS8 FRJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681304589; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=taes8BYJjZPc9U0iN1DeNr6Fcbi/Nev444CdlhzzD5A=; b=HWReFEHlRIium+b8QG0CmsHjeXT8lcweie7RxQamq068cysv7sUlWHKSgGgaCK1+8i qa/5OYEuj75lnLKjxMY29flnSZ2nqmXofPV1yisb7rqFCTv4lDiKL2eCsHb7lYqkVhnC sC3kP0msMrQgWL1DutRc7hm/XSYf5GWzhn4ZaxEzbAR6I5tGEIVSqdkA6bXrgH2iW1oj zzvvAAomndZqwDn0FOSTEHRZ+I2jNjeYzxiGmDS80z2nI/eL8B2Qz+1eofbvMPTESl4I LaxmiONYK6Hz7KEQI88tUhrkTNpSsXoBs0NzXwvXJRnVeUM30tSNSEt/QRXyF35vv48x NcbQ== X-Gm-Message-State: AAQBX9djVMx7WDTJlXgCTcUJ6zvowLI5I5GzwrT7NJyVpF7cGK8Lo2Uw ZQuhyANfJuq24/1IT5KLNFcJi4avjhBiVg== X-Google-Smtp-Source: AKy350aSmDGYsdck73mVZLNRh+K/a9PSx9jVqKOhJq9+lwdKCQ1CBnEM6jL2IFHzfB/kdgBcYTZIJ4Qp9KGTmA== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a25:d705:0:b0:b6b:6a39:949c with SMTP id o5-20020a25d705000000b00b6b6a39949cmr6963293ybg.6.1681304589355; Wed, 12 Apr 2023 06:03:09 -0700 (PDT) Date: Wed, 12 Apr 2023 13:03:08 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.0.577.gac1e443424-goog Message-ID: <20230412130308.1202254-1-edumazet@google.com> Subject: [PATCH net] udp6: fix potential access to stale information From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet , lena wang , "=?UTF-8?q?Maciej=20=C5=BBenczykowski?=" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 >=3D 0) { used_address->name_len =3D 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 Cc: Maciej =C5=BBenczykowski --- 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 9fb2f33ee3a76a09bbe15a9aaf1371a804f91ee2..a675acfb901d102ce56563b1d50= ae827d9e04859 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1395,9 +1395,11 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *ms= g, size_t len) msg->msg_name =3D &sin; msg->msg_namelen =3D sizeof(sin); do_udp_sendmsg: - if (ipv6_only_sock(sk)) - return -ENETUNREACH; - return udp_sendmsg(sk, msg, len); + err =3D ipv6_only_sock(sk) ? + -ENETUNREACH : udp_sendmsg(sk, msg, len); + msg->msg_name =3D sin6; + msg->msg_namelen =3D addr_len; + return err; } } =20 --=20 2.40.0.577.gac1e443424-goog