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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 2515BC46464 for ; Mon, 13 Aug 2018 19:03:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C855D215A5 for ; Mon, 13 Aug 2018 19:03:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C855D215A5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730660AbeHMVqx (ORCPT ); Mon, 13 Aug 2018 17:46:53 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:32922 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730362AbeHMVqw (ORCPT ); Mon, 13 Aug 2018 17:46:52 -0400 Received: by mail-wr1-f68.google.com with SMTP id g6-v6so15199521wrp.0 for ; Mon, 13 Aug 2018 12:03:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=GtxOWH7di7OYbrM4+U7+5lxwOPYrxG526pYv7074BwA=; b=lFTsBNMJsX4hyU8HgJiIGJYrBh/yZUSeI/em0iwxVwjJRh3h17PBp7LJVtXv6oNsSA BXShdgew4pClvYhaXc/hyKYMYx8j9qMIlUrzUJ0y7Ip1RrofrN2oh3p+hyIo2uMu7IOp B5qKI8mvR40g69sYmvTqr+QfmXweYTdF2d4sD9wT/LITHkuAEF+nmOfZ+oJ4s87ucGHc eS6MVIn8spkZcK59vUb45hPyaEE4XaQwIBY1IxGCxOY/w6cnflGwXnRImxiCc6DQIrCW 59NfqDcSF/DbmKuMFf4aeUKfSTW4ipRbGYeAiQcUZtYKJYQtnC9sZnXGlPCRkkKfqcvU f27A== X-Gm-Message-State: AOUpUlGUNnDut2OAozBi1lhvrwtHfZ0rER1NwpBJkl62PP25utXyaCLo oMRbndCaehj21n6IKG13nhEZIA== X-Google-Smtp-Source: AA+uWPzIqRZQFLpSOMCzDTD/Ff1e3FrIshV+hJ+R7un3tAbpNpLZH0Fjw6vj036uMKSad5RNxYipPA== X-Received: by 2002:adf:f8c7:: with SMTP id f7-v6mr11902248wrq.237.1534187001841; Mon, 13 Aug 2018 12:03:21 -0700 (PDT) Received: from laptop.jcline.org ([2a01:4b00:e003:a100:bac5:4354:4136:4039]) by smtp.gmail.com with ESMTPSA id f132-v6sm12709837wme.24.2018.08.13.12.03.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Aug 2018 12:03:20 -0700 (PDT) Subject: Re: [PATCH 2/2] net: socket: Fix potential spectre v1 gadget in sock_is_registered To: Josh Poimboeuf Cc: "David S . Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20180727224302.5503-1-jcline@redhat.com> <20180727224302.5503-3-jcline@redhat.com> <20180729135906.lgqo5ue6it3hl2da@treble> <914d34af-ba80-93b9-6f17-413eef8bf210@redhat.com> <20180813171642.wlxmnzgsg2rkwe4o@treble> From: Jeremy Cline Openpgp: preference=signencrypt Autocrypt: addr=jcline@redhat.com; keydata= xsFNBFThCPYBEACx9hl05pMfpVKVjm8Yrmd2I3sm9Jw7EIGfn1tmncSnzfveN7UcIjYI23Gw DE11Hf70tMZKXhNmQqDqoftEDwLbTuzBdgJXFZmfEwrcQHGiR5CZ4IQ3U7SF0a701lyYtuNs WndEO8CCaWHUYybiEl1yRZhwyzAA1j/izilD7FckOaEsTM1sFVDs74qWsNGIdJXYQ5dz/iV/ 45wgYNprfMTZQXLvbGIjAD6rmvuArjCQ5GINYSZqO16xZNNWMnS2C0ZFnWz0Fl3VTpukzvO0 ndYT1P4t7pTWT59XPHKKp1Xs25SDO49GTH+hCnaaMjaKL43gVBw1dEu6nY9Nk4EblVnaJv+x 34X1WZFQheglUuPwH04IDZwVE/ACLZPir5eF7zSiRxGOo1COJwg42o5ow4Aq3vbHCONhvGPh kmB5cxcfOyeruurDVcDGu876qFon44l1mPmZWEtYAep3ngQ6zzawfnC2y5Tjm0syX2n6VgBB Y+CR+8jtprwPS4szgbXq5Z+VnxMXAikxrG55vY7uZ2id4z1uqwJRTXdkvzfP52POHuX/Etbz IeQJSQWLqdh4IBXR9QoaXVBwJMMhk5+GYAQ+DXPJzglqxxI/1OuWZi2/2NqrpKMIzXOTxT8/ uUx9jMT9TsFvu5XiiKC5oMvUv2JIW6XQB1Ay73c1niqL5MDdAwARAQABzVRKZXJlbXkgQ2xp bmUgKGh0dHBzOi8vZmVkb3JhcHJvamVjdC5vcmcvd2lraS9Vc2VyOkpjbGluZSkgPGpjbGlu ZUBmZWRvcmFwcm9qZWN0Lm9yZz7CwY4EEwEIADgWIQSvPJnHsb8iwP1BXSvGyJ0h8ZTGQgUC WtDsAQIbAwULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAKCRDGyJ0h8ZTGQuJqD/9zckk1e4Kp 0toGt/pYOVBmdwv/NOJh8w4pFaSq2mdlHkQh0HVnxifWTN0gm9z8ze7cEdj//hElti/wH6lZ E7wFkiwkLBXSZpwQbY/AYQ9a01SJgFE5+7Jk5YI1p3T2V6xgWU5HNUUYcOwxxaJB2ANWep0i KwCvWE0pQFvafVDJaxbAwmL+7/L4Y6YeO5pHCzxv1Vdm54Gy+pKPhEiq/TeqVCx0GrE50stC oAIPa/O8WwYDddNdy75i3DE4kIpgNaGruP5qlHHSKXmLJcRU00njySXxdilKjAWZ66x9hI8+ BfJiyi/WXEb/qmOsh2rVLeRt9tY5xh5vIJTZlqMKLLnC9pJL12KcTd6Me3hKDhKrUighFvFp GRGst7pNPh5j68ZB9sCa9spsIyyspeM3hOBbCQN49DY7LnOMjgXigVqZvBV+3WhFpDkyedmR LaoES6I6iLhtTsuxkxrw8qSqWAbU6Bxm9QeQwikfxhrT415oGABI01da2taI6c96HTp2cGh+ 06TFfcVXuiPPZTf0G2Be+VhE8AU40CGquZBqk1ZDgUAZuZ5H5q9Y6MyRpPwPCW6gV4yUKeXu yyWg0g4ZDCne7uFXNgBSfvmwR9sjb3iYx2Dn4iSWwuQzYk0oNkcIGtMy/NyuBgZwrpiGQIFj fDS4xrtQh9pk0+RbY2HuApeuxM7BTQRU4Qj2ARAApA5cy8aJjeSJQrmnT0g4G/Y3ipaUqY+G s7fEiabuSRjhNilPQbN1KJR7jtSLgu9wzTOAh2MfIShzmLpegWpRCFyZCsLUYWZPe3kPFHZE CdRCA+tCApLE1UswrslCMLwQ2JTV7v6gjv3LUwfw1bSDMNMXJ8MGswbcYUgZpTEASA42yUaW WJgq7olWltlU3MTlR79CmXCRvhQWdsqg4+mdfO6PIuKTy8tx2bzax3jLZ2AV1M7mQi+sJxVn MUZpoUmfj6qMzBWTISGqKFCRMwZAzSEjpY6BvmJ9Vzxbj8M1MCKWlWnZq/ZbhRuoVuXhyFKK mxDU4cclIS+ggHrglibI49M2XSnF9FSCCnlaOd9L+NF7Zx2W1dey7Nq34si7H81opii+ZeO0 au92iIlB8J8t9Ba2dBx0SURWYU/R8g6FyRuDKEO1Y0NpBAwFIjq68tJFyq7reL0HqrxiTI4B 854ZJHpePUnfllWlaEXJ3wJ4UIMSTDNsz/HYuEcch3185sfP1vJ9YRBE7y4N3EEB+dVsfgY/ crsCwMxjukftWfohCLS09rXAkoBQz0luTzHESe3fmMoO5kwbvOJkBOBCEYJz/rqTk24ouc9q PVC6DUX5jmRO+2Ll17O/H1gLpjwVDHi2i2kFSsl88+DThQlJrCGmIwYB6KqvHHNoCotd8Dvb fA8AEQEAAcLBXwQYAQIACQUCVOEI9gIbDAAKCRDGyJ0h8ZTGQi1bD/wMbSCnreanQFYTTgzC 6i/dtsWrd3DvJzaxKdUrSjioP1tK6YLpS7SSc5khYUjVp7xdsu9vCazsLspzBYbQOV02xtI5 CTLwMzh4hYE1/66K899++0v2dP9m9DEKu/R4vqW4axTfWIbR/ygd1bh2a/7NpAT6qiJg8vha Qkf/fVKZ9xM7EDHmfFJscqC6JyYNdYvz8wJ0aa9Z6zvnNUzjAntj62kJV8b8m5diUQDUI8dp r9crk+XxOTNpYid6p8mlNTcX54LTy1eEL7BYG1S3ezcLZC9/78MTdTJbxQMz7/zQXOABfMDy +otLuhEBxi5hl+COIsiRotTOBNPNr1UmV4fQjXz2K6cfgaO/9NilQaEU6zpsMcAOi5lLxlzD GRyPO2a0QQFZ7FmH9dRWw/6mmspQMBNRr5CrQdIBiWDcJGNPl8iX9TqwP62dZgwANT6+FR7K If4axm/gJQMSUCon3eLJhi8b5qZp4vZn7Xj4hCswrO9eExmT9IjpRVcHLYti36m99WRvItDy dVvrvIQi5qah3PrQjtwSJ61ExSZTOpBQGC60yQf+GG0TISIeeXX8CK2e1PIDt7/l+d0onCmU /98IQsNgR/9sifmdPeh3nKsxe2vsa3HNeElQU2ko6ZHMrE0gSyel5vaqRLQQwekBx1mr/7Ll X/87hZ4pdW/aOXUAgQ== Message-ID: Date: Mon, 13 Aug 2018 20:03:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180813171642.wlxmnzgsg2rkwe4o@treble> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/13/2018 06:16 PM, Josh Poimboeuf wrote: > On Sun, Jul 29, 2018 at 11:59:36AM -0400, Jeremy Cline wrote: >> On 07/29/2018 09:59 AM, Josh Poimboeuf wrote: >>> On Fri, Jul 27, 2018 at 10:43:02PM +0000, Jeremy Cline wrote: >>>> 'family' can be a user-controlled value, so sanitize it after the bounds >>>> check to avoid speculative out-of-bounds access. >>>> >>>> Cc: Josh Poimboeuf >>>> Cc: stable@vger.kernel.org >>>> Signed-off-by: Jeremy Cline >>>> --- >>>> net/socket.c | 3 ++- >>>> 1 file changed, 2 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/net/socket.c b/net/socket.c >>>> index f15d5cbb3ba4..608e29ae6baf 100644 >>>> --- a/net/socket.c >>>> +++ b/net/socket.c >>>> @@ -2672,7 +2672,8 @@ EXPORT_SYMBOL(sock_unregister); >>>> >>>> bool sock_is_registered(int family) >>>> { >>>> - return family < NPROTO && rcu_access_pointer(net_families[family]); >>>> + return family < NPROTO && >>>> + rcu_access_pointer(net_families[array_index_nospec(family, NPROTO)]); >>>> } >>>> >>>> static int __init sock_init(void) >>> >>> This is another one where I think it would be better to do the nospec >>> clamp higher up the call chain. The untrusted 'family' value comes from >>> __sock_diag_cmd(): >>> >>> __sock_diag_cmd >>> sock_load_diag_module >>> sock_is_registered >>> >>> That function has a bounds check, and also uses the value in some other >>> array accesses: >>> >>> if (req->sdiag_family >= AF_MAX) >>> return -EINVAL; >>> >>> if (sock_diag_handlers[req->sdiag_family] == NULL) >>> sock_load_diag_module(req->sdiag_family, 0); >>> >>> mutex_lock(&sock_diag_table_mutex); >>> hndl = sock_diag_handlers[req->sdiag_family]; >>> ... >>> >>> So I think clamping 'req->sdiag_family' right after the bounds check >>> would be the way to go. >>> >> >> Indeed, the clamp there would cover this clamp. I had a scheme that I >> quickly fix all the gadgets in functions with local comparisons, but >> clearly that's going to result in call chains with multiple clamps. >> >> I can fix this in a follow-up with a clamp here, or respin this patch >> set, whatever is easier for David. > > Hi Jeremy, > > Just checking up on this... since this patch was merged, will you be > doing a followup patch? > Yes, apologies, I've been traveling. I'll have a patch tomorrow.