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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 ABB1EC2D0DB for ; Wed, 22 Jan 2020 20:33:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ECE72465B for ; Wed, 22 Jan 2020 20:33:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SHddluSy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729050AbgAVUdV (ORCPT ); Wed, 22 Jan 2020 15:33:21 -0500 Received: from mail-pg1-f169.google.com ([209.85.215.169]:34136 "EHLO mail-pg1-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725827AbgAVUdV (ORCPT ); Wed, 22 Jan 2020 15:33:21 -0500 Received: by mail-pg1-f169.google.com with SMTP id r11so142131pgf.1; Wed, 22 Jan 2020 12:33:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=4RP6BcTlBjQVMXjM1GbOC5Sm/jYQcEi+Bbz9d5dA2B0=; b=SHddluSyHGBijvAyXP2Hl4SqgWNTFVJat4Eje1NChQ2CFi4qtOgkNm708l8ZIhS7wz 1mEg6VXWsGVxlJ637VDf1037qp0/lqMa8ArtU132uKr4YWUJiwtpiQdM0VpCkdpdUGtl Cmh4dPreds6MkLI8FFjl+dKuHqQzn1k5mFDrWCOTVS3fHl6dORWZwzHJYsyAXvqrJMNu Y7lqJv2O5YmZWKuakuybUPb5GIyr7G5yb+e0JZjd1uBAbEiOAcW9cKpir1BID3ZX7MdX lq7g4pet5hiSzLNQcxIdbLLGJzihfpW2UgDf+Tva6kLOJVNBEMOFBs2BbD2QT9bny/RZ eDRw== 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:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=4RP6BcTlBjQVMXjM1GbOC5Sm/jYQcEi+Bbz9d5dA2B0=; b=EC1AEQQI6BbR1pZpMEmSh13ifJPl+k1l5aPcVOj7s0g62uR84l+wyjen6IGD/MXaPz dAIe2JlPHua/jd8+jdVU0HUTGlN9fxeTThEkgAMHkLhTwZ2jexQrPqb8WyGz5oMgPuus gqX6RMChEADfRkK1KJ8pwE75hahcf0tm3S32a5Lb1YhC4yEyhVLsQMiqrBVrB4HREXUo MJH+1hxgeF5WG4R1c5R3u3yhj8H0bOUipt3VU1fUfIk+EAYSx6wAtf7PyaieaPcwyEUr 5yDam+EY75HRR91+A6ySgE3MobydQ2WGZ6KLWHA8uU0s74i3lI4ScD/mg4BEYcgsVaXP hZRQ== X-Gm-Message-State: APjAAAWDBIESDW8H5KjnWrLO8QPRpSlnlPcKeAk7zPU/mhme3S19jaf3 BneTsf02QjaeGHEPd0wpvQM= X-Google-Smtp-Source: APXvYqzlV5lkAnjIz1BAKafCf0OTzYSWs59fCfLYXg7BESa+BX/CtvsckclFy7mTfQTBDw4KMt3vFQ== X-Received: by 2002:aa7:800e:: with SMTP id j14mr4400945pfi.174.1579725200636; Wed, 22 Jan 2020 12:33:20 -0800 (PST) Received: from ?IPv6:2620:15c:2c1:200:55c7:81e6:c7d8:94b? ([2620:15c:2c1:200:55c7:81e6:c7d8:94b]) by smtp.gmail.com with ESMTPSA id fa21sm4353738pjb.17.2020.01.22.12.33.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 22 Jan 2020 12:33:19 -0800 (PST) Subject: Re: KASAN: slab-out-of-bounds Read in __nla_put_nohdr To: Cong Wang , Eric Dumazet Cc: syzbot , David Miller , Jamal Hadi Salim , Jiri Pirko , LKML , Linux Kernel Network Developers , syzkaller-bugs References: <0000000000006370ef059cabac14@google.com> <50239085-ff0f-f797-99af-1a0e58bc5e2e@gmail.com> From: Eric Dumazet Message-ID: <7056f971-8fae-ce88-7e9a-7983e4f57bb2@gmail.com> Date: Wed, 22 Jan 2020 12:33:17 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 1/22/20 12:27 PM, Cong Wang wrote: > On Tue, Jan 21, 2020 at 11:55 AM Eric Dumazet wrote: >> em_nbyte_change() sets >> em->datalen = sizeof(*nbyte) + nbyte->len; >> >> But later tcf_em_validate() overwrites em->datalen with the user provide value (em->datalen = data_len; ) >> which can be bigger than the allocated (kmemdup) space in em_nbyte_change() >> >> Should net/sched/em_nbyte.c() provide a dump() handler to avoid this issue ? > > I think for those who implement ->change() we should leave > ->datalen untouched to respect their choices. I don't see why > we have to set it twice. > > Agreed, but we need to audit them to make sure all of them are setting ->datalen