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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 01715C636CD for ; Sun, 5 Feb 2023 10:42:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pOcTc-0003br-W6; Sun, 05 Feb 2023 05:42:29 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pOcTb-0003be-MH for qemu-devel@nongnu.org; Sun, 05 Feb 2023 05:42:27 -0500 Received: from mail-ej1-x635.google.com ([2a00:1450:4864:20::635]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pOcTZ-0002bp-T4 for qemu-devel@nongnu.org; Sun, 05 Feb 2023 05:42:27 -0500 Received: by mail-ej1-x635.google.com with SMTP id gr7so26717177ejb.5 for ; Sun, 05 Feb 2023 02:42:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=4Rx+cKhz51XWo2cs5Wh4CzNxzUzWqAGIbRQx8z2eT+8=; b=EpQjI/hsREj4RSO4L0HQYpqj9pxOWBjshpf/dYoE8+oqubgconHOKhyIY5aUNDkbnG BJEC8SbBtSUl8Qk1cCX61aQdZ7eNzCJbHoxyj+rD9Kzuyi7Jz2AyxbyuwBuSwSWwwNwt ibL7z4LTLsp4EiAZu3yK6tWCTQGSzJtiUSYJE3+ClDIl9Vvq6D7CZ1up0269NtIbWTtN gQVp7777RmyDqLtYvrKxEEUew1iZdLBPOYZb6hLPu/0XWBwL9WCC0DBNXEOwabcF8yZg HGI9dP1kpC0J26dPKGW8QgEXMgWUlZZmsCYA71tLOlONvD5Sk6G/QSTDM0WIk6Vs5FQ/ lP8w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=4Rx+cKhz51XWo2cs5Wh4CzNxzUzWqAGIbRQx8z2eT+8=; b=Q0b336xwyu2FCtA2WGbte7sbQi6hBm4lc7MKwJ69ds94xQr2OK9Iix8yZvFz4aC8ZV g8FO0PygrZ17XaR9cRNx9MTI8yDJBcfcLKGddT5P2jmE41G1nsqlv+NAlORsaWJABy0U JWImVEvgxFxFyWn6nZsoqOoAjJMzXsq+Rk51pq2rEluvy0R4aXYs6FM0tONskbkrZ+mj 9slSoh35NEcJ6wGq4Y10oDp4i86j57SC2ZhWhdt6POBx0EPBLD8xaBJVcaKEIxuoa3R2 nbdk5ur1+Rs84aHlX3dYpAB0nRBuSaMji/SkStm8z47r6mqOxpiW1jW8bbiwKXiUG6Cn v3YA== X-Gm-Message-State: AO0yUKX8RqUsDvkNZsyVNzJEtkNQQNJ+/Qp6tvJPpk0/vrZBCUykg448 Y92hVzPwwUTGsDJh2DMMXAwyYA== X-Google-Smtp-Source: AK7set/+LSTPaUPDU7QlWqUCZ4fqRxern4+YJMz//uO3k5Gp8oOqzJ1/apUD+Z8uLdQMkz/PRM5ulw== X-Received: by 2002:a17:907:9d08:b0:879:36b4:486 with SMTP id kt8-20020a1709079d0800b0087936b40486mr19452593ejc.13.1675593744495; Sun, 05 Feb 2023 02:42:24 -0800 (PST) Received: from [192.168.1.115] ([185.126.107.38]) by smtp.gmail.com with ESMTPSA id rn26-20020a170906d93a00b008845c668408sm3931925ejb.169.2023.02.05.02.42.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 05 Feb 2023 02:42:23 -0800 (PST) Message-ID: Date: Sun, 5 Feb 2023 11:42:22 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH 04/10] fuzz/generic-fuzz: add a limit on DMA bytes written Content-Language: en-US To: Alexander Bulekov , qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Bandan Das , Darren Kenny , Paolo Bonzini , Thomas Huth , Qiuhao Li , Laurent Vivier References: <20230205042951.3570008-1-alxndr@bu.edu> <20230205042951.3570008-5-alxndr@bu.edu> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= In-Reply-To: <20230205042951.3570008-5-alxndr@bu.edu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::635; envelope-from=philmd@linaro.org; helo=mail-ej1-x635.google.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.09, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 5/2/23 05:29, Alexander Bulekov wrote: > As we have repplaced fork-based fuzzing, with reboots - we can no longer Typo "replaced". > use a timeout+exit() to avoid slow inputs. Libfuzzer has its own timer > that it uses to catch slow inputs, however these timeouts are usually > seconds-minutes long: more than enough to bog-down the fuzzing process. > However, I found that slow inputs often attempt to fill overly large DMA > requests. Thus, we can mitigate most timeouts by setting a cap on the > total number of DMA bytes written by an input. > > Signed-off-by: Alexander Bulekov > --- > tests/qtest/fuzz/generic_fuzz.c | 5 +++++ > 1 file changed, 5 insertions(+) Reviewed-by: Philippe Mathieu-Daudé