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=-6.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 52B58C4338F for ; Sun, 15 Aug 2021 08:49:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27A9E61042 for ; Sun, 15 Aug 2021 08:49:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236717AbhHOIuD (ORCPT ); Sun, 15 Aug 2021 04:50:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236425AbhHOIuC (ORCPT ); Sun, 15 Aug 2021 04:50:02 -0400 Received: from mail-lf1-x133.google.com (mail-lf1-x133.google.com [IPv6:2a00:1450:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 400D2C061764; Sun, 15 Aug 2021 01:49:32 -0700 (PDT) Received: by mail-lf1-x133.google.com with SMTP id x27so28371798lfu.5; Sun, 15 Aug 2021 01:49:32 -0700 (PDT) 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=N9F061E103kzIB2bNqHdTfx672Vo2UjZty49a/4DJ+w=; b=OhHaAV9O+FHFRjcYeAaP+svuQawi9NmDbJrnB42D893+TC3jfIhEhsGp3LypOIj25N 6qFOa+ganVg9wUolLUURshmKPMhuxozf/7QgdxXd8LbO/9ti8HxodkC9XJBDisOcObm5 B7z82DZ6Ol4/m9O/Ipj/1WB9rvJbtwyn5yXIZ6dLbaGt7yYIa8B0ybkgmYFmi3jWX3j4 7ybKvPsbftc7JABSrCwlv9G3J4qEW5hv0Tw5+rhar8uL4Zii9gTR8l5C/udxnzr2+g/4 +DPa08VkTSL7yQRDay5++uPxTfmBlSm5od23vT1uEFv8RkAZDB796fNa9T+Y9YiU5zLL rJWw== 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=N9F061E103kzIB2bNqHdTfx672Vo2UjZty49a/4DJ+w=; b=Nd5/P1Kk6RbLMxwFciWjCPS97s5emKuhbk6xQnncG6N12erSmE3yGX2jgmw2c3Hu16 9reiKg0kVSESA2XAiXEuC23iLiCJX+/yGlDdX/U892GPr7R1Bh9iXepPoms971KrHSMg xnthgfcE42GehsU0Y7IOTwJJKnzRFDpOWWrhu6dn8Y6R6eQnfu+/RLqeaTur3PjjmY+E 5z0TMyHHe0aHrO2ClAScAVgrrVZmV/SJqHJNmMk7UpG2nXv3+j9CDOD7pdGq5sEAhPYt BILxKJlMFm9dPSwnv4j46OyLkIYXZD8z4gfg49dozSd3gNx/QMMcuQYJZA2hV0x9dFba 1oDw== X-Gm-Message-State: AOAM532t/RjyqxUwsxO4MhoRZZzHPbdO2L6y5iCb2C/qDMXZW4jGUI7R YQKzbj0B0dnal6ly368a67Q= X-Google-Smtp-Source: ABdhPJzQPUhgvswLIbgJZSq9C56IDi0X9Jz/n4DB4TI3eYFRJyA6ROtj4DrLmzqTg7TidjWcb6VMGQ== X-Received: by 2002:ac2:5a0b:: with SMTP id q11mr7623433lfn.578.1629017370317; Sun, 15 Aug 2021 01:49:30 -0700 (PDT) Received: from localhost.localdomain ([185.215.60.79]) by smtp.gmail.com with ESMTPSA id x26sm618967lfu.206.2021.08.15.01.49.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 15 Aug 2021 01:49:29 -0700 (PDT) Subject: Re: [PATCH] media: mxl111sf: change mutex_init() location To: Sean Young Cc: mkrufky@linuxtv.org, mchehab@kernel.org, crope@iki.fi, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+5ca0bf339f13c4243001@syzkaller.appspotmail.com References: <20210730213829.2909-1-paskripkin@gmail.com> <20210815083755.GA1827@gofer.mess.org> From: Pavel Skripkin Message-ID: <7ee99788-d9a5-0a38-ed02-51d9b42ebc11@gmail.com> Date: Sun, 15 Aug 2021 11:49:26 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <20210815083755.GA1827@gofer.mess.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 8/15/21 11:37 AM, Sean Young wrote: > On Sat, Jul 31, 2021 at 12:38:29AM +0300, Pavel Skripkin wrote: >> Syzbot reported, that mxl111sf_ctrl_msg() uses uninitialized >> mutex. The problem was in wrong mutex_init() location. >> >> Previous mutex_init(&state->msg_lock) call was in ->init() function, but >> dvb_usbv2_init() has this order of calls: >> >> dvb_usbv2_init() >> dvb_usbv2_adapter_init() >> dvb_usbv2_adapter_frontend_init() >> props->frontend_attach() >> >> props->init() >> >> Since mxl111sf_frontend_attach_atsc_mh() calls mxl111sf_ctrl_msg() >> internally we need to initialize state->msg_lock in it to make lockdep >> happy. > > What about the other frontends like mxl111sf_frontend_attach_dvbt? They > no longer initialize the mutex. > Good point. I see, that all other frontends also call mxl111sf_ctrl_msg() inside ->frontend_attach() call. I think, that fixing dvb-usb core is not good idea, so, I will add mutex_init() call inside all frontends, which use mxl111sf_init(). What do you think about it? With regards, Pavel Skripkin