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[209.132.180.67]) by mx.google.com with ESMTP id u191si14367990oia.86.2019.12.28.04.52.44; Sat, 28 Dec 2019 04:53:17 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@web.de header.s=dbaedf251592 header.b=U5S7Vu+w; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726371AbfL1Mua (ORCPT + 99 others); Sat, 28 Dec 2019 07:50:30 -0500 Received: from mout.web.de ([217.72.192.78]:55465 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726187AbfL1Mua (ORCPT ); Sat, 28 Dec 2019 07:50:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1577537424; bh=P/t4loOx1AZXrhxHmvrhi+3XMNCVOGRlEHmFQSjRAb4=; h=X-UI-Sender-Class:To:Cc:References:Subject:From:Date:In-Reply-To; b=U5S7Vu+wWiZDLURSaw0p68G2/8Jq9Rr9OQleF1lardcC9dCo1q5/RKRLZQHU100Uj n7tiaV39bbA6tHRxl8hVfcJycbpoOMgkk+kJtbjjkRIsoWv0pJDrr7mzDDZEyQ1EIg 9CUTJWP2nnq7DXHLCN464wVGzdddBFIRNlQJc6RE= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.1.2] ([78.48.3.151]) by smtp.web.de (mrweb103 [213.165.67.124]) with ESMTPSA (Nemesis) id 0LqDYi-1jOw8u1lBo-00do5g; Sat, 28 Dec 2019 13:50:24 +0100 To: Xu Wang , linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Wolfram Sang References: <1577439272-10362-1-git-send-email-vulab@iscas.ac.cn> Subject: Re: [PATCH 2/2] i2c: Fix a potential use after free From: Markus Elfring Autocrypt: addr=Markus.Elfring@web.de; prefer-encrypt=mutual; keydata= mQINBFg2+xABEADBJW2hoUoFXVFWTeKbqqif8VjszdMkriilx90WB5c0ddWQX14h6w5bT/A8 +v43YoGpDNyhgA0w9CEhuwfZrE91GocMtjLO67TAc2i2nxMc/FJRDI0OemO4VJ9RwID6ltwt mpVJgXGKkNJ1ey+QOXouzlErVvE2fRh+KXXN1Q7fSmTJlAW9XJYHS3BDHb0uRpymRSX3O+E2 lA87C7R8qAigPDZi6Z7UmwIA83ZMKXQ5stA0lhPyYgQcM7fh7V4ZYhnR0I5/qkUoxKpqaYLp YHBczVP+Zx/zHOM0KQphOMbU7X3c1pmMruoe6ti9uZzqZSLsF+NKXFEPBS665tQr66HJvZvY GMDlntZFAZ6xQvCC1r3MGoxEC1tuEa24vPCC9RZ9wk2sY5Csbva0WwYv3WKRZZBv8eIhGMxs rcpeGShRFyZ/0BYO53wZAPV1pEhGLLxd8eLN/nEWjJE0ejakPC1H/mt5F+yQBJAzz9JzbToU 5jKLu0SugNI18MspJut8AiA1M44CIWrNHXvWsQ+nnBKHDHHYZu7MoXlOmB32ndsfPthR3GSv jN7YD4Ad724H8fhRijmC1+RpuSce7w2JLj5cYj4MlccmNb8YUxsE8brY2WkXQYS8Ivse39MX BE66MQN0r5DQ6oqgoJ4gHIVBUv/ZwgcmUNS5gQkNCFA0dWXznQARAQABtCZNYXJrdXMgRWxm cmluZyA8TWFya3VzLkVsZnJpbmdAd2ViLmRlPokCVAQTAQgAPhYhBHDP0hzibeXjwQ/ITuU9 Figxg9azBQJYNvsQAhsjBQkJZgGABQsJCAcCBhUICQoLAgQWAgMBAh4BAheAAAoJEOU9Figx g9azcyMP/iVihZkZ4VyH3/wlV3nRiXvSreqg+pGPI3c8J6DjP9zvz7QHN35zWM++1yNek7Ar OVXwuKBo18ASlYzZPTFJZwQQdkZSV+atwIzG3US50ZZ4p7VyUuDuQQVVqFlaf6qZOkwHSnk+ CeGxlDz1POSHY17VbJG2CzPuqMfgBtqIU1dODFLpFq4oIAwEOG6fxRa59qbsTLXxyw+PzRaR LIjVOit28raM83Efk07JKow8URb4u1n7k9RGAcnsM5/WMLRbDYjWTx0lJ2WO9zYwPgRykhn2 sOyJVXk9xVESGTwEPbTtfHM+4x0n0gC6GzfTMvwvZ9G6xoM0S4/+lgbaaa9t5tT/PrsvJiob kfqDrPbmSwr2G5mHnSM9M7B+w8odjmQFOwAjfcxoVIHxC4Cl/GAAKsX3KNKTspCHR0Yag78w i8duH/eEd4tB8twcqCi3aCgWoIrhjNS0myusmuA89kAWFFW5z26qNCOefovCx8drdMXQfMYv g5lRk821ZCNBosfRUvcMXoY6lTwHLIDrEfkJQtjxfdTlWQdwr0mM5ye7vd83AManSQwutgpI q+wE8CNY2VN9xAlE7OhcmWXlnAw3MJLW863SXdGlnkA3N+U4BoKQSIToGuXARQ14IMNvfeKX NphLPpUUnUNdfxAHu/S3tPTc/E/oePbHo794dnEm57LuuQINBFg2+xABEADZg/T+4o5qj4cw nd0G5pFy7ACxk28mSrLuva9tyzqPgRZ2bdPiwNXJUvBg1es2u81urekeUvGvnERB/TKekp25 4wU3I2lEhIXj5NVdLc6eU5czZQs4YEZbu1U5iqhhZmKhlLrhLlZv2whLOXRlLwi4jAzXIZAu 76mT813jbczl2dwxFxcT8XRzk9+dwzNTdOg75683uinMgskiiul+dzd6sumdOhRZR7YBT+xC wzfykOgBKnzfFscMwKR0iuHNB+VdEnZw80XGZi4N1ku81DHxmo2HG3icg7CwO1ih2jx8ik0r riIyMhJrTXgR1hF6kQnX7p2mXe6K0s8tQFK0ZZmYpZuGYYsV05OvU8yqrRVL/GYvy4Xgplm3 DuMuC7/A9/BfmxZVEPAS1gW6QQ8vSO4zf60zREKoSNYeiv+tURM2KOEj8tCMZN3k3sNASfoG fMvTvOjT0yzMbJsI1jwLwy5uA2JVdSLoWzBD8awZ2X/eCU9YDZeGuWmxzIHvkuMj8FfX8cK/ 2m437UA877eqmcgiEy/3B7XeHUipOL83gjfq4ETzVmxVswkVvZvR6j2blQVr+MhCZPq83Ota xNB7QptPxJuNRZ49gtT6uQkyGI+2daXqkj/Mot5tKxNKtM1Vbr/3b+AEMA7qLz7QjhgGJcie qp4b0gELjY1Oe9dBAXMiDwARAQABiQI8BBgBCAAmFiEEcM/SHOJt5ePBD8hO5T0WKDGD1rMF Alg2+xACGwwFCQlmAYAACgkQ5T0WKDGD1rOYSw/+P6fYSZjTJDAl9XNfXRjRRyJSfaw6N1pA Ahuu0MIa3djFRuFCrAHUaaFZf5V2iW5xhGnrhDwE1Ksf7tlstSne/G0a+Ef7vhUyeTn6U/0m +/BrsCsBUXhqeNuraGUtaleatQijXfuemUwgB+mE3B0SobE601XLo6MYIhPh8MG32MKO5kOY hB5jzyor7WoN3ETVNQoGgMzPVWIRElwpcXr+yGoTLAOpG7nkAUBBj9n9TPpSdt/npfok9ZfL /Q+ranrxb2Cy4tvOPxeVfR58XveX85ICrW9VHPVq9sJf/a24bMm6+qEg1V/G7u/AM3fM8U2m tdrTqOrfxklZ7beppGKzC1/WLrcr072vrdiN0icyOHQlfWmaPv0pUnW3AwtiMYngT96BevfA qlwaymjPTvH+cTXScnbydfOQW8220JQwykUe+sHRZfAF5TS2YCkQvsyf7vIpSqo/ttDk4+xc Z/wsLiWTgKlih2QYULvW61XU+mWsK8+ZlYUrRMpkauN4CJ5yTpvp+Orcz5KixHQmc5tbkLWf x0n1QFc1xxJhbzN+r9djSGGN/5IBDfUqSANC8cWzHpWaHmSuU3JSAMB/N+yQjIad2ztTckZY pwT6oxng29LzZspTYUEzMz3wK2jQHw+U66qBFk8whA7B2uAU1QdGyPgahLYSOa4XAEGb6wbI FEE= Message-ID: <81b35c80-74c2-e14e-4947-f23ec6197b73@web.de> Date: Sat, 28 Dec 2019 13:50:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <1577439272-10362-1-git-send-email-vulab@iscas.ac.cn> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Provags-ID: V03:K1:PrlI48dhLIRO4YeSVp6+HSERej6UZEC1VTswfIipTcz1KRENdhI UprKZGwX39QOiDTyw/+iAvJ7TdcadlrNykilJhX0Tp40e+WTe+2yilm/ED/DSgcQq1BRBio oeHVdbt6rw5E9tl9n09eMwsdDT8rGWDKfZfcYzEZWlCpTWhQeFXoqXymcNRSDkU/TZo3mAw lZYJ5yIhlQzeQswMxw8OA== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:hrv+lr/SgQ8=:ClWDXTGwdl8Ujwl4Jr7FZA l5yO5Q5K0olZ+L3A7TyqQ7/ZpTDZH4AAtjve3fKUpEmFGMKKEiZoMvXvwxw0LbRkSQ+HokVrx huECg7bPzrROZ3IGC3KU1kLt+VweIsyQggLuk4oK9Q1QmUxx8QcwrTBpaZ1APe3avDBL/b++9 gAWmrYZ61HT/o7uqgL1rxRRBiHhV59uz3MISDdAYMdCE5hLalqO2FdChyg38MnehUuM7VgQPy 4nZqnZRl2ddiO+2Htp/ZPsEqmYfHLgRbwBEjoeOKjpBX3TG/evXYZv9DT3pBgn8By4AUfOEed WyV2MCr7MRsflm2iIyEW1U75jSGFsJOBgGOOsIg3fRW6RXnOqX+zViXBIV7HciTQAGBXszOF4 3JRseR4uG6d4mVGQ1ck2wuDszsTUF+lHOcEVdkDjmshurjd5PnSr2L8aXMMdPG8vI50fRfrq/ VBSpQQ77itmbdCNjNc+T4hbmb3/PJWFF1UjAQtascDnxmQ+mVoJ7EGRtNGzaavXQsGYKdVJLF 3NWbkA1xuGDmPvcTDnj9JbO9UaK7ZhKfuDRTmrszHRERzyHC2GeeUlWhHQqdPhAbjOoPVQay6 MDRnJ/lH7DF2wWattuV8z1E3RrKPMdPvT1GOZgHMLw/b0W7aGC+PG768ot/3k5vJSkvokjJry LVXjTpjcij+CF13aEVGjxI2izLGdK6pGN8hFe8rhUii4A7oNlT67swDsHF9IGLh5V5rGcwprP prYHa4mk5QzLoVVbdQTU2B+SU1pNwHhtjIJYU7l2kM6o7NoLiYycC0Zo5OROR9ELEP4TaIj7N IbYy8W93hR0qWoRxe3p0eKhU9Bh08PWg7oP1XCCgLTXb/hTtclwP9G6azSKuw/8bdosI8+Ap7 EccfvQS/rbLKRbtvUXx+us4RXz8wqi/7iZH3ChdWk1cLNUiu4dRIlU3ojv8h1NNIwKAfkiODT bukJWbi/4JJLsGQ51V2rRphhTZnyE4nWWVgZdl/FOQ5crofV4GcMGzctOo2DYKpPsQc2e7ips CXYeFbfULgKHO2d1ctSRT4XuBtmHTQZD7GuxuQ0+4TUZalvui/+H9P0H8fpDsCVRVrV2hAzLF qIb7jXOZCCArA37yr8XU4fbyRCRLo5+PXDkhw1eid6xI63vBsBtyjnLHruxmbpxV+Lyp2ZG7e iCsaTmXil24tBr7e9gYlns3oRbiNQnJ4Llhc8rOCPneK2C4moMwUUljUQZlBpHn03wkC7Omrm yN50Ikpr3k46ecRQsrDk/5dPSTXamnNK2FTreowOyS0/pND11p3+YqvC5a9Y= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Free the adap structure only after we are done using it. This information can be reasonable. > This patch just moves the put_device() down a bit to avoid the > use after free. I suggest to reconsider such a change because a device reference count should eventually be decremented before decrementing the reference count for the module which is managed by this programming interface. Would you like to clarify the dependencies for such an use case any more? Regards, Markus