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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 1091FC4363D for ; Thu, 24 Sep 2020 19:25:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4D92D20878 for ; Thu, 24 Sep 2020 19:25:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="VWe62aC/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D92D20878 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 83D596B005C; Thu, 24 Sep 2020 15:25:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 814926B005D; Thu, 24 Sep 2020 15:25:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 72BC36B0062; Thu, 24 Sep 2020 15:25:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0177.hostedemail.com [216.40.44.177]) by kanga.kvack.org (Postfix) with ESMTP id 5E3376B005C for ; Thu, 24 Sep 2020 15:25:16 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 1EF611F0A for ; Thu, 24 Sep 2020 19:25:16 +0000 (UTC) X-FDA: 77298933432.09.hate92_3b03a6227161 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id 03BA7180AD801 for ; Thu, 24 Sep 2020 19:25:15 +0000 (UTC) X-HE-Tag: hate92_3b03a6227161 X-Filterd-Recvd-Size: 3043 Received: from hqnvemgate26.nvidia.com (hqnvemgate26.nvidia.com [216.228.121.65]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Thu, 24 Sep 2020 19:25:15 +0000 (UTC) Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Thu, 24 Sep 2020 12:25:01 -0700 Received: from rcampbell-dev.nvidia.com (172.20.13.39) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 24 Sep 2020 19:25:12 +0000 Subject: Re: [PATCH v2] mm/hmm/test: use after free in dmirror_allocate_chunk() To: Dan Carpenter , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= CC: Wei Yongjun , Jason Gunthorpe , , , References: <20200924134651.GA1586456@mwanda> X-Nvconfidentiality: public From: Ralph Campbell Message-ID: Date: Thu, 24 Sep 2020 12:25:11 -0700 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: <20200924134651.GA1586456@mwanda> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [172.20.13.39] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1600975501; bh=VxKXOti6LWxDsQHTJ8Vj6sJYvHX2OPdhnAxzokJEpJg=; h=Subject:To:CC:References:X-Nvconfidentiality:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:Content-Type:Content-Language: Content-Transfer-Encoding:X-Originating-IP:X-ClientProxiedBy; b=VWe62aC/uYbjVEz9Y/oRUv63BSpflwyw97N4YqYQZny3VxkgKrxHPAA2sEsXIvz/h 9KL49FsSXjFOWcHW9XBFrqjqS5o3RMX3GEAv2i4YrAXVGyIATZqZt2MENtoJNpfoeg Pb9j1mTx6yZY+Mwa55uGK0YreUWiRnOqUs3dMNOyP2s9t63Ug8O2kC1i8/nDvsx9UD WgExzgVBLmlflvobXN7Y5DCdjjcXeQz7fgGopgKcmclxp+FDCVnFRV0jhJ/BUwx7yW 9bjoQH9JPJROAhA42UdEOnmDFbynM5+V47+SVZ71utQpLDVVm7uIbp8QzvN9iRZZEm BSthl/AxF/aUw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 9/24/20 6:46 AM, Dan Carpenter wrote: > The error handling code does this: > > err_free: > kfree(devmem); > ^^^^^^^^^^^^^ > err_release: > release_mem_region(devmem->pagemap.range.start, range_len(&devmem->pagemap.range)); > ^^^^^^^^ > The problem is that when we use "devmem->pagemap.range.start" the > "devmem" pointer is either NULL or freed. > > Neither the allocation nor the call to request_free_mem_region() has to > be done under the lock so I moved those to the start of the function. > > Fixes: b2ef9f5a5cb3 ("mm/hmm/test: add selftest driver for HMM") > Signed-off-by: Dan Carpenter Looks good. Reviewed-by: Ralph Campbell