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=-5.3 required=3.0 tests=BAYES_00, 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 3BC4BC64995 for ; Tue, 20 Jul 2021 16:12:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 280826100C for ; Tue, 20 Jul 2021 16:12:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229638AbhGTPba (ORCPT ); Tue, 20 Jul 2021 11:31:30 -0400 Received: from mail-pj1-f45.google.com ([209.85.216.45]:42698 "EHLO mail-pj1-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239738AbhGTPVO (ORCPT ); Tue, 20 Jul 2021 11:21:14 -0400 Received: by mail-pj1-f45.google.com with SMTP id i16-20020a17090acf90b02901736d9d2218so2708072pju.1 for ; Tue, 20 Jul 2021 09:01:50 -0700 (PDT) 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=46C4IWqrWyR5qyJte4yy/LNABCP3MNuxTfw+EkoTt0A=; b=PMk7vWyrcfc4ijwQ6pz/KwM7oyXLAbI8n6MESzZICaVMBcN0A1WAsu8XmQ7DoVA5Ln Ps4o/deRrCKa7ZxYPifhng9XRScz/hMST3ixGt+NoPbNxLBSYiZhjv/ez0qWCGFQh5PW hxd7HpkBTg2+6JSM3XVAI59Lkr2xemVmFEtO213EFw09RzYR3ycRMzVVTk4H9SRPZjDD oldpIBUgomX6cazUhYMWxyveSlABPTl3yKKgqN/9ODcgAf6ldfwHAblMzQPHwWvfFn78 jRgjDIsPO1FkDmxuFIgKapf2hBoZcDfNUmdsIcrjB8MPtAspzMvvdO1O/EsnmC2oQpV2 cxCQ== X-Gm-Message-State: AOAM532QqQG2zAtkQsLIbvaWeHF9uDIGAl1/gS5omsYkF+EmVC4+HZyk vEtYW5VvoWkapbxaSs8+dL4= X-Google-Smtp-Source: ABdhPJxEEJTPH4kGqcSL/bhsdjVj38DlFEKWBO7jQvTBfmDL/AMiPzTCpCwiaAbS0POlzrssoJ9xuQ== X-Received: by 2002:a17:90b:190:: with SMTP id t16mr7092520pjs.221.1626796909879; Tue, 20 Jul 2021 09:01:49 -0700 (PDT) Received: from ?IPv6:2601:647:4000:d7:9fa9:39d2:8b59:76ce? ([2601:647:4000:d7:9fa9:39d2:8b59:76ce]) by smtp.gmail.com with ESMTPSA id ie13sm3208891pjb.45.2021.07.20.09.01.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 20 Jul 2021 09:01:49 -0700 (PDT) Subject: Re: [PATCH] scsi: ufs: Fix memory corruption by ufshcd_read_desc_param() To: Avri Altman , "Martin K . Petersen" Cc: Jaegeuk Kim , "linux-scsi@vger.kernel.org" , "James E.J. Bottomley" , Can Guo , Stanley Chu , Bean Huo , Asutosh Das References: <20210719231127.869088-1-bvanassche@acm.org> From: Bart Van Assche Message-ID: Date: Tue, 20 Jul 2021 09:01:47 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 7/19/21 11:45 PM, Avri Altman wrote: >> If param_offset > buff_len then the memcpy() statement in >> ufshcd_read_desc_param() corrupts memory since it copies >> 256 + buff_len - param_offset bytes into a buffer with size buff_len. >> Since param_offset < 256 this results in writing past the bound of the output >> buffer. > > param_offset >= buff_len is tested in line 3381? Hi Avri, That's correct. However, a few lines lower there is the following code: ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC, desc_id, desc_index, 0, desc_buf, &buff_len); That call may modify (reduce) 'buff_len'. Hence, a second check is needed. Thanks, Bart.