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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1778AC433DF for ; Tue, 28 Jul 2020 09:00:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF24120775 for ; Tue, 28 Jul 2020 09:00:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728396AbgG1JAg (ORCPT ); Tue, 28 Jul 2020 05:00:36 -0400 Received: from mout.kundenserver.de ([217.72.192.73]:56557 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726032AbgG1JAg (ORCPT ); Tue, 28 Jul 2020 05:00:36 -0400 Received: from mail-qv1-f42.google.com ([209.85.219.42]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.145]) with ESMTPSA (Nemesis) id 1N7Qp1-1krjrg3oQ1-017nYF; Tue, 28 Jul 2020 11:00:34 +0200 Received: by mail-qv1-f42.google.com with SMTP id y11so5817012qvl.4; Tue, 28 Jul 2020 02:00:33 -0700 (PDT) X-Gm-Message-State: AOAM530VPtxzYmmfQKA5oHkCar+PhTxxZNXrtHW4btTVztmDhQCPB+AJ 8Pl1IiHWOgO/Jwpp7HbClrTUgsSSKdOqNnbApYo= X-Google-Smtp-Source: ABdhPJyHJknGj8GUNL8xLpz4Ao+RH8HsvsNIXL/Mx8WnbEJnfPHwMfS9/LuIY4gTuNauTXnxx9R4Pbevp0lgD1BJOnI= X-Received: by 2002:a0c:a992:: with SMTP id a18mr25130279qvb.211.1595926832698; Tue, 28 Jul 2020 02:00:32 -0700 (PDT) MIME-Version: 1.0 References: <20200726220557.102300-1-yepeilin.cs@gmail.com> <20200726222703.102701-1-yepeilin.cs@gmail.com> <20200727131608.GD1913@kadam> <20200727220456.GA328887@PWN> In-Reply-To: <20200727220456.GA328887@PWN> From: Arnd Bergmann Date: Tue, 28 Jul 2020 11:00:16 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [Linux-kernel-mentees] [PATCH v3] media/v4l2-core: Fix kernel-infoleak in video_put_user() To: Peilin Ye Cc: Dan Carpenter , Mauro Carvalho Chehab , Greg Kroah-Hartman , syzkaller-bugs , Hans Verkuil , Sakari Ailus , Laurent Pinchart , Vandana BN , Ezequiel Garcia , =?UTF-8?Q?Niklas_S=C3=B6derlund?= , linux-kernel-mentees@lists.linuxfoundation.org, Linux Media Mailing List , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:CsD6pvTl7tWkdFLkCMHcNsU0Eb4AjJHFhM1opzQVkq9DqNF9F2K 3+hAq11J4C3r1H5dbAf6BIpro/m/Ere+KE6QfRYzrfKDJG5LfMjPVB389+aBmwdejXyYR4e oa85ajNCA5fclBFViosNxoLkGI4deAQMIUmxPNjAdP+cdkj/bmQ13N+ev4s7TQsOqHDpRY/ eMe/pNgUcAPttZgLCYATQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:o1YSR9rzFCI=:jgDnK1hBT7TXge87+gIjLY SH1LcwCSrFgyWIZAxDkSR+RvNR3HfX7bZbLWCD9y/An6LOOMFFejr6d10LyZNWVLtvad/25lK 8WQ23F59vklG19FGaI5ZK/SrnLZSVgwRWjEtsXjNMC9YvEp3x7ufXhDP3KgYUZKxXm3FROwvw +B5hAsYJ9l+LQH8DlllJ7cIFBuSyCPeURYModC8Spwq/6EOcKigdTGsfuK3hesWUHv2L2HC6N IKLpS+XMfCCSRd5EEBEhxj+erzZRnJXjOjSy6YCKolTDeJsWO+exlP51HmBxzPa+tym0gbL2F 1rE6LGwH33cOgbR1bkCslsF3Z9diMX1b+4L/9RWTPJQ/H+1wtZScqq+oS2/CFl5UnqQxcn4ns pePjB6Gc/2jXtPoU35bDxLe1d3ihchJERnF8l8G4jjCSaJD2SAv9zzVWFcFQzYkcs3VYx/ha8 n2yQKLmR6WhEhDxkVwcFsuin3NYTx6VBu4j0ZH9OM4BTcR8KC8nTqFio6nlUqNl5HrwxPhiu4 C9ijZ4hCDjU0qPaLqAzWgLjhAu6GIcFi37ZV0MBxg/CUYIGKxETEH3lAUVmAGaipv6lG7wpuW Kz5r11QZY9rc54qmdrDkLh6SBIkI2C81nT85/fdbVBXSJHI191wtl7i6RIfGMUfuVvs0jJSKD RpRpxAJs+3HkVCwfFBEKz65wl6oon5qT9WYc1yn0xqBqRhEdmy0c6xSLsqaAWdmhv+vYrKHnl JnD8vbeaH7RMGfSOjlDiIl1lVgIer0E/RAcwqWlaBOpWqiXVdCKdU4byhAc0vIy2FE+UupWCN qrfE9fOIvLeOYNHRzFAKPi2JHnLrhoVZcw4mNr5FwdF/Z0blUDr0IiVC9BOfgGoBarxSCIAG9 kvzrfCLDBF8rQfDQRCzbFNMd0V7SgNEhz5e1c9wy6+tbVp4lLt6L7BPVa07hthciXQ+iLQynl EkQPp1yu1I7bSX77qamxRxRHY8/HOXQYzPRyaxMAFnp4qC1pn0all Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 28, 2020 at 12:05 AM Peilin Ye wrote: > > On Mon, Jul 27, 2020 at 04:16:08PM +0300, Dan Carpenter wrote: > > drivers/char/hpet.c:675 hpet_ioctl() warn: check that 'info' doesn't leak information (struct has a hole after 'hi_timer') > > This one seems like a false positive. > > drivers/char/hpet.c:670: > > mutex_lock(&hpet_mutex); > err = hpet_ioctl_common(file->private_data, cmd, arg, &info); > mutex_unlock(&hpet_mutex); > > if ((cmd == HPET_INFO) && !err && > (copy_to_user((void __user *)arg, &info, sizeof(info)))) > err = -EFAULT; > > `info` is only being copied to userspace when `cmd` is `HPET_INFO`. > However, hpet_ioctl_common() is already doing memset() on `info` in > `case HPET_INFO`: > > drivers/char/hpet.c:612: > > case HPET_INFO: > { > memset(info, 0, sizeof(*info)); > ^^^^^^ Yes, makes sense. Arnd