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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 5D3E3C433DF for ; Fri, 29 May 2020 00:35:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F34B2075F for ; Fri, 29 May 2020 00:35:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438127AbgE2Afe (ORCPT ); Thu, 28 May 2020 20:35:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728820AbgE2AfQ (ORCPT ); Thu, 28 May 2020 20:35:16 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69000C08C5CB; Thu, 28 May 2020 17:35:16 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.93 #3 (Red Hat Linux)) id 1jeSzR-00HFRU-Vs; Fri, 29 May 2020 00:35:14 +0000 From: Al Viro To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Ian Abbott Subject: [PATCH 09/10] comedi: do_cmd_ioctl(): lift copyin/copyout into the caller Date: Fri, 29 May 2020 01:35:12 +0100 Message-Id: <20200529003512.4110852-9-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200529003512.4110852-1-viro@ZenIV.linux.org.uk> References: <20200529003419.GX23230@ZenIV.linux.org.uk> <20200529003512.4110852-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro Signed-off-by: Al Viro --- drivers/staging/comedi/comedi_fops.c | 48 ++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 24 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index a40a865ed45c..f5ecfbfcdaf5 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1741,9 +1741,8 @@ static int __comedi_get_user_chanlist(struct comedi_device *dev, * possibly modified comedi_cmd structure (when -EAGAIN returned) */ static int do_cmd_ioctl(struct comedi_device *dev, - struct comedi_cmd __user *arg, void *file) + struct comedi_cmd *cmd, bool *copy, void *file) { - struct comedi_cmd cmd; struct comedi_subdevice *s; struct comedi_async *async; unsigned int __user *user_chanlist; @@ -1751,20 +1750,15 @@ static int do_cmd_ioctl(struct comedi_device *dev, lockdep_assert_held(&dev->mutex); - if (copy_from_user(&cmd, arg, sizeof(cmd))) { - dev_dbg(dev->class_dev, "bad cmd address\n"); - return -EFAULT; - } - - /* get the user's cmd and do some simple validation */ - ret = __comedi_get_user_cmd(dev, &cmd); + /* do some simple cmd validation */ + ret = __comedi_get_user_cmd(dev, cmd); if (ret) return ret; /* save user's chanlist pointer so it can be restored later */ - user_chanlist = (unsigned int __user *)cmd.chanlist; + user_chanlist = (unsigned int __user *)cmd->chanlist; - s = &dev->subdevices[cmd.subdev]; + s = &dev->subdevices[cmd->subdev]; async = s->async; /* are we locked? (ioctl lock) */ @@ -1780,13 +1774,13 @@ static int do_cmd_ioctl(struct comedi_device *dev, } /* make sure channel/gain list isn't too short */ - if (cmd.chanlist_len < 1) { + if (cmd->chanlist_len < 1) { dev_dbg(dev->class_dev, "channel/gain list too short %u < 1\n", - cmd.chanlist_len); + cmd->chanlist_len); return -EINVAL; } - async->cmd = cmd; + async->cmd = *cmd; async->cmd.data = NULL; /* load channel/gain list */ @@ -1798,15 +1792,11 @@ static int do_cmd_ioctl(struct comedi_device *dev, if (async->cmd.flags & CMDF_BOGUS || ret) { dev_dbg(dev->class_dev, "test returned %d\n", ret); - cmd = async->cmd; + *cmd = async->cmd; /* restore chanlist pointer before copying back */ - cmd.chanlist = (unsigned int __force *)user_chanlist; - cmd.data = NULL; - if (copy_to_user(arg, &cmd, sizeof(cmd))) { - dev_dbg(dev->class_dev, "fault writing cmd\n"); - ret = -EFAULT; - goto cleanup; - } + cmd->chanlist = (unsigned int __force *)user_chanlist; + cmd->data = NULL; + *copy = true; ret = -EAGAIN; goto cleanup; } @@ -2207,9 +2197,19 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, case COMEDI_CANCEL: rc = do_cancel_ioctl(dev, arg, file); break; - case COMEDI_CMD: - rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file); + case COMEDI_CMD: { + struct comedi_cmd cmd; + bool copy = false; + + if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) { + rc = -EFAULT; + break; + } + rc = do_cmd_ioctl(dev, &cmd, ©, file); + if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd))) + rc = -EFAULT; break; + } case COMEDI_CMDTEST: { struct comedi_cmd cmd; bool copy = false; -- 2.11.0