From patchwork Tue Oct 21 10:50:36 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5117491 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 155F9C11AC for ; Tue, 21 Oct 2014 11:34:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3613C2010F for ; Tue, 21 Oct 2014 11:34:22 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3D71620107 for ; Tue, 21 Oct 2014 11:34:21 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 83481F20; Tue, 21 Oct 2014 11:05:45 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 99156B79 for ; Tue, 21 Oct 2014 11:05:44 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id C11DA2010C for ; Tue, 21 Oct 2014 11:05:43 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 21 Oct 2014 04:05:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617796131" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:05:42 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:50:36 +0800 Message-Id: <1413889294-31328-437-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Subject: [LTSI-dev] [PATCH 0436/1094] drm: Break out ioctl permission check to a separate function v2 X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Thomas Hellstrom Helps reviewing and understanding these checks. v2: Remove misplaced newlines. Signed-off-by: Thomas Hellstrom Reviewed-by: David Herrmann (cherry picked from commit c2667355619572c9324916b62b4f6608a56de031) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/drm_drv.c | 113 ++++++++++++++++++++++++++++++--------------- 1 file changed, 75 insertions(+), 38 deletions(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index ec651be..05e3053 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -286,6 +286,44 @@ static int drm_version(struct drm_device *dev, void *data, } /** + * drm_ioctl_permit - Check ioctl permissions against caller + * + * @flags: ioctl permission flags. + * @file_priv: Pointer to struct drm_file identifying the caller. + * + * Checks whether the caller is allowed to run an ioctl with the + * indicated permissions. If so, returns zero. Otherwise returns an + * error code suitable for ioctl return. + */ +static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv) +{ + /* ROOT_ONLY is only for CAP_SYS_ADMIN */ + if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN))) + return -EACCES; + + /* AUTH is only for authenticated or render client */ + if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) && + !file_priv->authenticated)) + return -EACCES; + + /* MASTER is only for master */ + if (unlikely((flags & DRM_MASTER) && !file_priv->is_master)) + return -EACCES; + + /* Control clients must be explicitly allowed */ + if (unlikely(!(flags & DRM_CONTROL_ALLOW) && + file_priv->minor->type == DRM_MINOR_CONTROL)) + return -EACCES; + + /* Render clients must be explicitly allowed */ + if (unlikely(!(flags & DRM_RENDER_ALLOW) && + drm_is_render_client(file_priv))) + return -EACCES; + + return 0; +} + +/** * Called whenever a process performs an ioctl on /dev/drm. * * \param inode device inode. @@ -350,52 +388,51 @@ long drm_ioctl(struct file *filp, /* Do not trust userspace, use our own definition */ func = ioctl->func; - if (!func) { + if (unlikely(!func)) { DRM_DEBUG("no function\n"); retcode = -EINVAL; - } else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) || - ((ioctl->flags & DRM_AUTH) && !drm_is_render_client(file_priv) && !file_priv->authenticated) || - ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) || - (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL)) || - (!(ioctl->flags & DRM_RENDER_ALLOW) && drm_is_render_client(file_priv))) { - retcode = -EACCES; - } else { - if (cmd & (IOC_IN | IOC_OUT)) { - if (asize <= sizeof(stack_kdata)) { - kdata = stack_kdata; - } else { - kdata = kmalloc(asize, GFP_KERNEL); - if (!kdata) { - retcode = -ENOMEM; - goto err_i1; - } - } - if (asize > usize) - memset(kdata + usize, 0, asize - usize); - } + goto err_i1; + } - if (cmd & IOC_IN) { - if (copy_from_user(kdata, (void __user *)arg, - usize) != 0) { - retcode = -EFAULT; + retcode = drm_ioctl_permit(ioctl->flags, file_priv); + if (unlikely(retcode)) + goto err_i1; + + if (cmd & (IOC_IN | IOC_OUT)) { + if (asize <= sizeof(stack_kdata)) { + kdata = stack_kdata; + } else { + kdata = kmalloc(asize, GFP_KERNEL); + if (!kdata) { + retcode = -ENOMEM; goto err_i1; } - } else - memset(kdata, 0, usize); - - if (ioctl->flags & DRM_UNLOCKED) - retcode = func(dev, kdata, file_priv); - else { - mutex_lock(&drm_global_mutex); - retcode = func(dev, kdata, file_priv); - mutex_unlock(&drm_global_mutex); } + if (asize > usize) + memset(kdata + usize, 0, asize - usize); + } - if (cmd & IOC_OUT) { - if (copy_to_user((void __user *)arg, kdata, - usize) != 0) - retcode = -EFAULT; + if (cmd & IOC_IN) { + if (copy_from_user(kdata, (void __user *)arg, + usize) != 0) { + retcode = -EFAULT; + goto err_i1; } + } else + memset(kdata, 0, usize); + + if (ioctl->flags & DRM_UNLOCKED) + retcode = func(dev, kdata, file_priv); + else { + mutex_lock(&drm_global_mutex); + retcode = func(dev, kdata, file_priv); + mutex_unlock(&drm_global_mutex); + } + + if (cmd & IOC_OUT) { + if (copy_to_user((void __user *)arg, kdata, + usize) != 0) + retcode = -EFAULT; } err_i1: