From patchwork Thu Jul 22 09:29:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Desmond Cheong Zhi Xi X-Patchwork-Id: 12393605 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=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 726B4C6377D for ; Thu, 22 Jul 2021 09:30:14 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 431496120C for ; Thu, 22 Jul 2021 09:30:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 431496120C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AA8806EE7C; Thu, 22 Jul 2021 09:30:13 +0000 (UTC) Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by gabe.freedesktop.org (Postfix) with ESMTPS id C7A296EE7C; Thu, 22 Jul 2021 09:30:11 +0000 (UTC) Received: by mail-pl1-x62d.google.com with SMTP id n11so3787738plc.2; Thu, 22 Jul 2021 02:30:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RSgVdB0+HpET8iLINuWOoeOWDDxUJjmmluxZNEz35KA=; b=o6LJ/myMP6JO8ChH8dYoqq21TZnuVfWqQC7aMNZVbEwvgt/wmupSJe5X7mUycZZ1OP wZUOpxPzR0Di4iK476owf2txOnd8aRvZIuWOSyNSQwF8qAfJx1gZjc1rqQNENDcoU4k8 pWfm16Rm2AyVdjC+e3kTofDMg7W/f1X4eU9NPEhv7mUcvN6ebC/kCdQLgGMJIgNOCd38 Z79Cpgk8vmBkJLmcW9tTTfCW8TJv/6nRrpzuj2HycvK3LMZlVo0xpmCpHif6k1kmeqBf /hzT0Pmizi11dqx4L91lE1OKq6ULDL3w/A5pjP58k83vlOPYfDR9I9UDXt06Iw0JzA4O hv7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RSgVdB0+HpET8iLINuWOoeOWDDxUJjmmluxZNEz35KA=; b=ompWVo1nAMaZPZ9ck8m/pAr5jcWYm+23OvsMO0DYy95WPdzNSWicw07M99kOXEjF4I 8RwKS80tqXJFJFN46gg+DdVpPSqvlLOdtM0R2I7fOgiHXbMqKkKIgBRAn2UcFA1ocfj9 aFDyy0xPSNlLV1dUt23h2ip0GsUhCKuJI/bVaBovHscBnAWJoGSlOcyQln9bcBkL5WBh IH070SNaVPVz/2X24dI9J9ZujqL9trlGsupK/JwPVXJsCWS3lzNKkWtqJS5IH7uwGWnx WXp4nE7Sq3crMRkkMxpUgDD/jHEZy1Vi6JZHAC1OIFmJ/lNK4sRgpWUfL61KOru1L6G+ apzA== X-Gm-Message-State: AOAM531cam2O4Ig1PV3/g2ha92gkAMxGn3Z+X55M7O3OIzMoTruvp24f aq3t73qyLe9VGLVTBz9cWgw= X-Google-Smtp-Source: ABdhPJyscK7c550TzHfpDv1WRnYYvoBsSoBWYdMCW0natilUebpT1uRY7os1lbemOjfZnuzWFb0RqA== X-Received: by 2002:a05:6a00:2306:b029:331:ebe8:a4b4 with SMTP id h6-20020a056a002306b0290331ebe8a4b4mr39978184pfh.15.1626946211504; Thu, 22 Jul 2021 02:30:11 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id q5sm1069592pjo.7.2021.07.22.02.30.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Jul 2021 02:30:11 -0700 (PDT) From: Desmond Cheong Zhi Xi To: linux-graphics-maintainer@vmware.com, zackr@vmware.com, airlied@linux.ie, daniel@ffwll.ch, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de Subject: [PATCH 1/3] drm: use the lookup lock in drm_is_current_master Date: Thu, 22 Jul 2021 17:29:27 +0800 Message-Id: <20210722092929.244629-2-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210722092929.244629-1-desmondcheongzx@gmail.com> References: <20210722092929.244629-1-desmondcheongzx@gmail.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gregkh@linuxfoundation.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter , skhan@linuxfoundation.org, Desmond Cheong Zhi Xi , linux-kernel-mentees@lists.linuxfoundation.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Inside drm_is_current_master, using the outer drm_device.master_mutex to protect reads of drm_file.master makes the function prone to creating lock hierarchy inversions. Instead, we can use the drm_file.master_lookup_lock that sits at the bottom of the lock hierarchy. Reported-by: Daniel Vetter Signed-off-by: Desmond Cheong Zhi Xi Reviewed-by: Daniel Vetter Signed-off-by: Peter Zijlstra (Intel) --- drivers/gpu/drm/drm_auth.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index f00354bec3fb..9c24b8cc8e36 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -63,8 +63,9 @@ static bool drm_is_current_master_locked(struct drm_file *fpriv) { - lockdep_assert_held_once(&fpriv->minor->dev->master_mutex); - + /* Either drm_device.master_mutex or drm_file.master_lookup_lock + * should be held here. + */ return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master; } @@ -82,9 +83,9 @@ bool drm_is_current_master(struct drm_file *fpriv) { bool ret; - mutex_lock(&fpriv->minor->dev->master_mutex); + spin_lock(&fpriv->master_lookup_lock); ret = drm_is_current_master_locked(fpriv); - mutex_unlock(&fpriv->minor->dev->master_mutex); + spin_unlock(&fpriv->master_lookup_lock); return ret; } From patchwork Thu Jul 22 09:29:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Desmond Cheong Zhi Xi X-Patchwork-Id: 12393607 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=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 88AF0C63798 for ; Thu, 22 Jul 2021 09:30:19 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 560E46120C for ; 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Thu, 22 Jul 2021 02:30:16 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id q5sm1069592pjo.7.2021.07.22.02.30.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Jul 2021 02:30:16 -0700 (PDT) From: Desmond Cheong Zhi Xi To: linux-graphics-maintainer@vmware.com, zackr@vmware.com, airlied@linux.ie, daniel@ffwll.ch, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de Subject: [PATCH 2/3] drm: clarify lifetime/locking for drm_master's lease fields Date: Thu, 22 Jul 2021 17:29:28 +0800 Message-Id: <20210722092929.244629-3-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210722092929.244629-1-desmondcheongzx@gmail.com> References: <20210722092929.244629-1-desmondcheongzx@gmail.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gregkh@linuxfoundation.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, skhan@linuxfoundation.org, Desmond Cheong Zhi Xi , linux-kernel-mentees@lists.linuxfoundation.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" In particular, we make it clear that &drm_device.mode_config.idr_mutex protects the lease idr and list structures for drm_master. The lessor field itself doesn't need to be protected as it doesn't change after it's set in drm_lease_create. Additionally, we add descriptions for the lifetime of lessors and leases to make it easier to reason about them. Signed-off-by: Desmond Cheong Zhi Xi Reviewed-by: Daniel Vetter --- include/drm/drm_auth.h | 62 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 51 insertions(+), 11 deletions(-) diff --git a/include/drm/drm_auth.h b/include/drm/drm_auth.h index f99d3417f304..c978c85464fa 100644 --- a/include/drm/drm_auth.h +++ b/include/drm/drm_auth.h @@ -58,12 +58,6 @@ struct drm_lock_data { * @refcount: Refcount for this master object. * @dev: Link back to the DRM device * @driver_priv: Pointer to driver-private information. - * @lessor: Lease holder - * @lessee_id: id for lessees. Owners always have id 0 - * @lessee_list: other lessees of the same master - * @lessees: drm_masters leasing from this one - * @leases: Objects leased to this drm_master. - * @lessee_idr: All lessees under this owner (only used where lessor == NULL) * * Note that master structures are only relevant for the legacy/primary device * nodes, hence there can only be one per device, not one per drm_minor. @@ -88,17 +82,63 @@ struct drm_master { struct idr magic_map; void *driver_priv; - /* Tree of display resource leases, each of which is a drm_master struct - * All of these get activated simultaneously, so drm_device master points - * at the top of the tree (for which lessor is NULL). Protected by - * &drm_device.mode_config.idr_mutex. + /** + * @lessor: + * + * Lease holder. The lessor does not change once it's set in + * drm_lease_create(). Each lessee holds a reference to its lessor that + * it releases upon being destroyed in drm_lease_destroy(). + * + * Display resource leases form a tree of &struct drm_master. All of + * these get activated simultaneously, so &drm_device.master + * points at the top of the tree (for which lessor is NULL). */ - struct drm_master *lessor; + + /** + * @lessee_id: + * + * ID for lessees. Owners always have ID 0. Protected by + * &drm_device.mode_config's &drm_mode_config.idr_mutex. + */ int lessee_id; + + /** + * @lessee_list: + * + * List of lessees of the same master. Protected by + * &drm_device.mode_config's &drm_mode_config.idr_mutex. + */ struct list_head lessee_list; + + /** + * @lessees: + * + * List of drm_masters leasing from this one. Protected by + * &drm_device.mode_config's &drm_mode_config.idr_mutex. + * + * This master cannot be destroyed unless this list is empty as lessors + * are referenced by all their lessees. + */ struct list_head lessees; + + /** + * @leases: + * + * Objects leased to this drm_master. Protected by + * &drm_device.mode_config's &drm_mode_config.idr_mutex. + * + * Objects are leased all together in drm_lease_create(), and are + * removed all together when the lease is revoked. + */ struct idr leases; + + /** + * @lessee_idr: + * + * All lessees under this owner (only used where lessor is NULL). + * Protected by &drm_device.mode_config's &drm_mode_config.idr_mutex. + */ struct idr lessee_idr; /* private: */ #if IS_ENABLED(CONFIG_DRM_LEGACY) From patchwork Thu Jul 22 09:29:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Desmond Cheong Zhi Xi X-Patchwork-Id: 12393609 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=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 ADE1AC63793 for ; 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Thu, 22 Jul 2021 02:30:21 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id q5sm1069592pjo.7.2021.07.22.02.30.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Jul 2021 02:30:21 -0700 (PDT) From: Desmond Cheong Zhi Xi To: linux-graphics-maintainer@vmware.com, zackr@vmware.com, airlied@linux.ie, daniel@ffwll.ch, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de Subject: [PATCH 3/3] drm/vmwgfx: fix potential UAF in vmwgfx_surface.c Date: Thu, 22 Jul 2021 17:29:29 +0800 Message-Id: <20210722092929.244629-4-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210722092929.244629-1-desmondcheongzx@gmail.com> References: <20210722092929.244629-1-desmondcheongzx@gmail.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gregkh@linuxfoundation.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, skhan@linuxfoundation.org, Desmond Cheong Zhi Xi , linux-kernel-mentees@lists.linuxfoundation.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" drm_file.master should be protected by either drm_device.master_mutex or drm_file.master_lookup_lock when being dereferenced. However, drm_master_get is called on unprotected file_priv->master pointers in vmw_surface_define_ioctl and vmw_gb_surface_define_internal. This is fixed by replacing drm_master_get with drm_file_get_master. Signed-off-by: Desmond Cheong Zhi Xi Reviewed-by: Daniel Vetter Reviewed-by: Zack Rusin --- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index 0eba47762bed..5d53a5f9d123 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -865,7 +865,7 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data, user_srf->prime.base.shareable = false; user_srf->prime.base.tfile = NULL; if (drm_is_primary_client(file_priv)) - user_srf->master = drm_master_get(file_priv->master); + user_srf->master = drm_file_get_master(file_priv); /** * From this point, the generic resource management functions @@ -1534,7 +1534,7 @@ vmw_gb_surface_define_internal(struct drm_device *dev, user_srf = container_of(srf, struct vmw_user_surface, srf); if (drm_is_primary_client(file_priv)) - user_srf->master = drm_master_get(file_priv->master); + user_srf->master = drm_file_get_master(file_priv); res = &user_srf->srf.res;