From patchwork Thu Aug 26 02:01:16 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: 503553 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 0CE1DC43214 for ; Thu, 26 Aug 2021 02:02:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1E26610C8 for ; Thu, 26 Aug 2021 02:02:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237096AbhHZCDE (ORCPT ); Wed, 25 Aug 2021 22:03:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237024AbhHZCDC (ORCPT ); Wed, 25 Aug 2021 22:03:02 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F5ADC0613C1; Wed, 25 Aug 2021 19:02:16 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id u11-20020a17090adb4b00b00181668a56d6so1195447pjx.5; Wed, 25 Aug 2021 19:02:16 -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=Hm7YjUyiFZ/KTSC9DbXmgQsGRHrND7m8Eh1agHCitnc=; b=eL86sOSM38lNhD9QERUYW9QJOWqzwM9yMC5ODYSiS76jzKuzhpocylCwBl3NYLBrhn CeZZ4obH8pfh7ioTZINC44g6DS/7JTSqG0kgSxGe9myG/dr2y8wVsOgoBI+/pKmRnBeM I3kuQlSagQ+4bgPn4qboJAwIyFgI3YNHtEYvxollzFxBLnnpDmI8mUFXPVAMvkAjB15T 8BYytvAIw9PXoJ7uR0L0hE+3UX56DgQ39jwoAEkDoqWst2RDm09ZvG7KzJxL69ttDEfN 1moZPEAzMaCIbqb/GuJFOkzzdjqLI0J/MayaGM/DIJ+Il2kFxUyqRptnbPkIYceKYwfM hWdQ== 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=Hm7YjUyiFZ/KTSC9DbXmgQsGRHrND7m8Eh1agHCitnc=; b=DK0LBr/iGhfI9rmWFN1IJIM9iEIWFnFg5dY3TT/GbRNiT1sGF1V20NMqti5VgsRFDU DdaFhSCfa9VStQhr1ZNrhx3YDV1TpnYv9zKvhEBK8S3swlsqfBfyAxALqnf5FG4k+1DW /B5kLlmPL/VZhh+OXcs5lc9vlhiH8L+fk8+VE67VUCbO6DzUKAee4crIaRn00pbbat2L /hLjpNNf3ApI76HITvv5pPqBSt2QO0WeiXq7Um+cXqpc9nHKvxljA8Vk7fOBjgvkuPH7 cWT1eZpDd6OcJuNqEcxNcsqheQ/tPQCaAHOUb0PdvOXMD51RglDjLkhsUOLDhPAVvAY0 +ujg== X-Gm-Message-State: AOAM532uVt5rHgT3Jkw0iNTYYCOyjNB3jL8khFmZ4olir1aibF+U8dtT GINuACS2aI7wLb4GVjaT3aE= X-Google-Smtp-Source: ABdhPJxe7t5OmIkGit7oUHWuu+mWVsnNAK5sHRclsy4or+MfmMDi12IoLs2rUt7azoHz5WvKKkFx+w== X-Received: by 2002:a17:902:e891:b029:12d:6824:9d28 with SMTP id w17-20020a170902e891b029012d68249d28mr1344605plg.23.1629943335829; Wed, 25 Aug 2021 19:02:15 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id i11sm721973pjj.19.2021.08.25.19.02.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Aug 2021 19:02:15 -0700 (PDT) From: Desmond Cheong Zhi Xi To: maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@linux.ie, daniel@ffwll.ch, sumit.semwal@linaro.org, christian.koenig@amd.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, chris@chris-wilson.co.uk, ville.syrjala@linux.intel.com, matthew.auld@intel.com, dan.carpenter@oracle.com, tvrtko.ursulin@intel.com, matthew.d.roper@intel.com, lucas.demarchi@intel.com, karthik.b.s@intel.com, jose.souza@intel.com, manasi.d.navare@intel.com, airlied@redhat.com, aditya.swarup@intel.com, andrescj@chromium.org, linux-graphics-maintainer@vmware.com, zackr@vmware.com Cc: Desmond Cheong Zhi Xi , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: [PATCH v8 1/7] drm: fix null ptr dereference in drm_master_release Date: Thu, 26 Aug 2021 10:01:16 +0800 Message-Id: <20210826020122.1488002-2-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210826020122.1488002-1-desmondcheongzx@gmail.com> References: <20210826020122.1488002-1-desmondcheongzx@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org drm_master_release can be called on a drm_file without a master, which results in a null ptr dereference of file_priv->master->magic_map. The three cases are: 1. Error path in drm_open_helper drm_open(): drm_open_helper(): drm_master_open(): drm_new_set_master(); <--- returns -ENOMEM, drm_file.master not set drm_file_free(): drm_master_release(); <--- NULL ptr dereference (file_priv->master->magic_map) 2. Error path in mock_drm_getfile mock_drm_getfile(): anon_inode_getfile(); <--- returns error, drm_file.master not set drm_file_free(): drm_master_release(); <--- NULL ptr dereference (file_priv->master->magic_map) 3. In drm_client_close, as drm_client_open doesn't set up a master drm_file.master is set up in drm_open_helper through the call to drm_master_open, so we mirror it with a call to drm_master_release in drm_close_helper, and remove drm_master_release from drm_file_free to avoid the null ptr dereference. Signed-off-by: Desmond Cheong Zhi Xi --- drivers/gpu/drm/drm_file.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index ed25168619fc..90b62f360da1 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -282,9 +282,6 @@ void drm_file_free(struct drm_file *file) drm_legacy_ctxbitmap_flush(dev, file); - if (drm_is_primary_client(file)) - drm_master_release(file); - if (dev->driver->postclose) dev->driver->postclose(dev, file); @@ -305,6 +302,9 @@ static void drm_close_helper(struct file *filp) list_del(&file_priv->lhead); mutex_unlock(&dev->filelist_mutex); + if (drm_is_primary_client(file_priv)) + drm_master_release(file_priv); + drm_file_free(file_priv); }