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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 54E07C2B9F4 for ; Tue, 15 Jun 2021 02:48:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30FB9611CE for ; Tue, 15 Jun 2021 02:48:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231145AbhFOCuX (ORCPT ); Mon, 14 Jun 2021 22:50:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229609AbhFOCtk (ORCPT ); Mon, 14 Jun 2021 22:49:40 -0400 Received: from mail-io1-xd36.google.com (mail-io1-xd36.google.com [IPv6:2607:f8b0:4864:20::d36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC846C0613A2 for ; Mon, 14 Jun 2021 19:47:34 -0700 (PDT) Received: by mail-io1-xd36.google.com with SMTP id 5so41791652ioe.1 for ; Mon, 14 Jun 2021 19:47:34 -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:mime-version :content-transfer-encoding; bh=XZngOmx3QZGSGE9q4/ABb06fw8+v1CSMYNte3U/V958=; b=j8BK1QDugcRXfg29Tqm6PhfSwlMgaC9EAqEaNluYMNCwd1ZYqElpq+kpbUktZ/urN4 MVFmsPENeAISNrJygUJCEH0UF3af93a34tumnmJViTDG/YGE/wodIWkh6IlvmCndB6+C dhDr528Ave7TwpBKkGjCQI5PK87kyPYmJvipI4DE38MSn+6feAKYNBkQV19h8yNjhNDr UYugo4buc+C0+WvrHfvDhza6lHEJ+JjmM2oqHjcwqmDbG1d19wnfbfgHbu/EGX3jc2Tu jTh8f5lXw1t0Dqjad76TQQ7B/0slKvtYlcdMqP/585LM2WdakYuYfAYdSziFLM0+kJIK /K5g== 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:mime-version :content-transfer-encoding; bh=XZngOmx3QZGSGE9q4/ABb06fw8+v1CSMYNte3U/V958=; b=o9YwIkbHJiOccdunhetULPPy68cl+982mgwJh/+CNAErQr49gogDsGGNmoGPXo+lU8 LWNzo+8GELTy1eN7YPGMX3BLKV1vzQZf4WK6qe2aiL9lQo+0KlW5LwqDzS373yuLiPp3 qN1OVLJtXlI5rTcVdcxQzy3ruv1MQAy0JZIJutM2rVMoMUXXBtKsRP2nFxhVdjNVk6/d 5MMWmOwkRfVnDKTDIJkSHS+uOtli5zCTamKq/VKhgQ9FpYO0OUeELcN5p/nJLIECtrqU sjLcX82y71PVWgKyVd4UhQh1ZKispDBcha94fzLpzg8Bfnb6D74iHr81flxJ7FcaF4h0 DEEw== X-Gm-Message-State: AOAM532QB/zCk9jH+iSQx6iU1Zz+j+1Zo9MH5BOh3ONDC5DMRl2h+qYt fN+2wqkr7KimscWvGL2AWJdwx6ERhyTK4YM6WEg= X-Google-Smtp-Source: ABdhPJwkiRcyYOeOqxFuMqJ+7O0OK1G86N3d9NPQLqADbQgmmfevSGkqOf0Dpo41Ig68e77DvD7ZZA== X-Received: by 2002:a63:ce07:: with SMTP id y7mr3664904pgf.249.1623724650822; Mon, 14 Jun 2021 19:37:30 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id b133sm14102623pfb.36.2021.06.14.19.37.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Jun 2021 19:37:30 -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 Cc: Desmond Cheong Zhi Xi , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org, emil.l.velikov@gmail.com Subject: [PATCH v2 0/2] drm: Address potential UAF bugs with drm_master ptrs Date: Tue, 15 Jun 2021 10:36:43 +0800 Message-Id: <20210615023645.6535-1-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch series addresses potential use-after-free errors when dereferencing pointers to struct drm_master. These were identified after one such bug was caught by Syzbot in drm_getunique(): https://syzkaller.appspot.com/bug?id=148d2f1dfac64af52ffd27b661981a540724f803 The series is broken up into two patches: 1. Implement a locked version of drm_is_current_master() function that's used within drm_auth.c 2. Identify areas in drm_lease.c where pointers to struct drm_master are dereferenced, and ensure that the master pointers are protected by a mutex Change in v2: - Patch 2: Move the lock and assignment before the DRM_DEBUG_LEASE in drm_mode_get_lease_ioctl, as suggested by Emil Velikov Desmond Cheong Zhi Xi (2): drm: Add a locked version of drm_is_current_master drm: Protect drm_master pointers in drm_lease.c drivers/gpu/drm/drm_auth.c | 23 ++++++++++++--- drivers/gpu/drm/drm_lease.c | 58 +++++++++++++++++++++++++++---------- 2 files changed, 62 insertions(+), 19 deletions(-) -- 2.25.1