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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 DDF1AC43218 for ; Mon, 10 Jun 2019 21:18:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5AFE20859 for ; Mon, 10 Jun 2019 21:18:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="iOFhp97O" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389970AbfFJVSW (ORCPT ); Mon, 10 Jun 2019 17:18:22 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:33713 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728517AbfFJVSV (ORCPT ); Mon, 10 Jun 2019 17:18:21 -0400 Received: by mail-pg1-f193.google.com with SMTP id k187so5185800pga.0 for ; Mon, 10 Jun 2019 14:18:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=vsVuZqN3BZSGA+LoVgx6ta+tF2PXiYDgRAf6MbHU3GI=; b=iOFhp97OR2XlAA4aQQYWlKmqqKyQE7mzMS+NyecweCZB2em2RWpyOF7yGs/OR4EsPo HLRUd7mFxlWl/mhy46zcVHdx1fam2I7BLziF07sxeXDAmX7xJ84JATe1nfiqQpAWfxSH aTL2zNkINzYLA9wyQl5EnKhO2k505n8llkvpA= 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=vsVuZqN3BZSGA+LoVgx6ta+tF2PXiYDgRAf6MbHU3GI=; b=PqEqncrROwK8dCtALsA55+CHE7E5PrznUTb9uhcyrQF/tTmKUbpDZQsa0YzBhx1KUm xSJmrdKBnFFf3j4JKFddMkjx0c7rAResGb/UptGxouDF79jLW+5vaOhZQUzoI5b9H418 Q/u5UFfbUwZ9X2EsOQxfEt6ypCuxf1Q5SDl/7uOePDZ1KdT2vxWiIuZKrv8la2bvtQ+U pxWgWPk/6tmMYhOwLHX1ylsBK9lF/h0G1xsmc8C4bvjneMYbFfugKEdm0NRZYiDqTFrv gckz1FFISRsffLufQYQnkB086qgGLtjg/KowB6z1oziUsQxDZGvzhH+OJ9ppQJt6aP6N UbrA== X-Gm-Message-State: APjAAAV1Npv+CTX6v8MkjfdF1kT02iD3pC+KX3o/PdnIgrNmlzvPpjyr dHIEclU3vNNJXBTRfJZIM27WVA== X-Google-Smtp-Source: APXvYqyAAVeRLFb2ZVyVA/0TT4TC0xtqnzO+EKpJMFECU/BWdHQEiQ+mA4zE+9LfkIxP0C4B1c4e9Q== X-Received: by 2002:aa7:8188:: with SMTP id g8mr26139750pfi.221.1560201500417; Mon, 10 Jun 2019 14:18:20 -0700 (PDT) Received: from localhost ([2620:15c:202:1:e9ae:bd45:1bd9:e60d]) by smtp.gmail.com with ESMTPSA id z15sm10573320pge.40.2019.06.10.14.18.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 10 Jun 2019 14:18:19 -0700 (PDT) From: davidriley@chromium.org To: Gerd Hoffmann , dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Cc: David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org, David Riley Subject: [PATCH v2 1/4] drm/virtio: Ensure cached capset entries are valid before copying. Date: Mon, 10 Jun 2019 14:18:07 -0700 Message-Id: <20190610211810.253227-2-davidriley@chromium.org> X-Mailer: git-send-email 2.22.0.rc2.383.gf4fbbf30c2-goog In-Reply-To: <20190605234423.11348-1-davidriley@chromium.org> References: <20190605234423.11348-1-davidriley@chromium.org> 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: David Riley virtio_gpu_get_caps_ioctl could return success with invalid data if a second caller to the function occurred after the entry was created in virtio_gpu_cmd_get_capset but prior to the virtio_gpu_cmd_capset_cb callback being called. This could leak contents of memory as well since the caps_cache allocation is done without zeroing. Signed-off-by: David Riley --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index 949a264985fc..88c1ed57a3c5 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -526,7 +526,6 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, list_for_each_entry(cache_ent, &vgdev->cap_cache, head) { if (cache_ent->id == args->cap_set_id && cache_ent->version == args->cap_set_ver) { - ptr = cache_ent->caps_cache; spin_unlock(&vgdev->display_info_lock); goto copy_exit; } @@ -537,6 +536,7 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, virtio_gpu_cmd_get_capset(vgdev, found_valid, args->cap_set_ver, &cache_ent); +copy_exit: ret = wait_event_timeout(vgdev->resp_wq, atomic_read(&cache_ent->is_valid), 5 * HZ); if (!ret) @@ -544,7 +544,6 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, ptr = cache_ent->caps_cache; -copy_exit: if (copy_to_user((void __user *)(unsigned long)args->addr, ptr, size)) return -EFAULT; -- 2.22.0.rc2.383.gf4fbbf30c2-goog