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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 1A72FC3A5A9 for ; Mon, 4 May 2020 18:03:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8F98206B8 for ; Mon, 4 May 2020 18:03:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615421; bh=z4cqvnk6Rzpi/NGSkK4ma/fkQPm9mS7DduXFNAfNqs0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GZUj6jT+QHghGCXal2PGfvlnd5Qtwa4iXoVMmLu93Sh3LKl5uTd4ohKWcSw4GM9hK Gl+miud6sTsyJ235GLOfkmDHmBSOYIrCJKrACDNU6wRuJG+wnmh8m70Ic70ga2tH0J QlJCg5TkeVIyPU/hPEYWqafeGvP2urxrCPUDAByQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731551AbgEDSDk (ORCPT ); Mon, 4 May 2020 14:03:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:60824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731527AbgEDSDh (ORCPT ); Mon, 4 May 2020 14:03:37 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3CF4D205ED; Mon, 4 May 2020 18:03:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615415; bh=z4cqvnk6Rzpi/NGSkK4ma/fkQPm9mS7DduXFNAfNqs0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=seM5kZ3rDcr+QC/1bwHm1S7eGFvQt9JH711xHlKCTyiEdEB4J4VnE3o254YKPv9KB ZFHeXSHEdrXpKz7toBWhf+r7/v8PRpTv6VJDwqbHXMJl3Ygl6l8I8UOjDIg4rDuBZj PQGaNnOt4axlIOveUZVkhA9N/f5jz1T0XKjQpZHg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vasily Averin , Gerd Hoffmann Subject: [PATCH 5.4 06/57] drm/qxl: qxl_release use after free Date: Mon, 4 May 2020 19:57:10 +0200 Message-Id: <20200504165457.134532238@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200504165456.783676004@linuxfoundation.org> References: <20200504165456.783676004@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vasily Averin commit 933db73351d359f74b14f4af095808260aff11f9 upstream. qxl_release should not be accesses after qxl_push_*_ring_release() calls: userspace driver can process submitted command quickly, move qxl_release into release_ring, generate interrupt and trigger garbage collector. It can lead to crashes in qxl driver or trigger memory corruption in some kmalloc-192 slab object Gerd Hoffmann proposes to swap the qxl_release_fence_buffer_objects() + qxl_push_{cursor,command}_ring_release() calls to close that race window. cc: stable@vger.kernel.org Fixes: f64122c1f6ad ("drm: add new QXL driver. (v1.4)") Signed-off-by: Vasily Averin Link: http://patchwork.freedesktop.org/patch/msgid/fa17b338-66ae-f299-68fe-8d32419d9071@virtuozzo.com Signed-off-by: Gerd Hoffmann Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/qxl/qxl_cmd.c | 5 ++--- drivers/gpu/drm/qxl/qxl_display.c | 6 +++--- drivers/gpu/drm/qxl/qxl_draw.c | 2 +- drivers/gpu/drm/qxl/qxl_ioctl.c | 5 +---- 4 files changed, 7 insertions(+), 11 deletions(-) --- a/drivers/gpu/drm/qxl/qxl_cmd.c +++ b/drivers/gpu/drm/qxl/qxl_cmd.c @@ -500,8 +500,8 @@ int qxl_hw_surface_alloc(struct qxl_devi /* no need to add a release to the fence for this surface bo, since it is only released when we ask to destroy the surface and it would never signal otherwise */ - qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false); qxl_release_fence_buffer_objects(release); + qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false); surf->hw_surf_alloc = true; spin_lock(&qdev->surf_id_idr_lock); @@ -543,9 +543,8 @@ int qxl_hw_surface_dealloc(struct qxl_de cmd->surface_id = id; qxl_release_unmap(qdev, release, &cmd->release_info); - qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false); - qxl_release_fence_buffer_objects(release); + qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false); return 0; } --- a/drivers/gpu/drm/qxl/qxl_display.c +++ b/drivers/gpu/drm/qxl/qxl_display.c @@ -523,8 +523,8 @@ static int qxl_primary_apply_cursor(stru cmd->u.set.visible = 1; qxl_release_unmap(qdev, release, &cmd->release_info); - qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false); qxl_release_fence_buffer_objects(release); + qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false); return ret; @@ -665,8 +665,8 @@ static void qxl_cursor_atomic_update(str cmd->u.position.y = plane->state->crtc_y + fb->hot_y; qxl_release_unmap(qdev, release, &cmd->release_info); - qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false); qxl_release_fence_buffer_objects(release); + qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false); if (old_cursor_bo != NULL) qxl_bo_unpin(old_cursor_bo); @@ -713,8 +713,8 @@ static void qxl_cursor_atomic_disable(st cmd->type = QXL_CURSOR_HIDE; qxl_release_unmap(qdev, release, &cmd->release_info); - qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false); qxl_release_fence_buffer_objects(release); + qxl_push_cursor_ring_release(qdev, release, QXL_CMD_CURSOR, false); } static void qxl_update_dumb_head(struct qxl_device *qdev, --- a/drivers/gpu/drm/qxl/qxl_draw.c +++ b/drivers/gpu/drm/qxl/qxl_draw.c @@ -243,8 +243,8 @@ void qxl_draw_dirty_fb(struct qxl_device } qxl_bo_kunmap(clips_bo); - qxl_push_command_ring_release(qdev, release, QXL_CMD_DRAW, false); qxl_release_fence_buffer_objects(release); + qxl_push_command_ring_release(qdev, release, QXL_CMD_DRAW, false); out_release_backoff: if (ret) --- a/drivers/gpu/drm/qxl/qxl_ioctl.c +++ b/drivers/gpu/drm/qxl/qxl_ioctl.c @@ -261,11 +261,8 @@ static int qxl_process_single_command(st apply_surf_reloc(qdev, &reloc_info[i]); } + qxl_release_fence_buffer_objects(release); ret = qxl_push_command_ring_release(qdev, release, cmd->type, true); - if (ret) - qxl_release_backoff_reserve_list(release); - else - qxl_release_fence_buffer_objects(release); out_free_bos: out_free_release: