From patchwork Mon May 4 11:38:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vasily Averin X-Patchwork-Id: 226452 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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_SANE_1 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 52FD2C47257 for ; Mon, 4 May 2020 11:38:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D90021835 for ; Mon, 4 May 2020 11:38:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728665AbgEDLiW (ORCPT ); Mon, 4 May 2020 07:38:22 -0400 Received: from relay.sw.ru ([185.231.240.75]:48014 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728698AbgEDLiW (ORCPT ); Mon, 4 May 2020 07:38:22 -0400 Received: from vvs-ws.sw.ru ([172.16.24.21]) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1jVZQQ-0002SH-QA; Mon, 04 May 2020 14:38:18 +0300 From: Vasily Averin Subject: [PATCH 4.14] drm/qxl: qxl_release use after free To: gregkh@linuxfoundation.org, stable@vger.kernel.org Cc: Gerd Hoffmann Message-ID: <050bf096-986a-6ee8-7bef-37a532cc1fcd@virtuozzo.com> Date: Mon, 4 May 2020 14:38:18 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 Content-Language: en-US Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org >From 933db73351d359f74b14f4af095808260aff11f9 Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Wed, 29 Apr 2020 12:01:24 +0300 Subject: drm/qxl: qxl_release use after free 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 backported to v4.14-stable Signed-off-by: Vasily Averin --- drivers/gpu/drm/qxl/qxl_cmd.c | 5 ++--- drivers/gpu/drm/qxl/qxl_display.c | 6 +++--- drivers/gpu/drm/qxl/qxl_draw.c | 8 ++++---- drivers/gpu/drm/qxl/qxl_ioctl.c | 5 +---- 4 files changed, 10 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/qxl/qxl_cmd.c b/drivers/gpu/drm/qxl/qxl_cmd.c index 3eb920851141..31fbeba1494d 100644 --- a/drivers/gpu/drm/qxl/qxl_cmd.c +++ b/drivers/gpu/drm/qxl/qxl_cmd.c @@ -532,8 +532,8 @@ int qxl_hw_surface_alloc(struct qxl_device *qdev, /* 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); @@ -575,9 +575,8 @@ int qxl_hw_surface_dealloc(struct qxl_device *qdev, 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; } diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c index 573bab222123..b209a25e307d 100644 --- a/drivers/gpu/drm/qxl/qxl_display.c +++ b/drivers/gpu/drm/qxl/qxl_display.c @@ -533,8 +533,8 @@ static int qxl_primary_apply_cursor(struct drm_plane *plane) 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; @@ -701,8 +701,8 @@ static void qxl_cursor_atomic_update(struct drm_plane *plane, 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) qxl_bo_unref(&old_cursor_bo); @@ -747,8 +747,8 @@ static void qxl_cursor_atomic_disable(struct drm_plane *plane, 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 int qxl_plane_prepare_fb(struct drm_plane *plane, diff --git a/drivers/gpu/drm/qxl/qxl_draw.c b/drivers/gpu/drm/qxl/qxl_draw.c index 4d8681e84e68..958d0d870c99 100644 --- a/drivers/gpu/drm/qxl/qxl_draw.c +++ b/drivers/gpu/drm/qxl/qxl_draw.c @@ -241,8 +241,8 @@ void qxl_draw_opaque_fb(const struct qxl_fb_image *qxl_fb_image, qxl_bo_physical_address(qdev, dimage->bo, 0); qxl_release_unmap(qdev, release, &drawable->release_info); - 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_free_palette: if (palette_bo) @@ -381,8 +381,8 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev, } 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) @@ -432,8 +432,8 @@ void qxl_draw_copyarea(struct qxl_device *qdev, drawable->u.copy_bits.src_pos.y = sy; qxl_release_unmap(qdev, release, &drawable->release_info); - 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_free_release: if (ret) @@ -476,8 +476,8 @@ void qxl_draw_fill(struct qxl_draw_fill *qxl_draw_fill_rec) qxl_release_unmap(qdev, release, &drawable->release_info); - 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_free_release: if (ret) diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c b/drivers/gpu/drm/qxl/qxl_ioctl.c index 31effed4a3c8..cede17585525 100644 --- a/drivers/gpu/drm/qxl/qxl_ioctl.c +++ b/drivers/gpu/drm/qxl/qxl_ioctl.c @@ -257,11 +257,8 @@ static int qxl_process_single_command(struct qxl_device *qdev, 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: