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authorVasily Averin <vvs@virtuozzo.com>2020-04-29 12:01:24 +0300
committerGerd Hoffmann <kraxel@redhat.com>2020-04-29 13:21:34 +0200
commit933db73351d359f74b14f4af095808260aff11f9 (patch)
tree1fe36df154fb79400c27cd3c02a22922348788dc
parent5b5703dbafae74adfbe298a56a81694172caf5e6 (diff)
downloadlinux-stericsson-933db73351d359f74b14f4af095808260aff11f9.tar.gz
drm/qxl: qxl_release use after free
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 <vvs@virtuozzo.com> Link: http://patchwork.freedesktop.org/patch/msgid/fa17b338-66ae-f299-68fe-8d32419d9071@virtuozzo.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
-rw-r--r--drivers/gpu/drm/qxl/qxl_cmd.c5
-rw-r--r--drivers/gpu/drm/qxl/qxl_display.c6
-rw-r--r--drivers/gpu/drm/qxl/qxl_draw.c2
-rw-r--r--drivers/gpu/drm/qxl/qxl_ioctl.c5
4 files changed, 7 insertions, 11 deletions
diff --git a/drivers/gpu/drm/qxl/qxl_cmd.c b/drivers/gpu/drm/qxl/qxl_cmd.c
index fa8762d15d0f..05863b253d68 100644
--- 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_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);
@@ -543,9 +543,8 @@ 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 09583a08e141..91f398d51cfa 100644
--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@@ -510,8 +510,8 @@ 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;
@@ -652,8 +652,8 @@ 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 != NULL)
qxl_bo_unpin(old_cursor_bo);
@@ -700,8 +700,8 @@ 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 void qxl_update_dumb_head(struct qxl_device *qdev,
diff --git a/drivers/gpu/drm/qxl/qxl_draw.c b/drivers/gpu/drm/qxl/qxl_draw.c
index f8776d60d08e..3599db096973 100644
--- 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 *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)
diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c b/drivers/gpu/drm/qxl/qxl_ioctl.c
index 8117a45b3610..72f3f1bbb40c 100644
--- 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(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: