diff options
| author | Vasily Averin <vvs@virtuozzo.com> | 2020-04-29 12:01:24 +0300 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2020-04-29 13:21:34 +0200 |
| commit | 933db73351d359f74b14f4af095808260aff11f9 (patch) | |
| tree | 1fe36df154fb79400c27cd3c02a22922348788dc /drivers/gpu/drm/qxl/qxl_draw.c | |
| parent | 5b5703dbafae74adfbe298a56a81694172caf5e6 (diff) | |
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>
Diffstat (limited to 'drivers/gpu/drm/qxl/qxl_draw.c')
| -rw-r--r-- | drivers/gpu/drm/qxl/qxl_draw.c | 2 |
1 files changed, 1 insertions, 1 deletions
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) |