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| author | Vasily Averin <vvs@virtuozzo.com> | 2020-04-29 11:01:24 +0200 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2020-04-29 13:21:34 +0200 |
| commit | 933db73351d359f74b14f4af095808260aff11f9 (patch) | |
| tree | 1fe36df154fb79400c27cd3c02a22922348788dc /drivers/gpu/drm/qxl/qxl_ioctl.c | |
| parent | drm/qxl: lost qxl_bo_kunmap_atomic_page in qxl_image_init_helper() (diff) | |
| download | linux-933db73351d359f74b14f4af095808260aff11f9.tar.xz linux-933db73351d359f74b14f4af095808260aff11f9.zip | |
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 '')
| -rw-r--r-- | drivers/gpu/drm/qxl/qxl_ioctl.c | 5 |
1 files changed, 1 insertions, 4 deletions
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: |