diff options
| author | Doug Horn <doughorn@google.com> | 2020-09-03 00:08:25 +0300 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2020-09-09 09:54:14 +0300 |
| commit | e219688fc5c3d0d9136f8d29d7e0498388f01440 (patch) | |
| tree | 5dec56331a6d437fcba1220979a6a82c6dfb3116 | |
| parent | 707d561f77b5e2a6f90c9786bee44ee7a8dedc7e (diff) | |
| download | linux-e219688fc5c3d0d9136f8d29d7e0498388f01440.tar.xz | |
Fix use after free in get_capset_info callback.
If a response to virtio_gpu_cmd_get_capset_info takes longer than
five seconds to return, the callback will access freed kernel memory
in vg->capsets.
Signed-off-by: Doug Horn <doughorn@google.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200902210847.2689-2-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_kms.c | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_vq.c | 10 |
2 files changed, 9 insertions, 3 deletions
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c index 75d0dc2f6d28..5ba389e0a02f 100644 --- a/drivers/gpu/drm/virtio/virtgpu_kms.c +++ b/drivers/gpu/drm/virtio/virtgpu_kms.c @@ -80,8 +80,10 @@ static void virtio_gpu_get_capsets(struct virtio_gpu_device *vgdev, vgdev->capsets[i].id > 0, 5 * HZ); if (ret == 0) { DRM_ERROR("timed out waiting for cap set %d\n", i); + spin_lock(&vgdev->display_info_lock); kfree(vgdev->capsets); vgdev->capsets = NULL; + spin_unlock(&vgdev->display_info_lock); return; } DRM_INFO("cap set %d: id %d, max-version %d, max-size %d\n", diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index c93c2db35aaf..7436705ba5a2 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -684,9 +684,13 @@ static void virtio_gpu_cmd_get_capset_info_cb(struct virtio_gpu_device *vgdev, int i = le32_to_cpu(cmd->capset_index); spin_lock(&vgdev->display_info_lock); - vgdev->capsets[i].id = le32_to_cpu(resp->capset_id); - vgdev->capsets[i].max_version = le32_to_cpu(resp->capset_max_version); - vgdev->capsets[i].max_size = le32_to_cpu(resp->capset_max_size); + if (vgdev->capsets) { + vgdev->capsets[i].id = le32_to_cpu(resp->capset_id); + vgdev->capsets[i].max_version = le32_to_cpu(resp->capset_max_version); + vgdev->capsets[i].max_size = le32_to_cpu(resp->capset_max_size); + } else { + DRM_ERROR("invalid capset memory."); + } spin_unlock(&vgdev->display_info_lock); wake_up(&vgdev->resp_wq); } |