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authorDoug Horn <doughorn@google.com>2020-10-02 11:50:44 -0700
committerDoug Horn <doughorn@google.com>2020-10-02 18:56:47 +0000
commit3778f56d2d210a167a29466e1ab047bb181903f5 (patch)
tree8f7901f3250dd59a3055b5350926cb53c3092c09
parentc1546a1afe5da165acee0f91ea4a9be31a97693c (diff)
downloadcuttlefish-modules-android11-5.4.tar.gz
FROMGIT: drm/virtio: Fix use after free in get_capset_info callback.android11-5.4
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. Bug: 166299146 Signed-off-by: Doug Horn <doughorn@google.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> (cherry picked from commit e219688fc5c3d0d9136f8d29d7e0498388f01440) Change-Id: I1ab01855152e12dc34c56f9c85d723c8e7f7780c
-rw-r--r--virtio_gpu/virtgpu_kms.c2
-rw-r--r--virtio_gpu/virtgpu_vq.c10
2 files changed, 9 insertions, 3 deletions
diff --git a/virtio_gpu/virtgpu_kms.c b/virtio_gpu/virtgpu_kms.c
index 01d6f62..88b16df 100644
--- a/virtio_gpu/virtgpu_kms.c
+++ b/virtio_gpu/virtgpu_kms.c
@@ -97,8 +97,10 @@ 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/virtio_gpu/virtgpu_vq.c b/virtio_gpu/virtgpu_vq.c
index 93b32ef..1b7f4e6 100644
--- a/virtio_gpu/virtgpu_vq.c
+++ b/virtio_gpu/virtgpu_vq.c
@@ -572,9 +572,13 @@ 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);
}