Merge tag 'misc-habanalabs-fixes-2020-07-19' of git://people.freedesktop.org/~gabbayo/linux into char-misc-linus

Oded writes:

This tag contains a single bug fix for 5.8-rc7:

- Check that an index is in valid range before using it to access an
  array. The index is received from the user. This is to prevent a
  possible out-of-bounds access error.

* tag 'misc-habanalabs-fixes-2020-07-19' of git://people.freedesktop.org/~gabbayo/linux:
  habanalabs: prevent possible out-of-bounds array access

1 files changed, 11 insertions, 3 deletions

diff --git a/drivers/misc/habanalabs/command_submission.c b/drivers/misc/habanalabs/command_submission.c
index b0f62cbbdc87..f3a8f113865d 100644
--- a/drivers/misc/habanalabs/command_submission.c
+++ b/drivers/misc/habanalabs/command_submission.c
@@ -499,11 +499,19 @@ static int validate_queue_index(struct hl_device *hdev,
 	struct asic_fixed_properties *asic = &hdev->asic_prop;
 	struct hw_queue_properties *hw_queue_prop;
 
+	/* This must be checked here to prevent out-of-bounds access to
+	 * hw_queues_props array
+	 */
+	if (chunk->queue_index >= HL_MAX_QUEUES) {
+		dev_err(hdev->dev, "Queue index %d is invalid\n",
+			chunk->queue_index);
+		return -EINVAL;
+	}
+
 	hw_queue_prop = &asic->hw_queues_props[chunk->queue_index];
 
-	if ((chunk->queue_index >= HL_MAX_QUEUES) ||
-			(hw_queue_prop->type == QUEUE_TYPE_NA)) {
-		dev_err(hdev->dev, "Queue index %d is invalid\n",
+	if (hw_queue_prop->type == QUEUE_TYPE_NA) {
+		dev_err(hdev->dev, "Queue index %d is not applicable\n",
 			chunk->queue_index);
 		return -EINVAL;
 	}