[PATCH AUTOSEL 5.4 05/17] habanalabs: prevent possible out-of-bounds array access

[Sasha Levin]

From: Oded Gabbay <oded.gabbay@xxxxxxxxx>

[ Upstream commit cea7a0449ea3fa4883bf5dc8397f000d6b67d6cd ]

Queue index is received from the user. Therefore, we must validate it
before using it to access the queue props array.

Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
Reviewed-by: Tomer Tayar <ttayar@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/misc/habanalabs/command_submission.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/habanalabs/command_submission.c b/drivers/misc/habanalabs/command_submission.c
index 447f307ef4d6f..ef95ee33cea40 100644
--- a/drivers/misc/habanalabs/command_submission.c
+++ b/drivers/misc/habanalabs/command_submission.c
@@ -400,15 +400,23 @@ static struct hl_cb *validate_queue_index(struct hl_device *hdev,
 	/* Assume external queue */
 	*ext_queue = true;
 
-	hw_queue_prop = &asic->hw_queues_props[chunk->queue_index];
-
-	if ((chunk->queue_index >= HL_MAX_QUEUES) ||
-			(hw_queue_prop->type == QUEUE_TYPE_NA)) {
+	/* 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 NULL;
 	}
 
+	hw_queue_prop = &asic->hw_queues_props[chunk->queue_index];
+
+	if (hw_queue_prop->type == QUEUE_TYPE_NA) {
+		dev_err(hdev->dev, "Queue index %d is not applicable\n",
+			chunk->queue_index);
+		return -EINVAL;
+	}
+
 	if (hw_queue_prop->driver_only) {
 		dev_err(hdev->dev,
 			"Queue index %d is restricted for the kernel driver\n",
-- 
2.25.1