From bdc00039fd1bc1ebc9f7bebc75b13a81cd2e01bb Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 14 Jun 2023 16:05:39 +0300 Subject: [PATCH] media: mediatek: vcodec: fix potential double free [ Upstream commit be40f524b6edac4fb9a98ef79620fd9b9497a998 ] The "lat_buf->private_data" needs to be set to NULL to prevent a double free. How this would happen is if vdec_msg_queue_init() failed twice in a row and on the second time it failed earlier than on the first time. The vdec_msg_queue_init() function has a loop which does: for (i = 0; i < NUM_BUFFER_COUNT; i++) { Each iteration initializes one element in the msg_queue->lat_buf[] array and then the clean up function vdec_msg_queue_deinit() frees each element of the msg_queue->lat_buf[] array. This clean up code relies on the assumption that every element is either initialized or zeroed. Leaving a freed pointer which is non-zero breaks the assumption. Fixes: b199fe46f35c ("media: mtk-vcodec: Add msg queue feature for lat and core architecture") Signed-off-by: Dan Carpenter Reviewed-by: Nicolas Dufresne Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c b/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c index 03f8d7c..675f628 100644 --- a/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c +++ b/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c @@ -246,6 +246,7 @@ void vdec_msg_queue_deinit(struct vdec_msg_queue *msg_queue, mtk_vcodec_mem_free(ctx, mem); kfree(lat_buf->private_data); + lat_buf->private_data = NULL; } } -- 2.7.4