From: Dan Carpenter Date: Wed, 14 Jun 2023 13:05:39 +0000 (+0300) Subject: media: mediatek: vcodec: fix potential double free X-Git-Tag: v6.6-rc1~97^2~223 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=be40f524b6edac4fb9a98ef79620fd9b9497a998;p=thirdparty%2Fkernel%2Flinux.git media: mediatek: vcodec: fix potential double free 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 --- diff --git a/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c b/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c index 04e6dc6cfa1de..f2d21b5bc5c3a 100644 --- a/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c +++ b/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c @@ -231,6 +231,7 @@ 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; } if (msg_queue->wdma_addr.size)