This is a note to let you know that I've just added the patch titled
media: mediatek: vcodec: fix potential double free
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-mediatek-vcodec-fix-potential-double-free.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 74d1c6b7bf11ed07f768c77438b4751b1754d348
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Wed Jun 14 16:05:39 2023 +0300
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 <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c b/drivers/media/platform/mediatek/vcodec/vdec_msg_queue.c
index 03f8d7cd8eddc..675f62814f94e 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;
}
}
