Re: [PATCH] media:cec:fix double free and uaf issue when cancel data during noblocking

From: Xinghui Li
Date: Wed Jan 18 2023 - 23:58:02 EST


在 2023/1/18 18:18,“Hans Verkuil”<hverkuil-cisco@xxxxxxxxx <mailto:hverkuil-cisco@xxxxxxxxx>> 写入:

>...while this free is called if data->blocking is true. (see the 'if (!block) return 0;'
>further up).
Do you mean this code?

/* All done if we don't need to block waiting for completion */
if (!block)
return 0;
I notice this part code. But I'm not sure if 'block' will be modified in other sync operations.
So I sent this patch for community to review.

>So I have my doubts if this patch actually addresses the correct issue.
>Do you have an actual debug trace of the UAF? Or even better, code to reproduce
>this issue.

And we found this issue by the code scanning tool developed by loydlv and filtered from 200 issue by human.
So it could be the none-issue. If so, I hope I didn't waste too much of your time. __