Re: KASAN: use-after-free Read in xlog_alloc_log

From: Christoph Hellwig
Date: Thu Jun 27 2019 - 09:52:34 EST


On Thu, Jun 27, 2019 at 04:06:54AM -0700, Christoph Hellwig wrote:
> It seems like this is the xlog_alloc_log error path. We didn't
> really change anything in the circular ioclogs queue handling, so
> maybe thish has been there before, but xfs_buf wasn't wired up to
> kasan to catch it?
>
> Either way I suspect the right thing to do is to replace the list
> with an array based lookup. I'll look into that, maybe a reproducer
> appears until then.

Actually, the iclog allocations are obviously too small. A patch will
be on its way soon.