Re: [PATCH] cachefiles: fix out-of-bounds read in coherency trace

[Yichong Chen <chenyichong@uniontech.com>]

On Thu, Aug 27, 2026 at 08:31:18AM +0100, David Howells wrote:
> Thanks, but I have a patch for this.  See patch 9 here:
>
> https://lore.kernel.org/linux-fsdevel/20260825132045.1000787-1-dhowells@redhat.com/
>
> I don't want to call memcpy() like this just for the purposes of a tracepoint
> that is almost certainly not actually be active.
>
> You're also moving buf->content into a variable rather than using it directly
> - is there a reason for that?

Thanks for pointing me to your patch.

The local content variable was intended to avoid reading fields from the
xattr buffer on the getxattr failure path, where the buffer contents may
not be valid.

Your patch already handles the short auxiliary data case by making room for
the traced bytes and pre-clearing them, so please ignore my patch.  I'll
drop it on my side.

Thanks,
Yichong