Re: [PATCH 0/3] kernfs: Convert from strlcpy() to strscpy()

From: Kees Cook
Date: Mon Nov 27 2023 - 19:38:32 EST


On Mon, Nov 27, 2023 at 01:43:57PM +0000, Greg Kroah-Hartman wrote:
> On Thu, Nov 16, 2023 at 11:21:22AM -0800, Kees Cook wrote:
> > Hi,
> >
> > One of the last users of strlcpy() is kernfs, which has some complex
> > calling hierarchies that needed to be carefully examined. This series
> > refactors the strlcpy() calls into strscpy() calls, and bubbles up all
> > changes in return value checking for callers.
>
> Why not work instead to convert kernfs (and by proxy cgroups) to use the
> "safe" string functions based on seq_file? This should be a simpler
> patch series to review, and implement on a per-function basis, and then
> we would not have any string functions in kernfs anymore.

One thing at a time. :) This lets us finish the strlcpy() removal. But
yes, replacing all of kernfs/sysfs to pass a seq_buf instead of a char *
is on the list. :) I think I see a way to transition to it, too.

--
Kees Cook