Re: [PATCH] fs: don't let getdents return bogus names

[Pavel Machek]

On Mon 2018-07-16 20:56:57, Al Viro wrote:
> On Mon, Jul 16, 2018 at 09:48:43PM +0200, Jann Horn wrote:
> > When you e.g. run `find` on a directory for which getdents returns
> > "filenames" that contain slashes, `find` passes those "filenames" back to
> > the kernel, which then interprets them as paths. That could conceivably
> > cause userspace to do something bad when accessing something like an
> > untrusted USB stick, but I'm not aware of any specific example.
> > 
> > Instead of returning bogus filenames to userspace, return -EUCLEAN.
> 
> Because there's such a lot of userland code that expect and handles that
> error value...
> 
> I'm not sure if this mitigation is actually better than "just return it
> as-is", TBH.

Well, userspace should handle errors.. it may not understand what this
particular error means, but that's still better than risking issues
with / in path....

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Attachment: signature.asc
Description: Digital signature