Re: [PATCH 1/4] module: add syscall to load module from fd

[Alon Ziv]

H. Peter Anvin <hpa <at> zytor.com> writes:
> > It is a bit more indirect, but also in practice it's a bit trickier than
> > that.  We need to ensure the memory doesn't change underneath us and
> > stays attached to that fd.  I can easily see that code slipping and
> > ending in an exploit.
> >
> > But that may be my irrational fear of the mm :)
> 
> You have to do the same thing with a file/file descriptor, I would think.
> 
> However, I keep wondering about the use case for this, as opposed to 
> signatures.

Two things:
1. finit_module() lets LSMs make decisions based on full information on the
   module to be loaded
2. On some systems (such as Chromium OS) we have a trusted root OS (e.g. the
   entire root filesystem is protected using dm-verity); requiring signatures
   on top of this is a waste of resources


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/