lkml.org 
[lkml]   [2007]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/3] security: allow capable check to permit mmap or low vm space
On Fri, 16 Nov 2007, Eric Paris wrote:

> On Sat, 2007-11-17 at 08:47 +1100, James Morris wrote:
> > On Fri, 16 Nov 2007, Eric Paris wrote:
> >
> > > On a kernel with CONFIG_SECURITY but without an LSM which implements
> > > security_file_mmap it is impossible for an application to mmap addresses
> > > lower than mmap_min_addr.
> >
> > Actually, should we be doing any checking in the dummy module, given that
> > it is not done with !CONFIG_SECURITY ?
>
> I'm not sure I understand the question. We already do a number of
> capable type security checks in dummy functions. See dummy_settime() as
> just one example.

I mean just in this case. If no mmap_min_addr check is done without
CONFIG_SECURITY, then perhaps none should be done in the dummy module,
i.e. preserving existing behavior. LSM is theoretically supposed to be
unnoticable from a behavioral pov unless a non-dummy module is loaded.

>
> If we have !CONFIG_SECURITY we don't have any security protections (how
> could we? we turned them off) so we don't get into dummy hooks. If we
> do checks or not in uncompiled code doesn't seem to me to matter.
>
> Maybe I'm just confused...
>
> -Eric
>

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

\
 
 \ /
  Last update: 2007-11-16 23:01    [W:0.054 / U:0.436 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site