Messages in this thread | | | Date | Tue, 21 Jul 2009 16:04:37 +0100 | From | Alan Cox <> | Subject | Re: [PATCH 1/2] VM/SELinux: require CAP_SYS_RAWIO for all mmap_zero operations |
| |
On Tue, 21 Jul 2009 10:41:58 -0400 Eric Paris <eparis@redhat.com> wrote:
> Currently non-SELinux systems need CAP_SYS_RAWIO for an application to mmap > the 0 page. On SELinux systems they need a specific SELinux permission, > but do not need CAP_SYS_RAWIO. This has proved to be a poor decision by > the SELinux team as, by default, SELinux users are logged in unconfined and > thus a malicious non-root has nothing stopping them from mapping the 0 page > of virtual memory.
So the poor decision is in fact that the SELinux users start as unconfined rather than taking away a few things like the the min map stuff which can then be given back to specific apps.
> On a non-SELinux system, a malicious non-root user is unable to do this, as > they need CAP_SYS_RAWIO. > > This patch checks CAP_SYS_RAWIO for all operations which attemt to map a > page below mmap_min_addr.
So "wine" now needs to run with CAP_SYS_RAWIO or you turn all the security off.
Am I missing something here, this "solution" sounds completely brain dead ?
Alan
| |