On Mon, Jan 04, 2016 at 04:22:32PM +0000, David Vrabel wrote: > On 04/01/16 13:06, Marek Marczykowski-Górecki wrote: > > On Tue, Dec 22, 2015 at 10:06:25AM -0500, Eric Shelton wrote: > >> The XSA mentions that "PV frontend patches will be developed and > >> released (publicly) after the embargo date." Has anything been done > >> towards this that should also be incorporated into MiniOS? On a > >> system utilizing a "driver domain," where a backend is running on a > >> domain that is considered unprivileged and untrusted (such as the > >> example described in http://wiki.xenproject.org/wiki/Driver_Domain), > >> it seems XSA-155-style double fetch vulnerabilities in the frontends > >> are also a potential security concern, and should be eliminated. > >> However, perhaps that does not include pcifront, since pciback would > >> always be running in dom0. > > > > And BTW the same applies to Linux frontends, for which also I haven't seen > > any public development. In attachment my email to > > xen-security-issues-discuss list (sent during embargo), with patches > > attached there. I haven't got any response. > > There are no similar security concerns with frontends since they trust > the backend. > > I note that you say: > > "But in some cases (namely: if driver domains are in use), frontends > may be more trusted/privileged than backends." > > But this cannot be the case since the backend can always trivially DoS > the frontend by (for example) not unmapping grant references when > required by the protocol.
DoS is one thing, code execution is another. -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing?
pgpqsgrEMhRQd.pgp
Description: PGP signature
_______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
