On Mon, Oct 17, 2011 at 02:07:10PM +0200, Jan Kiszka wrote: > On 2011-10-17 13:57, Michael S. Tsirkin wrote: > > On Mon, Oct 17, 2011 at 01:23:46PM +0200, Jan Kiszka wrote: > >> On 2011-10-17 13:10, Michael S. Tsirkin wrote: > >>> On Mon, Oct 17, 2011 at 11:27:40AM +0200, Jan Kiszka wrote: > >>>> Only accesses to the MSI-X table must trigger a call to > >>>> msix_handle_mask_update or a notifier invocation. > >>>> > >>>> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com> > >>> > >>> Why would msix_mmio_write be called on an access > >>> outside the table? > >> > >> Because it handles both the table and the PBA. > > > > Hmm. Interesting. Is there a bug in how we handle PBA > > updates then? If yes I'd like a separate patch for that > > to apply to the stable tree. > > I first thought it was a serious bug, but it just triggers if the guest > write to PBA (which is very uncommon) and that actually triggers any > spurious out-of-bounds vector injection. Highly unlikely.
Yes guests don't really use PBA ATM. But is there something bad a malicious guest can do? For example, what if msix_clr_pending gets invoked with this huge vector value? It does seem serious ... > > > > BTW, this code will go away if PBA can get stored separately? > > Hmm - yeah, true. Likely it's moot to discuss this change then. > > Jan > > -- > Siemens AG, Corporate Technology, CT T DE IT 1 > Corporate Competence Center Embedded Linux
