xen: patch with XSA-467

When setting up interrupt remapping for legacy PCI(-X) devices,
including PCI(-X) bridges, a lookup of the upstream bridge is required.
This lookup, itself involving acquiring of a lock, is done in a context
where acquiring that lock is unsafe. This can lead to a deadlock.

The passing through of certain kinds of devices to an unprivileged guest
can result in a Denial of Service (DoS) affecting the entire host.

Note: Normal usage of such devices by a privileged domain can also
      trigger the issue.  In such a scenario, the deadlock is not
      considered a security issue, but just a plain bug.

Systems with Intel IOMMU hardware (VT-d) are affected.  Systems using
AMD or non-x86 hardware are not affected.

Only systems where certain kinds of devices are passed through to an
unprivileged guest are vulnerable.

Signed-off-by: Fernando Rodrigues <alpha@sigmasquadron.net>

0 files changed, 0 insertions, 0 deletions