[Qemu-commits] [qemu/qemu] 81b23e: xen: limit guest control of PCI command register

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: 81b23ef82cd1be29ca3d69ab7e98b5b5e55926ce
      
https://github.com/qemu/qemu/commit/81b23ef82cd1be29ca3d69ab7e98b5b5e55926ce
  Author: Jan Beulich <address@hidden>
  Date:   2015-04-09 (Thu, 09 Apr 2015)

  Changed paths:
    M hw/xen/xen_pt.c
    M hw/xen/xen_pt_config_init.c

  Log Message:
  -----------
  xen: limit guest control of PCI command register

Otherwise the guest can abuse that control to cause e.g. PCIe
Unsupported Request responses (by disabling memory and/or I/O decoding
and subsequently causing [CPU side] accesses to the respective address
ranges), which (depending on system configuration) may be fatal to the
host.

This is CVE-2015-2756 / XSA-126.

Signed-off-by: Jan Beulich <address@hidden>
Reviewed-by: Stefano Stabellini <address@hidden>
Acked-by: Ian Campbell <address@hidden>
Message-id: address@hidden
Signed-off-by: Peter Maydell <address@hidden>