FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

xen-kernel -- Uncontrolled creation of large page mappings by PV guests

Affected packages
3.4 <= xen-kernel < 4.5.1_1

Details

VuXML ID 3d9f6260-881d-11e5-ab94-002590263bf5
Discovery 2015-10-29
Entry 2015-11-11

The Xen Project reports:

The code to validate level 2 page table entries is bypassed when certain conditions are satisfied. This means that a PV guest can create writeable mappings using super page mappings. Such writeable mappings can violate Xen intended invariants for pages which Xen is supposed to keep read-only. This is possible even if the "allowsuperpage" command line option is not used.

Malicious PV guest administrators can escalate privilege so as to control the whole system.

References

CVE Name CVE-2015-7835
URL http://xenbits.xen.org/xsa/advisory-148.html