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 writable mappings using super page mappings. Such writable 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.

[source]

References

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