Description
x86 pv: Race condition in typeref acquisition Xen maintains a type reference count for pages, in addition to a regular reference count. This scheme is used to maintain invariants required for Xen's safety, e.g. PV guests may not have direct writeable access to pagetables; updates need auditing by Xen. Unfortunately, the logic for acquiring a type reference has a race condition, whereby a safely TLB flush is issued too early and creates a window where the guest can re-establish the read/write mapping before writeability is prohibited.
References (8)
Core 8
Core References
Vendor Advisory x_refsource_misc
https://xenbits.xenproject.org/xsa/advisory-401.txt
Patch, Vendor Advisory x_refsource_confirm
http://xenbits.xen.org/xsa/advisory-401.html
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
http://www.openwall.com/lists/oss-security/2022/06/09/3
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OH65U6FTTB5MLH5A6Q3TW7KVCGOG4MYI/
Third Party Advisory, VDB Entry x_refsource_misc
http://packetstormsecurity.com/files/167718/Xen-TLB-Flush-Bypass.html
Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2022/dsa-5184
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RKRXZ4LHGCGMOG24ZCEJNY6R2BTS4S2Q/
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202208-23
Scores
CVSS v3
6.4
EPSS
0.0005
EPSS Percentile
14.8%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-362
Status
published
Products (4)
debian/debian_linux
11.0
fedoraproject/fedora
35
fedoraproject/fedora
36
xen/xen
Published
Jun 09, 2022
Tracked Since
Feb 18, 2026