CVE-2022-26362

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

http://www.openwall.com/lists/oss-security/2022/06/09/3

https://xenbits.xenproject.org/xsa/advisory-401.txt

http://xenbits.xen.org/xsa/advisory-401.html

https://lists.fedoraproject.org/archives/list/[email protected]/message/OH65U6FTTB5MLH5A6Q3TW7KVCGOG4MYI/

http://packetstormsecurity.com/files/167718/Xen-TLB-Flush-Bypass.html

https://www.debian.org/security/2022/dsa-5184

https://lists.fedoraproject.org/archives/list/[email protected]/message/RKRXZ4LHGCGMOG24ZCEJNY6R2BTS4S2Q/

https://security.gentoo.org/glsa/202208-23

Details

Risk Information

CVSS v2

CVSS v3