CVE-2022-26362
x86 pv: Race condition in typeref acquisition Xen maintains a type reference count for pages, in addition to a regular reference count.
Does this matter?
Lower severity and a low EPSS score (0.38%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.4 MEDIUMCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.38% probability · 31th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-362
- Affected
- xen/xen · fedoraproject/fedora · debian/debian linux
- Source
- security@xen.org
References
- http://packetstormsecurity.com/files/167718/Xen-TLB-Flush-Bypass.htmlThird Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2022/06/09/3Mailing List, Third Party Advisory
- http://xenbits.xen.org/xsa/advisory-401.htmlPatch, Vendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OH65U6FTTB5MLH5A6Q3TW7KVCGOG4MYI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RKRXZ4LHGCGMOG24ZCEJNY6R2BTS4S2Q/
- https://security.gentoo.org/glsa/202208-23Third Party Advisory
- https://www.debian.org/security/2022/dsa-5184Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-401.txtVendor Advisory
- http://packetstormsecurity.com/files/167718/Xen-TLB-Flush-Bypass.htmlThird Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2022/06/09/3Mailing List, Third Party Advisory
- http://xenbits.xen.org/xsa/advisory-401.htmlPatch, Vendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OH65U6FTTB5MLH5A6Q3TW7KVCGOG4MYI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RKRXZ4LHGCGMOG24ZCEJNY6R2BTS4S2Q/
- https://security.gentoo.org/glsa/202208-23Third Party Advisory
- https://www.debian.org/security/2022/dsa-5184Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-401.txtVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.