An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.
Weakness
The product does not handle or incorrectly handles an exceptional condition.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Xen | Xen | * | 4.13.0 (including) |
| Xen | Xen | 4.13.0-rc1 (including) | 4.13.0-rc1 (including) |
| Xen | Xen | 4.13.0-rc2 (including) | 4.13.0-rc2 (including) |
| Xen | Ubuntu | bionic | * |
| Xen | Ubuntu | eoan | * |
| Xen | Ubuntu | esm-apps/focal | * |
| Xen | Ubuntu | focal | * |
| Xen | Ubuntu | groovy | * |
| Xen | Ubuntu | hirsute | * |
| Xen | Ubuntu | impish | * |
| Xen | Ubuntu | trusty | * |
| Xen | Ubuntu | xenial | * |
References
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html
- http://www.openwall.com/lists/oss-security/2020/04/14/3
- http://xenbits.xen.org/xsa/advisory-316.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YMAW7D2MP6RE4BFI5BZWOBBWGY3VSOFN/
- https://security.gentoo.org/glsa/202005-08
- https://www.debian.org/security/2020/dsa-4723
- https://xenbits.xen.org/xsa/advisory-316.html
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html
- http://www.openwall.com/lists/oss-security/2020/04/14/3
- http://xenbits.xen.org/xsa/advisory-316.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YMAW7D2MP6RE4BFI5BZWOBBWGY3VSOFN/
- https://security.gentoo.org/glsa/202005-08
- https://www.debian.org/security/2020/dsa-4723
- https://xenbits.xen.org/xsa/advisory-316.html