NULL Pointer Dereference Affecting xen package, versions <4.9.0-r4
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-ALPINE316-XEN-2845286
- published21 Jul 2020
- disclosed12 Sept 2017
Introduced: 12 Sep 2017
CVE-2017-14318 (opens in a new tab)How to fix?
Upgrade Alpine:3.16 xen to version 4.9.0-r4 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream xen package and not the xen package as distributed by Alpine.
See How to fix? for Alpine:3.16 relevant fixed versions and status.
An issue was discovered in Xen 4.5.x through 4.9.x. The function __gnttab_cache_flush handles GNTTABOP_cache_flush grant table operations. It checks to see if the calling domain is the owner of the page that is to be operated on. If it is not, the owner's grant table is checked to see if a grant mapping to the calling domain exists for the page in question. However, the function does not check to see if the owning domain actually has a grant table or not. Some special domains, such as DOMID_XEN, DOMID_IO and DOMID_COW are created without grant tables. Hence, if __gnttab_cache_flush operates on a page owned by these special domains, it will attempt to dereference a NULL pointer in the domain struct.