Bug 2568116

Summary: CVE-2026-102703 xen: xen: privilege escalation via improper grant copy cache validation [fedora-all]
Product: [Fedora] Fedora Reporter: Ganesh <gnaik>
Component: xenAssignee: Michael Young <m.a.young>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: jforbes, m.a.young
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["1b1eb119-0d82-42c4-a12f-6b88c7878eb5"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Clone Of: Environment:
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Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2566831    

Description Ganesh 2026-11-06 13:58:56 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]

A common access pattern is a batch of Grant Copy operations acting on
adjacent address ranges in the same source or destination page.  For
performance reasons, Xen caches details internally to reuse already
validated data.  The conditions on when to re-validate the internal data
were not correct in some cases:

 - Frame numbers and grant references could wrongly be mixed up.  This
   is CVE-2026-102703.

 - Copying by frame number (rather than grant reference) is permitted
   only when operating on the caller's own memory.  The check to enforce
   this restriction was misplaced.  This is CVE-2026-102704.