Advisory: XSA-268 Release Date: 2018-08-14 17:00 Update Date: 2018-08-20 09:46 CVE: CVE-2018-15469 Title: Use of v2 grant tables may cause crash on ARM Issue Description: ARM systems never properly implemented grant table v2, either in the hypervisor or in Linux. Unprivileged guests can still request v2 grant tables, which are not properly set up, leading to subsequent grant-related hypercalls hitting BUG() checks. Impact: An unprivileged guest can trigger a BUG() check in the hypervisor, resulting in a denial-of-service. Vulnerable Systems: Only ARM systems are affected. All supported versions of Xen are vulnerable. Mitigation: None provided. Resolution: Applying the attached patches resolves the issue by preventing guest switching to grant v2. Discovery Credit: Discovered by 王磊 of Samsung.