ISSUE DESCRIPTION ================= The internal function querying a domain's p2m table grabs the p2m lock by default, so that the answer to the query remains true until the caller can act on that information; it is up to the caller then to release the lock. Unfortunately, certain failure paths don't release the lock. IMPACT ====== A malicious or buggy guest may cause a deadlock, resulting in a DoS (Denial of Service) affecting the entire host. VULNERABLE SYSTEMS ================== Xen 4.11 and onward are vulnerable. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only systems running untrusted HVM or PVH guests are vulnerable. Systems running only PV guests are not vulnerable. MITIGATION ========== Running only PV guests will avoid this vulnerability. References: https://xenbits.xen.org/xsa/advisory-277.html
Acknowledgments: Name: the Xen project Upstream: Paul Durrant (Citrix)
Created xen tracking bugs for this issue: Affects: fedora-all [bug 1652251]