Xen ≫ Xen

x86 PV guests can free memory pages while still keeping a stale TLB entry pointing to them. A TLB flush is only issued by Xen (if needed) when the page is re-used. Since it's possible for the page to be scrubbed ahead of the TLB flush, there's a wi...

A guest with a PCI device assigned that has at least a BAR on the IO port space can trigger a BUG() in Xen.

When guests are terminated, various pieces of cleanup need carrying out. The cleaning up of PCI devices which were assigned to guests, and the associated removal of tracking structures for IRQs used by the devices occurs relatively early in the proce...

A guest started with Populated on Demand enabled (PoD) can attempt to reclaim pages which aren't regular guest RAM. This can cause corruption of memory management state in Xen.

Parts of the DM_OP handling code assumes the caller has provided the required number of buffers for the given operation without any checking being done. As a result, certain operations might access stack rubble as structures are possibly uninitializ...

The EVTCHNOP_expand_array hypercall checks for whether FIFO event channels are enabled, but without holding the correct lock. It can race with EVTCHNOP_reset, resulting in dereferencing a NULL pointer.

The logic to handle periodic Viridian STIMERs performs a division with an unchecked user-controlled divisor value, that can be set to zero to cause a #DE fault.

Accesses to the CMOS memory contents are done using an indirect IO port pair. Therefore Xen needs to cache the guest chosen index, and one of the usages of the index didn't take the necessary locking to avoid concurrent changes. As a result, a gues...

Accessing the vNUMA configuration data of a guest is still possible when domain destruction has already started. The cleaning up of that configuration information is not synchronized with its retrieval by a device model controlling the guest.

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] With the introduction of Grant Table v2 came the requirement to be able to switch between versions. Switching from v1 t...