Out-of-bounds accesses in Tapdisk

ISSUE DESCRIPTION Tapdisk is a userspace xen-blkback implementation used by the XAPI toolstack. Several bounds checks have been found to be incorrect. There is no upper bounds check for blkif-lastsect. Passing a value larger than 7 will result in a read or write beyond the mapped grant. This is...

PT-2026-88444

News: Xen published XSA-509 to 513 at 12:00 UTC. Worst is XSA-513 CVE-2026-79605/79606: a guest can run code in tapdisk as root in dom0. Also host DoS via PCI passthrough and oxenstored. Apply vendor Xen/XAPI patches now. https://t.co/CHBHEfTqbS...