guests may exceed their designated memory limit When a guest is permitted to have close to 16TiB of memory, it may be able to issue hypercalls to increase its memory allocation beyond the administrator established limit. This is a result of a calculation done with 32-bit precision, which may overflow. It would then only be the overflowed (and hence small) number which gets compared against the established upper bound.
| Software | From | Fixed in |
|---|---|---|
| xen / xen | 3.2 | 4.12 |
| fedoraproject / fedora | 34 | 34.x |
| fedoraproject / fedora | 35 | 35.x |
| debian / debian_linux | 11.0 | 11.0.x |