UBUNTU-CVE-2026-89957: High severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: s390/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain removed The vfioapmdevhotunplugcfg() function uses the return value of bitmapandnot() to determine whether the guest APCB needs to be updated. However, bitmapandnot() returns false when the resulting destination bitmap is empty. This means that if the only adapter, domain or control domain assigned to an mdev is removed from the host's AP configuration, the bit is correctly cleared from the shadow APCB, but bitmapandnot() returns false because the result is an empty bitmap. Consequently, dohotplug remains 0 and vfioapmdevupdateguestapcb() is never called, leaving the KVM guest with stale hardware access to the unplugged AP devices. Fix this by replacing the bitmapandnot() return value check with bitmapintersects() to determine whether the shadow APCB actually overlaps with the removal mask. If there is an intersection, call bitmapandnot() solely for its side effect of clearing the bits, then unconditionally set dohotplug to trigger the guest APCB update.