CVE-2026-89957
CVE CVE-2026-89957EUVD EUVD-2026-80557Published 2026-09-16T10:32:40.000ZLast changed 2026-09-16T14:40:37.000ZCVSS 8.8
What the advisory describes
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 vfio_ap_mdev_hot_unplug_cfg() function uses the return value of bitmap_andnot() to determine whether the guest APCB needs to be updated. However, bitmap_andnot() 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 bitmap_andnot() returns false because the result is an empty bitmap. Consequently, do_hotplug remains 0 and vfio_ap_mdev_update_guest_apcb() is never called, leaving the KVM guest with stale hardware access to the unplugged AP devices. Fix this by replacing the bitmap_andnot() return value check with bitmap_intersects() to determine whether the shadow APCB actually overlaps with the removal mask. If there is an intersection, call bitmap_andnot() solely for its side effect of clearing the bits, then unconditionally set do_hotplug to trigger the guest APCB update.
Source: EUVD (ENISA), in the words of the advisory.
Products the advisory names
These come from the advisory itself, not from any check we performed.
- Linux — Linux patch: 6.18.51; patch: 0; eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <04b35dd88c108b2d2ceaaa396aba1cb4049d5831; eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <753aa3bb1273bc0d36adb013d5915cc8ff6b72a9; patch: 6.6.157; patch: 7.2.5; eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <c45753c32d452d10d8efaeb52587e9e6e8126e33; eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <917f509bfb88048094dbb85c4e9dbc4d6fe4a886; patch: 6.1.188; patch: 7.3-rc1; eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <3a9b049bbdc40165d7f3e20b818eec95e5694d96; patch: 6.12.110; eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <f58e824de8577fe411f6199d659731a0f86a7275; 6.0
The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.
Carried in the product catalogue
An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.
- Linux — Linux
Does this concern one of your customers?
This page cannot answer that — it does not know your estate. Whoever has recorded their environments gets the answer the morning after publication, together with a paragraph they can forward to the customer unedited.
Try it for 28 daysPatchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.