{"id":24644,"date":"2026-09-16T20:32:35","date_gmt":"2026-09-16T12:32:35","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-89957"},"modified":"2026-09-16T20:32:35","modified_gmt":"2026-09-16T12:32:35","slug":"cve-2026-89957","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-89957","title":{"rendered":"CVE-2026-89957 &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\ns390\/vfio-ap: Fix hot"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>s390\/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain removed<\/p>\n<p>The vfio_ap_mdev_hot_unplug_cfg() function uses the return value of<br \/>\nbitmap_andnot() to determine whether the guest APCB needs to be updated.<br \/>\nHowever, bitmap_andnot() returns false when the resulting destination<br \/>\nbitmap is empty. This means that if the only adapter, domain or control<br \/>\ndomain assigned to an mdev is removed from the host&#8217;s AP configuration,<br \/>\nthe bit is correctly cleared from the shadow APCB, but bitmap_andnot()<br \/>\nreturns false because the result is an empty bitmap. Consequently,<br \/>\ndo_hotplug remains 0 and vfio_ap_mdev_update_guest_apcb() is never called,<br \/>\nleaving the KVM guest with stale hardware access to the unplugged AP<br \/>\ndevices.<\/p>\n<p>Fix this by replacing the bitmap_andnot() return value check with<br \/>\nbitmap_intersects() to determine whether the shadow APCB actually<br \/>\noverlaps with the removal mask. If there is an intersection, call<br \/>\nbitmap_andnot() solely for its side effect of clearing the bits, then<br \/>\nunconditionally set do_hotplug to trigger the guest APCB update.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>s390\/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain removed<\/p>\n<p>The vfio_ap_mdev_hot_unplug_cfg() function uses the re<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-24644","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/24644","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=24644"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=24644"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=24644"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}