{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-98473", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-98473", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-10-18T15:15:35.479Z", "updatedAt": "2026-10-19T09:20:11.069Z", "importedAt": "2026-10-24T01:58:41.756Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "s390/vfio-ap: fix KVM GISC and page leak when queue removed from host config", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio-ap: fix KVM GISC and page leak when queue removed from host config\n\nThree related problems exist in the handling of KVM interrupt and page\nresources when a queue is removed from the host's AP configuration\nwhile assigned to a mediated device (mdev).\n\nProblem 1:\n~~~~~~~~~\nAP_RESPONSE_Q_NOT_AVAIL not handled in vfio_ap_mdev_reset_queue()\n\nWhen the AP bus removes a queue device whose adapter or domain has\nbeen removed from the host's AP configuration,\nvfio_ap_mdev_remove_queue() is called. If the queue is still in the\nhost's AP configuration at that point, it calls\nvfio_ap_mdev_reset_queue(), which issues a PQAP(ZAPQ). Since the\nadapter is already gone from the host configuration, ap_zapq() returns\nAP_RESPONSE_Q_NOT_AVAIL (0x01). This response code is not handled in\nvfio_ap_mdev_reset_queue()'s switch statement and falls through to\nthe default case, which issues a WARN but does not call\nvfio_ap_free_aqic_resources(). As a result, if IRQ handling was\nenabled for the queue by the guest, the KVM GISC registration and\nthe pinned guest page holding the notification indicator byte (NIB)\nare both leaked.\n\nThis is fixed by adding AP_RESPONSE_Q_NOT_AVAIL to the same case as\nAP_RESPONSE_DECONFIGURED and AP_RESPONSE_CHECKSTOPPED in\nvfio_ap_mdev_reset_queue(). Like those response codes, Q_NOT_AVAIL\nindicates the queue is not operational and no further reset attempts\nare possible; the correct action is to free the IRQ resources\nimmediately.\n\nProblem 2:\n~~~~~~~~~\n AP_RESPONSE_Q_NOT_AVAIL not handled in apq_status_check()\n\nIn vfio_ap_mdev_reset_queue(), there are four cases that indicate a queue\nreset has not yet completed, in which case apq_reset_check() is queued to\na work queue to verify completion of the reset operation. This function\nuses the PQAP(TAPQ) function to get the queue's status and calls\napq_status_check() to verify whether the reset has completed, failed or\nneeds to be executed again. As described in Problem #1 above,\napq_reset_check() does not specifically check for AP_RESPONSE_Q_NOT_AVAIL,\nthereby potentially leaking KVM GISC registration and the pinned guest page\nholding the NIB.\n\nThis is fixed by adding a case statement for AP_RESPONSE_Q_NOT_AVAIL to\napq_status_check() and returning -ENODEV for that case. The caller,\napq_reset_check() will then check for this return code and call\nvfio_ap_free_aqic_resources() to prevent the leak.\n\nProblem 3:\n~~~~~~~~~\nvfio_ap_free_aqic_resources() leaks saved_isc when kvm is NULL\n\nvfio_ap_free_aqic_resources() guards the call to\nkvm_s390_gisc_unregister() with:\n\n if (q->saved_isc != VFIO_AP_ISC_INVALID &&\n !WARN_ON(!(q->matrix_mdev && q->matrix_mdev->kvm)))\n\nIf matrix_mdev->kvm is NULL -- which can happen when\nvfio_ap_mdev_unset_kvm() has already run and cleared kvm before a\nsubsequent cleanup path reaches this function -- the WARN_ON fires\nand the entire block is skipped. This leaves q->saved_isc set to a\nnon-invalid value, creating a potential double-free on any subsequent\ncall to this function.\n\nWhen kvm is NULL the KVM guest is already torn down, so\nkvm_s390_gisc_unregister() need not and cannot be called; however,\nq->saved_isc must always be cleared. Fix this by separating the\nkvm_s390_gisc_unregister() call from the q->saved_isc reset. The\nWARN_ON now guards only the genuinely impossible case of matrix_mdev\nbeing NULL. A NULL kvm is handled gracefully by skipping only the\nunregister call, and q->saved_isc = VFIO_AP_ISC_INVALID is set\nunconditionally whenever saved_isc was not already invalid.\n\nAdditionally, add an else clause to the host-config check in\nvfio_ap_mdev_remove_queue() to call vfio_ap_free_aqic_resources()\ndirectly when the queue is not in the host's AP configuration. This\nserves as a backstop: when the AP bus fires the driver .remove\ncallback after an adapter is removed from the host config, the queue\nis by definition no longer addressable, so vfio_ap_mdev_reset_queue\n---truncated---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "b9bd10c43456d16abd97b717446f51afb3b88411", "status": "affected", "versionType": "git", "lessThan": "da69d3ac53490724eba0ade9deb4e539a6ae9034" }, { "version": "b9bd10c43456d16abd97b717446f51afb3b88411", "status": "affected", "versionType": "git", "lessThan": "cf441a0db681dfad5e89b015d6be11365159d7a9" }, { "version": "b9bd10c43456d16abd97b717446f51afb3b88411", "status": "affected", "versionType": "git", "lessThan": "3c3433657c82f200dae36c29e2b80681c81b85be" }, { "version": "b9bd10c43456d16abd97b717446f51afb3b88411", "status": "affected", "versionType": "git", "lessThan": "65e05ec252a9b79e75930d3c4dd42d8877db04c5" }, { "version": "582014b08cb83383cdd61f052cd81e8aa5023696", "status": "affected", "versionType": "git" }, { "version": "7abe1494896c052d5dcf4ba910656777aff72fbb", "status": "affected", "versionType": "git" }, { "version": "6.6.15", "status": "affected", "versionType": "semver", "lessThan": "6.7" }, { "version": "6.7.3", "status": "affected", "versionType": "semver", "lessThan": "6.8" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "6.8", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "6.8" }, { "version": "6.12.112", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.55", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.2.9", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.2.*" }, { "version": "7.3", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }