CVE-2026-89960

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89960", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.778Z", "datePublished": "2026-09-16T10:32:42.618Z", "dateUpdated": "2026-10-30T12:33:36.599Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:33:36.599Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio-ap: fix stale pqap_hook pointer on error in vfio_ap_mdev_set_kvm()\n\nIn vfio_ap_mdev_set_kvm(), kvm->arch.crypto.pqap_hook is set to\n&matrix_mdev->pqap_hook before the update locks are acquired and the\nmdev list is checked for a conflicting assignment. If another mdev is\nalready attached to the same KVM instance, the function returns -EPERM\nwithout restoring the hook pointer, leaving kvm->arch.crypto.pqap_hook\npointing at the failing matrix_mdev instead of the mdev that legitimately\nowns the KVM.\n\nSince matrix_mdev->kvm is never set on this error path,\nvfio_ap_mdev_unset_kvm() will not clean up the hook when matrix_mdev\nis later closed. If matrix_mdev is subsequently freed, any PQAP\ninstruction executed by the guest will dereference the stale pointer\nthrough pqap_hook_rwsem, resulting in a use-after-free.\n\nSince kvm->arch.crypto.pqap_hook is only set in the vfio_ap_mdev_set_kvm()\nfunction and is cleared in the vfio_ap_mdev_unset_kvm() function, a check\nfor 'kvm->arch.crypto.pqap_hook != NULL' is all that is needed to determine\nwhether it belongs to another mdev. This will alleviate the need to iterate\nthe matrix_dev->mdev_list list to see if the kvm object is assigned to\nanother mdev.This was introduced in v3 to alleviate the need to take the\nmdevs_lock while iterating the list; however, this did not prevent a\npotential race condition.\n\nThe pqap_hook_rwsem(write) is now performed inside\nget_update_locks_for_kvm(), which is updated to acquire\npqap_hook_rwsem(write) between kvm->lock and mdevs_lock. This ordering\nis consistent with the PQAP intercept path, which acquires pqap_hook_rwsem\nin read mode while srcu is held under vcpu->mutex, establishing the\ndependency: kvm->lock -> vcpu->mutex -> srcu -> pqap_hook_rwsem(read).\n\nThe pqap_hook_rwsem is now released inside the\nrelease_update_locks_for_kvm(), which is updated to release\npqap_hook_rwsem(write) between mdevs_lock and kvm->lock.\n\nAdditionally, kvm_put_kvm() in vfio_ap_mdev_unset_kvm() is moved\nafter release_update_locks_for_kvm(). Previously it was called while\nkvm->lock was held; if it were ever the last reference, kvm_destroy_vm()\nwould run under kvm->lock, which would deadlock."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is reached by opening vfio-ap mdev fds and linking them to a KVM instance (KVM_DEV_VFIO_FILE_ADD/BIND_IOMMUFD) so vfio_ap_mdev_open_device() calls vfio_ap_mdev_set_kvm(), then by a guest PQAP(AQIC) intercept in handle_pqap(); that is a local VFIO/KVM path with no network or USB exposure.\nAC:L - An attacker who can open two vfio-ap mdevs against the same KVM deterministically hits the -EPERM conflict path that overwrites kvm->arch.crypto.pqap_hook without restoring it, then frees the failing mdev and issues PQAP from the still-running guest; the attacker controls every step, with no victim race or uncontrolled layout.\nPR:L - vfio_ap_mdev_set_kvm() and the PQAP intercept have no capable() gate; /dev/kvm and /dev/vfio nodes are routinely granted to an unprivileged qemu/kvm-group tenant with assigned vfio-ap mdevs, so host root is not required, and user namespaces cannot substitute for this path.\nUI:N - The attacker performs the conflicting VFIO attach, tears down the failing mdev, and executes PQAP in their own guest; prior administrator creation of vfio-ap mdevs is deployment configuration, not victim interaction during exploitation.\nS:C - A guest PQAP intercept on the host calls through kvm->arch.crypto.pqap_hook into a freed ap_matrix_mdev in the host vfio-ap driver, hijacking a host kernel function pointer and crossing the KVM/VFIO guest-to-host isolation boundary (VM escape).\nC:H - After the failing mdev is kvfree'd, handle_pqap() does pqap_hook = *vcpu->kvm->arch.crypto.pqap_hook, reading a function pointer from the freed ap_matrix_mdev; reclaiming that object yields an arbitrary kernel-read primitive, which kernel UAF guidance scores High.\nI:H - The intercept then invokes that recovered pointer as pqap_hook(vcpu); spraying the freed ap_matrix_mdev replaces the hook with an attacker-controlled address, enabling host kernel control-flow hijack and arbitrary write.\nA:H - The same stale-pointer dereference and call on the freed object causes a host kernel oops or panic when the guest issues PQAP, even if the function pointer is not fully hijacked."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/s390/crypto/vfio_ap_ops.c"], "versions": [{"version": "86956e70761b3292156d668e87126844334dd71b", "lessThan": "d6b7b166d5310fa3e4d5802c4177a0264d9140bd", "status": "affected", "versionType": "git"}, {"version": "86956e70761b3292156d668e87126844334dd71b", "lessThan": "eb6cc898501a004c0fa8aab951351d9c959b91cc", "status": "affected", "versionType": "git"}, {"version": "86956e70761b3292156d668e87126844334dd71b", "lessThan": "6a180adafc2a8a5fbe815985c71b2201e93ab5e1", "status": "affected", "versionType": "git"}, {"version": "86956e70761b3292156d668e87126844334dd71b", "lessThan": "fc069d00a0dbef40042fd681554d48dcd5a1d524", "status": "affected", "versionType": "git"}, {"version": "86956e70761b3292156d668e87126844334dd71b", "lessThan": "13bfc94eef389bd664ffc67b00184919902c938a", "status": "affected", "versionType": "git"}, {"version": "86956e70761b3292156d668e87126844334dd71b", "lessThan": "4400270ec0348d05dc0439d8f0130853ce7f9e20", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/s390/crypto/vfio_ap_ops.c"], "versions": [{"version": "5.15", "status": "affected"}, {"version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.110"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.51"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/d6b7b166d5310fa3e4d5802c4177a0264d9140bd"}, {"url": "https://git.kernel.org/stable/c/eb6cc898501a004c0fa8aab951351d9c959b91cc"}, {"url": "https://git.kernel.org/stable/c/6a180adafc2a8a5fbe815985c71b2201e93ab5e1"}, {"url": "https://git.kernel.org/stable/c/fc069d00a0dbef40042fd681554d48dcd5a1d524"}, {"url": "https://git.kernel.org/stable/c/13bfc94eef389bd664ffc67b00184919902c938a"}, {"url": "https://git.kernel.org/stable/c/4400270ec0348d05dc0439d8f0130853ce7f9e20"}], "title": "s390/vfio-ap: fix stale pqap_hook pointer on error in vfio_ap_mdev_set_kvm()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/s390/crypto/vfio_ap_ops.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "d6b7b166d5310fa3e4d5802c4177a0264d9140bd", "status": "affected", "version": "86956e70761b3292156d668e87126844334dd71b", "versionType": "git"}, {"lessThan": "eb6cc898501a004c0fa8aab951351d9c959b91cc", "status": "affected", "version": "86956e70761b3292156d668e87126844334dd71b", "versionType": "git"}, {"lessThan": "6a180adafc2a8a5fbe815985c71b2201e93ab5e1", "status": "affected", "version": "86956e70761b3292156d668e87126844334dd71b", "versionType": "git"}, {"lessThan": "fc069d00a0dbef40042fd681554d48dcd5a1d524", "status": "affected", "version": "86956e70761b3292156d668e87126844334dd71b", "versionType": "git"}, {"lessThan": "13bfc94eef389bd664ffc67b00184919902c938a", "status": "affected", "version": "86956e70761b3292156d668e87126844334dd71b", "versionType": "git"}, {"lessThan": "4400270ec0348d05dc0439d8f0130853ce7f9e20", "status": "affected", "version": "86956e70761b3292156d668e87126844334dd71b", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/s390/crypto/vfio_ap_ops.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"lessThan": "5.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.110", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.51", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio-ap: fix stale pqap_hook pointer on error in vfio_ap_mdev_set_kvm()\n\nIn vfio_ap_mdev_set_kvm(), kvm->arch.crypto.pqap_hook is set to\n&matrix_mdev->pqap_hook before the update locks are acquired and the\nmdev list is checked for a conflicting assignment. If another mdev is\nalready attached to the same KVM instance, the function returns -EPERM\nwithout restoring the hook pointer, leaving kvm->arch.crypto.pqap_hook\npointing at the failing matrix_mdev instead of the mdev that legitimately\nowns the KVM.\n\nSince matrix_mdev->kvm is never set on this error path,\nvfio_ap_mdev_unset_kvm() will not clean up the hook when matrix_mdev\nis later closed. If matrix_mdev is subsequently freed, any PQAP\ninstruction executed by the guest will dereference the stale pointer\nthrough pqap_hook_rwsem, resulting in a use-after-free.\n\nSince kvm->arch.crypto.pqap_hook is only set in the vfio_ap_mdev_set_kvm()\nfunction and is cleared in the vfio_ap_mdev_unset_kvm() function, a check\nfor 'kvm->arch.crypto.pqap_hook != NULL' is all that is needed to determine\nwhether it belongs to another mdev. This will alleviate the need to iterate\nthe matrix_dev->mdev_list list to see if the kvm object is assigned to\nanother mdev.This was introduced in v3 to alleviate the need to take the\nmdevs_lock while iterating the list; however, this did not prevent a\npotential race condition.\n\nThe pqap_hook_rwsem(write) is now performed inside\nget_update_locks_for_kvm(), which is updated to acquire\npqap_hook_rwsem(write) between kvm->lock and mdevs_lock. This ordering\nis consistent with the PQAP intercept path, which acquires pqap_hook_rwsem\nin read mode while srcu is held under vcpu->mutex, establishing the\ndependency: kvm->lock -> vcpu->mutex -> srcu -> pqap_hook_rwsem(read).\n\nThe pqap_hook_rwsem is now released inside the\nrelease_update_locks_for_kvm(), which is updated to release\npqap_hook_rwsem(write) between mdevs_lock and kvm->lock.\n\nAdditionally, kvm_put_kvm() in vfio_ap_mdev_unset_kvm() is moved\nafter release_update_locks_for_kvm(). Previously it was called while\nkvm->lock was held; if it were ever the last reference, kvm_destroy_vm()\nwould run under kvm->lock, which would deadlock."}], "id": "CVE-2026-89960", "lastModified": "2026-10-30T13:20:37.093", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-16T11:17:06.437", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/13bfc94eef389bd664ffc67b00184919902c938a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4400270ec0348d05dc0439d8f0130853ce7f9e20"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6a180adafc2a8a5fbe815985c71b2201e93ab5e1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d6b7b166d5310fa3e4d5802c4177a0264d9140bd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/eb6cc898501a004c0fa8aab951351d9c959b91cc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fc069d00a0dbef40042fd681554d48dcd5a1d524"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[86956e70761b3292156d668e87126844334dd71b,eb6cc898501a004c0fa8aab951351d9c959b91cc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[86956e70761b3292156d668e87126844334dd71b,6a180adafc2a8a5fbe815985c71b2201e93ab5e1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[86956e70761b3292156d668e87126844334dd71b,fc069d00a0dbef40042fd681554d48dcd5a1d524)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[86956e70761b3292156d668e87126844334dd71b,13bfc94eef389bd664ffc67b00184919902c938a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[86956e70761b3292156d668e87126844334dd71b,4400270ec0348d05dc0439d8f0130853ce7f9e20)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.157,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.110,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.51,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.5,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-17T16:00:07.770898+00:00", "updated": "2026-09-18T04:15:02.522610+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416", "CWE-362"]}