{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89795", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.767Z", "datePublished": "2026-09-16T10:30:26.529Z", "dateUpdated": "2026-10-19T08:52:50.099Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:52:50.099Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nPCI: Allow per function PCI slots to fix slot reset on s390\n\nOn s390 systems, which use a machine level hypervisor, PCI devices are\nalways accessed through a form of PCI pass-through which fundamentally\noperates on a per PCI function granularity. This is also reflected in the\ns390 PCI hotplug driver which creates hotplug slots for individual PCI\nfunctions. Its reset_slot() function, which is a wrapper for\nzpci_hot_reset_device(), thus also resets individual functions.\n\nCurrently, the pci_create_slot() assigns the same pci_slot object to\nmultifunction devices. This approach worked fine on s390 systems that only\nexposed virtual functions as individual PCI domains to the operating\nsystem. Since commit 44510d6fa0c0 (\"s390/pci: Handling multifunctions\")\ns390 supports exposing the topology of multifunction PCI devices by\ngrouping them in a shared PCI domain. This creates a problem when resetting\na function through the hotplug driver's slot_reset() interface.\n\nWhen attempting to reset a function through the hotplug driver, the shared\nslot assignment causes the wrong function to be reset instead of the\nintended one. It also leaks memory as we do create a pci_slot object for\nthe function, but don't correctly free it in pci_slot_release().\n\nAdd a flag for struct pci_slot to allow per function PCI slots for\nfunctions managed through a hypervisor, which exposes individual PCI\nfunctions while retaining the topology. Since we can use all 8 bits for\nslot 'number' (for ARI devices), change slot 'number' u16 to account for\nspecial values PCI_SLOT_PLACEHOLDER and PCI_SLOT_ALL_DEVICES." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is reached from local PCI reset paths (sysfs device reset, VFIO_DEVICE_RESET, and vfio_pci_core_enable()) that call pci_try_reset_function() -> pci_dev_reset_slot_function() -> s390 reset_slot()/zpci_hot_reset_device(); there is no network or adjacent-radio path.\nAC:L - On s390 multifunction domains pci_create_slot() matches PCI_SLOT(devfn) against a full 8-bit slot number, so siblings/VFs are assigned the wrong pci_slot and a reset deterministically invokes the other function's hotplug reset_slot() with no race or attacker-uncontrollable layout.\nPR:L - vfio_pci_core_enable() and VFIO_DEVICE_RESET call pci_try_reset_function() with no capable() check on the IOMMU path; IBM Z/LinuxONE SR-IOV VF passthrough routinely grants that VFIO fd to an unprivileged qemu/tenant user rather than init-namespace root.\nUI:N - The attacker opens the assigned VFIO device or issues VFIO_DEVICE_RESET themselves; prior admin binding of the zPCI function to vfio-pci is deployment configuration, not victim interaction.\nS:C - Function reset uses the wrongly shared pci_slot and issues zpci_hot_reset_device() on a sibling/PF outside the caller's VFIO device set, bypassing VFIO's slot-wide membership check and crossing zPCI per-function isolation into host or other-tenant devices.\nC:N - This is a wrong-function hardware reset plus a pci_slot lifetime leak; it does not perform an out-of-bounds read, use-after-free, or other disclosure of kernel or other users' memory.\nI:H - zpci_hot_reset_device() disable/re-enable of the unintended function wipes that function's hardware state behind its owner's driver, destroying in-flight I/O and device configuration on a host PF or another tenant's NIC/storage function.\nA:H - Surprise reset of an in-use PF or sibling denies that device and all VFs behind it, and can oops the bound host driver which continues MMIO against a freshly reset zPCI function, causing host kernel availability loss." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/pci/pci.c", "drivers/pci/slot.c", "include/linux/pci.h" ], "versions": [ { "version": "44510d6fa0c00aa90b80075caa6b313b25927475", "lessThan": "0d1a7d67f45645106578d65181e4e492dd20ed79", "status": "affected", "versionType": "git" }, { "version": "44510d6fa0c00aa90b80075caa6b313b25927475", "lessThan": "2050d900f9adbd6d6f38d30e182bcd9ad3108467", "status": "affected", "versionType": "git" }, { "version": "44510d6fa0c00aa90b80075caa6b313b25927475", "lessThan": "ecdcceed4d377b02d4ea036b65f83f962c38ede7", "status": "affected", "versionType": "git" }, { "version": "44510d6fa0c00aa90b80075caa6b313b25927475", "lessThan": "dcc5bec09e23bbc4f9de055a11fce9937244f2c8", "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/pci/pci.c", "drivers/pci/slot.c", "include/linux/pci.h" ], "versions": [ { "version": "5.8", "status": "affected" }, { "version": "0", "lessThan": "5.8", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "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": "5.8", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0d1a7d67f45645106578d65181e4e492dd20ed79" }, { "url": "https://git.kernel.org/stable/c/2050d900f9adbd6d6f38d30e182bcd9ad3108467" }, { "url": "https://git.kernel.org/stable/c/ecdcceed4d377b02d4ea036b65f83f962c38ede7" }, { "url": "https://git.kernel.org/stable/c/dcc5bec09e23bbc4f9de055a11fce9937244f2c8" } ], "title": "PCI: Allow per function PCI slots to fix slot reset on s390", "x_generator": { "engine": "bippy-1.2.0" } } } }