{"id":"CVE-2026-89795","summary":"PCI: Allow per function PCI slots to fix slot reset on s390","details":"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.","modified":"2026-09-17T03:47:09.403770511Z","published":"2026-09-16T10:30:26.529Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89795.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2050d900f9adbd6d6f38d30e182bcd9ad3108467"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dcc5bec09e23bbc4f9de055a11fce9937244f2c8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ecdcceed4d377b02d4ea036b65f83f962c38ede7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89795.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89795"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"44510d6fa0c00aa90b80075caa6b313b25927475"},{"fixed":"2050d900f9adbd6d6f38d30e182bcd9ad3108467"},{"fixed":"ecdcceed4d377b02d4ea036b65f83f962c38ede7"},{"fixed":"dcc5bec09e23bbc4f9de055a11fce9937244f2c8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89795.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.8.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89795.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H"}]}