{"id":"CVE-2026-89795","published":"2026-09-16T11:16:44.307","lastModified":"2026-09-16T15:18:09.640","description":"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.","cvssScore":8.4,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/2050d900f9adbd6d6f38d30e182bcd9ad3108467","tags":[]},{"url":"https://git.kernel.org/stable/c/dcc5bec09e23bbc4f9de055a11fce9937244f2c8","tags":[]},{"url":"https://git.kernel.org/stable/c/ecdcceed4d377b02d4ea036b65f83f962c38ede7","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The flaw allows incorrect slot reset on s390 systems, potentially leading to memory leaks and misbehavior of PCI functions.","exploitability":"Exploitation requires access to the system and knowledge of the PCI device layout. It is moderately hard to exploit.","blast_radius":"If exploited, it could lead to system instability or security issues due to incorrect function resets.","remediation":"Upgrade to the fixed version 5.10.144 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["pci","s390","memory-leak","system-stability"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-10-02T08:50:26.793Z"}}