{"id":"CVE-2023-53123","summary":"PCI: s390: Fix use-after-free of PCI resources with per-function hotplug","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nPCI: s390: Fix use-after-free of PCI resources with per-function hotplug\n\nOn s390 PCI functions may be hotplugged individually even when they\nbelong to a multi-function device. In particular on an SR-IOV device VFs\nmay be removed and later re-added.\n\nIn commit a50297cf8235 (\"s390/pci: separate zbus creation from\nscanning\") it was missed however that struct pci_bus and struct\nzpci_bus's resource list retained a reference to the PCI functions MMIO\nresources even though those resources are released and freed on\nhot-unplug. These stale resources may subsequently be claimed when the\nPCI function re-appears resulting in use-after-free.\n\nOne idea of fixing this use-after-free in s390 specific code that was\ninvestigated was to simply keep resources around from the moment a PCI\nfunction first appeared until the whole virtual PCI bus created for\na multi-function device disappears. The problem with this however is\nthat due to the requirement of artificial MMIO addreesses (address\ncookies) extra logic is then needed to keep the address cookies\ncompatible on re-plug. At the same time the MMIO resources semantically\nbelong to the PCI function so tying their lifecycle to the function\nseems more logical.\n\nInstead a simpler approach is to remove the resources of an individually\nhot-unplugged PCI function from the PCI bus's resource list while\nkeeping the resources of other PCI functions on the PCI bus untouched.\n\nThis is done by introducing pci_bus_remove_resource() to remove an\nindividual resource. Similarly the resource also needs to be removed\nfrom the struct zpci_bus's resource list. It turns out however, that\nthere is really no need to add the MMIO resources to the struct\nzpci_bus's resource list at all and instead we can simply use the\nzpci_bar_struct's resource pointer directly.","modified":"2026-04-03T13:14:36.016893Z","published":"2025-05-02T15:55:59.580Z","related":["SUSE-SU-2025:01918-1","SUSE-SU-2025:01966-1","SUSE-SU-2025:02173-1","SUSE-SU-2025:02262-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53123.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/437bb839e36cc9f35adc6d2a2bf113b7a0fc9985"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a2410d0c3d2d714ed968a135dfcbed6aa3ff7027"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ab909509850b27fd39b8ba99e44cda39dbc3858c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b99ebf4b62774e690e73a551cf5fbf6f219bdd96"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53123.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53123"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43"},{"fixed":"437bb839e36cc9f35adc6d2a2bf113b7a0fc9985"},{"fixed":"a2410d0c3d2d714ed968a135dfcbed6aa3ff7027"},{"fixed":"b99ebf4b62774e690e73a551cf5fbf6f219bdd96"},{"fixed":"ab909509850b27fd39b8ba99e44cda39dbc3858c"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53123.json"}}],"schema_version":"1.7.5"}