{"id":"CVE-2023-53123","state":"PUBLISHED","title":"PCI: s390: Fix use-after-free of PCI resources with per-function hotplug","description":"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.","publishedAt":"2025-05-02T15:55:59.580Z","updatedAt":"2026-05-11T19:38:56.432Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"437bb839e36cc9f35adc6d2a2bf113b7a0fc9985","versionType":"git"},{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"a2410d0c3d2d714ed968a135dfcbed6aa3ff7027","versionType":"git"},{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"b99ebf4b62774e690e73a551cf5fbf6f219bdd96","versionType":"git"},{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"ab909509850b27fd39b8ba99e44cda39dbc3858c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/pci/pci.c","arch/s390/pci/pci_bus.c","arch/s390/pci/pci_bus.h","drivers/pci/bus.c","include/linux/pci.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.104","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.21","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.8","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/pci/pci.c","arch/s390/pci/pci_bus.c","arch/s390/pci/pci_bus.h","drivers/pci/bus.c","include/linux/pci.h"]}],"references":["https://git.kernel.org/stable/c/437bb839e36cc9f35adc6d2a2bf113b7a0fc9985","https://git.kernel.org/stable/c/a2410d0c3d2d714ed968a135dfcbed6aa3ff7027","https://git.kernel.org/stable/c/b99ebf4b62774e690e73a551cf5fbf6f219bdd96","https://git.kernel.org/stable/c/ab909509850b27fd39b8ba99e44cda39dbc3858c"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53123.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53123","state":"PUBLISHED","datePublished":"2025-05-02T15:55:59.580Z","dateUpdated":"2026-05-11T19:38:56.432Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-05-02T15:51:43.555Z"},"containers":{"cna":{"title":"PCI: s390: Fix use-after-free of PCI resources with per-function hotplug","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"437bb839e36cc9f35adc6d2a2bf113b7a0fc9985","versionType":"git"},{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"a2410d0c3d2d714ed968a135dfcbed6aa3ff7027","versionType":"git"},{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"b99ebf4b62774e690e73a551cf5fbf6f219bdd96","versionType":"git"},{"version":"a50297cf8235b062bcdeaa8b1dad58e69d3e1b43","status":"affected","lessThan":"ab909509850b27fd39b8ba99e44cda39dbc3858c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/pci/pci.c","arch/s390/pci/pci_bus.c","arch/s390/pci/pci_bus.h","drivers/pci/bus.c","include/linux/pci.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.104","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.21","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.8","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/pci/pci.c","arch/s390/pci/pci_bus.c","arch/s390/pci/pci_bus.h","drivers/pci/bus.c","include/linux/pci.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/437bb839e36cc9f35adc6d2a2bf113b7a0fc9985"},{"url":"https://git.kernel.org/stable/c/a2410d0c3d2d714ed968a135dfcbed6aa3ff7027"},{"url":"https://git.kernel.org/stable/c/b99ebf4b62774e690e73a551cf5fbf6f219bdd96"},{"url":"https://git.kernel.org/stable/c/ab909509850b27fd39b8ba99e44cda39dbc3858c"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T19:38:56.432Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.1.21"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.2.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}