{"id":"CVE-2026-64475","state":"PUBLISHED","title":"vfio/pci: Release the VGA arbiter client on register_device() failure","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvfio/pci: Release the VGA arbiter client on register_device() failure\n\nThe re-order in the Fixes commit below displaced vfio_pci_vga_init() as\nthe last failure point of what is now vfio_pci_core_register_device()\nwithout introducing an unwind for the VGA arbiter registration.\n\nIn current kernels this is mostly benign because vfio_pci_set_decode()\nonly uses pci_dev state, but the original failure path could leave a\ncallback with a freed vdev cookie.  The stale registration also becomes\nunsafe again once the callback follows drvdata to the vfio device.\n\nAdd the required VGA unwind callout.","publishedAt":"2026-07-25T08:51:38.154Z","updatedAt":"2026-10-19T20:48:36.746Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"87856f9af04eaacf9848710625a4ffee1d020fa9","status":"affected","lessThan":"0f2a35a0c7ea7da347b814750eaa78adf3582381","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"8d65decde9afd2bd78bcfffdc0df73b82a0b5509","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"ef4c38d30b3744e89eb5048218904bb629ea8d47","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"9e0a3f642e607848669235f5069f35640abbfc88","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"42d758a09d2c46c42357ecde9a5492f015bde2e5","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"52adb2dff7ce3d8430e2bdc5988b618a430def85","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"278a5659c391fe5afe5f9ce1bad1fd24e90144f1","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"daedde7f024ecf88bc8e832ed40cf2c795f0796a","versionType":"git"},{"version":"d62dccb417cf972c978bf3c68a7d5e846bcf953e","status":"affected","versionType":"git"},{"version":"6694b8daffac5a8661071f085608afc78f7acd08","status":"affected","versionType":"git"},{"version":"5.10.37","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.11.21","status":"affected","lessThan":"5.12","versionType":"semver"},{"version":"5.12.4","status":"affected","lessThan":"5.13","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vfio/pci/vfio_pci_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vfio/pci/vfio_pci_core.c"]}],"references":["https://git.kernel.org/stable/c/0f2a35a0c7ea7da347b814750eaa78adf3582381","https://git.kernel.org/stable/c/8d65decde9afd2bd78bcfffdc0df73b82a0b5509","https://git.kernel.org/stable/c/ef4c38d30b3744e89eb5048218904bb629ea8d47","https://git.kernel.org/stable/c/9e0a3f642e607848669235f5069f35640abbfc88","https://git.kernel.org/stable/c/42d758a09d2c46c42357ecde9a5492f015bde2e5","https://git.kernel.org/stable/c/52adb2dff7ce3d8430e2bdc5988b618a430def85","https://git.kernel.org/stable/c/278a5659c391fe5afe5f9ce1bad1fd24e90144f1","https://git.kernel.org/stable/c/daedde7f024ecf88bc8e832ed40cf2c795f0796a"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64475.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64475","state":"PUBLISHED","datePublished":"2026-07-25T08:51:38.154Z","dateUpdated":"2026-10-19T20:48:36.746Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.791Z"},"containers":{"cna":{"title":"vfio/pci: Release the VGA arbiter client on register_device() failure","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvfio/pci: Release the VGA arbiter client on register_device() failure\n\nThe re-order in the Fixes commit below displaced vfio_pci_vga_init() as\nthe last failure point of what is now vfio_pci_core_register_device()\nwithout introducing an unwind for the VGA arbiter registration.\n\nIn current kernels this is mostly benign because vfio_pci_set_decode()\nonly uses pci_dev state, but the original failure path could leave a\ncallback with a freed vdev cookie.  The stale registration also becomes\nunsafe again once the callback follows drvdata to the vfio device.\n\nAdd the required VGA unwind callout."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"87856f9af04eaacf9848710625a4ffee1d020fa9","status":"affected","lessThan":"0f2a35a0c7ea7da347b814750eaa78adf3582381","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"8d65decde9afd2bd78bcfffdc0df73b82a0b5509","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"ef4c38d30b3744e89eb5048218904bb629ea8d47","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"9e0a3f642e607848669235f5069f35640abbfc88","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"42d758a09d2c46c42357ecde9a5492f015bde2e5","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"52adb2dff7ce3d8430e2bdc5988b618a430def85","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"278a5659c391fe5afe5f9ce1bad1fd24e90144f1","versionType":"git"},{"version":"4aeec3984ddc853f7c65903bde472ffdef738bae","status":"affected","lessThan":"daedde7f024ecf88bc8e832ed40cf2c795f0796a","versionType":"git"},{"version":"d62dccb417cf972c978bf3c68a7d5e846bcf953e","status":"affected","versionType":"git"},{"version":"6694b8daffac5a8661071f085608afc78f7acd08","status":"affected","versionType":"git"},{"version":"5.10.37","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.11.21","status":"affected","lessThan":"5.12","versionType":"semver"},{"version":"5.12.4","status":"affected","lessThan":"5.13","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vfio/pci/vfio_pci_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vfio/pci/vfio_pci_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0f2a35a0c7ea7da347b814750eaa78adf3582381"},{"url":"https://git.kernel.org/stable/c/8d65decde9afd2bd78bcfffdc0df73b82a0b5509"},{"url":"https://git.kernel.org/stable/c/ef4c38d30b3744e89eb5048218904bb629ea8d47"},{"url":"https://git.kernel.org/stable/c/9e0a3f642e607848669235f5069f35640abbfc88"},{"url":"https://git.kernel.org/stable/c/42d758a09d2c46c42357ecde9a5492f015bde2e5"},{"url":"https://git.kernel.org/stable/c/52adb2dff7ce3d8430e2bdc5988b618a430def85"},{"url":"https://git.kernel.org/stable/c/278a5659c391fe5afe5f9ce1bad1fd24e90144f1"},{"url":"https://git.kernel.org/stable/c/daedde7f024ecf88bc8e832ed40cf2c795f0796a"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The flaw is triggered through local `/dev/vga_arbiter` operations or accesses to a delegated VFIO VGA region; it is not directly network-reachable. The VGA-arbiter character-device interface is documented in the [kernel documentation](https://docs.kernel.org/gpu/vgaarbiter.html).\nAC:L - Once failed VFIO registration leaves the stale callback, a single first-use VGA lock or legacy VGA access invokes it. No race must be won, and the attacker controls the triggering access.\nPR:L - The failed bind may arise from boot or privileged orchestration, but the subsequent callback path has no capability check and can be triggered by a video-group user, delegated VFIO process, or VM tenant. Real host-root privileges are therefore not required in a reasonable deployment.\nUI:N - The attacker directly performs the VGA-arbiter or VFIO-region access, with no victim action required during exploitation. Prior system configuration or automated device binding is not user interaction.\nS:C - With VFIO GPU passthrough, QEMU translates guest legacy-VGA accesses into VFIO `pread()` and `pwrite()` operations, allowing a guest to activate the stale host callback and potentially compromise the host kernel across the VM boundary, as shown by [QEMU’s VFIO VGA implementation](https://gitlab.com/qemu-project/qemu/-/blob/e5b3a241 81ea0cebf1c5b20f44d016311b7048f0/hw/vfio/pci.c).\nC:H - Historical affected branches retain a callback cookie pointing to a freed `struct vfio_pci_device`; reclaiming that allocation can control its embedded `pdev` pointer and redirect kernel pointer dereferences. Under conservative UAF assessment, this can enable disclosure of arbitrary host memory.\nI:H - The dangling object and potentially stale module callback create exploitable memory-lifetime corruption that can be heap-shaped toward control-flow hijacking or arbitrary kernel modification. Successful exploitation can therefore execute code in the host kernel.\nA:H - An invalid reclaimed `pdev` or unloaded callback target can immediately produce a kernel page fault, oops, or panic. The trigger requires only one attacker-controlled VGA access after the stale registration exists."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:56:21.493Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.37","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11.21"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12.4"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64475","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:41:16.888282Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:48:36.746Z"}}]}}}