{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46036", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.093Z", "datePublished": "2026-05-27T12:56:46.381Z", "dateUpdated": "2026-08-05T12:29:15.525Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:29:15.525Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvfio/cdx: Serialize VFIO_DEVICE_SET_IRQS with a per-device mutex\n\nvfio_cdx_set_msi_trigger() reads vdev->config_msi and operates on the\nvdev->cdx_irqs array based on its value, but provides no serialization\nagainst concurrent VFIO_DEVICE_SET_IRQS ioctls. Two callers can race\nsuch that one observes config_msi as set while another clears it and\nfrees cdx_irqs via vfio_cdx_msi_disable(), resulting in a use-after-free\nof the cdx_irqs array.\n\nAdd a cdx_irqs_lock mutex to struct vfio_cdx_device and acquire it in\nvfio_cdx_set_msi_trigger(), which is the single chokepoint through\nwhich all updates to config_msi, cdx_irqs, and msi_count flow, covering\nboth the ioctl path and the close-device cleanup path. This keeps the\ntest of config_msi atomic with the subsequent enable, disable, or\ntrigger operations.\n\nDrop the pre-call !cdx_irqs test from vfio_cdx_irqs_cleanup() as part\nof this change: the optimization it provided is redundant with the\n!config_msi early-return inside vfio_cdx_msi_disable(), and leaving the\ntest in place would be an unsynchronized read of state the new lock is\nmeant to protect." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only via ioctl(VFIO_DEVICE_SET_IRQS) on a local /dev/vfio device file; there is no network or adjacent-network exposure.\nAC:L - This is an attacker-controlled race — the attacker issues concurrent enable/trigger and disable SET_IRQS ioctls from two threads on the same fd, controlling both sides, and the unserialized core dispatch lets them run in parallel and be hammered until won.\nPR:L - VFIO's threat model hands the device fd to unprivileged userspace (VM/passthrough processes), so an attacker only needs access to an already-bound vfio-cdx device fd, not init-namespace root; when uncertain, the higher-severity L is chosen.\nUI:N - Triggering the race requires only the attacker's own concurrent ioctls; no victim action is needed.\nS:U - The use-after-free corrupts the kernel's own cdx_irqs management array within the kernel security authority and does not cross an IOMMU/VM boundary.\nC:H - Use-after-free of a heap array whose freed contents are read back (including pointers) allows the attacker to reallocate the slab with controlled data and disclose kernel memory.\nI:H - The freed array's entries (a dereferenced/callable eventfd_ctx pointer and pointers passed to kfree/free_irq) enable heap-spray-based arbitrary write and control-flow hijacking.\nA:H - The use-after-free reliably causes kernel oops/panic when the freed cdx_irqs array is accessed." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/vfio/cdx/intr.c", "drivers/vfio/cdx/main.c", "drivers/vfio/cdx/private.h" ], "versions": [ { "version": "848e447e000c41894ff931dc7c004fd42c8840f8", "lessThan": "ddf96e23c366c566283fce8377928851fa7f5e81", "status": "affected", "versionType": "git" }, { "version": "848e447e000c41894ff931dc7c004fd42c8840f8", "lessThan": "7b436ade16cc81095d79b79f8efa3af0a4f5c5a2", "status": "affected", "versionType": "git" }, { "version": "848e447e000c41894ff931dc7c004fd42c8840f8", "lessThan": "7530f34ec0ca1438d45a75dcb43183a1cc92eced", "status": "affected", "versionType": "git" }, { "version": "848e447e000c41894ff931dc7c004fd42c8840f8", "lessThan": "670e8864b1a218d72f08db40d0103adf38fa1d9b", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/vfio/cdx/intr.c", "drivers/vfio/cdx/main.c", "drivers/vfio/cdx/private.h" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.86", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.27", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.4", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.12.86" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.18.27" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.0.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ddf96e23c366c566283fce8377928851fa7f5e81" }, { "url": "https://git.kernel.org/stable/c/7b436ade16cc81095d79b79f8efa3af0a4f5c5a2" }, { "url": "https://git.kernel.org/stable/c/7530f34ec0ca1438d45a75dcb43183a1cc92eced" }, { "url": "https://git.kernel.org/stable/c/670e8864b1a218d72f08db40d0103adf38fa1d9b" } ], "title": "vfio/cdx: Serialize VFIO_DEVICE_SET_IRQS with a per-device mutex", "x_generator": { "engine": "bippy-1.2.0" } } } }