{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-56669", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-27T15:00:39.844Z", "datePublished": "2024-12-27T15:06:30.792Z", "dateUpdated": "2026-08-05T11:45:59.525Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:45:59.525Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Remove cache tags before disabling ATS\n\nThe current implementation removes cache tags after disabling ATS,\nleading to potential memory leaks and kernel crashes. Specifically,\nCACHE_TAG_DEVTLB type cache tags may still remain in the list even\nafter the domain is freed, causing a use-after-free condition.\n\nThis issue really shows up when multiple VFs from different PFs\npassed through to a single user-space process via vfio-pci. In such\ncases, the kernel may crash with kernel messages like:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000014\n PGD 19036a067 P4D 1940a3067 PUD 136c9b067 PMD 0\n Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI\n CPU: 74 UID: 0 PID: 3183 Comm: testCli Not tainted 6.11.9 #2\n RIP: 0010:cache_tag_flush_range+0x9b/0x250\n Call Trace:\n \n ? __die+0x1f/0x60\n ? page_fault_oops+0x163/0x590\n ? exc_page_fault+0x72/0x190\n ? asm_exc_page_fault+0x22/0x30\n ? cache_tag_flush_range+0x9b/0x250\n ? cache_tag_flush_range+0x5d/0x250\n intel_iommu_tlb_sync+0x29/0x40\n intel_iommu_unmap_pages+0xfe/0x160\n __iommu_unmap+0xd8/0x1a0\n vfio_unmap_unpin+0x182/0x340 [vfio_iommu_type1]\n vfio_remove_dma+0x2a/0xb0 [vfio_iommu_type1]\n vfio_iommu_type1_ioctl+0xafa/0x18e0 [vfio_iommu_type1]\n\nMove cache_tag_unassign_domain() before iommu_disable_pci_caps() to fix\nit." } ], "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 vulnerable path is reached through local VFIO/iommufd ioctls (device attach/detach followed by VFIO_IOMMU_UNMAP_DMA), as shown by the reported call trace through vfio_iommu_type1_ioctl. No network or physical access is involved.\nAC:L - This is a deterministic ordering bug, not a race: any attach/detach cycle of an ATS-capable device unconditionally orphans the CACHE_TAG_DEVTLB tag, and the attacker fully controls both the detach and the subsequent unmap that walks the stale tag.\nPR:L - An unprivileged local user granted access to a VFIO group/cdev — the explicitly supported \"safe userspace driver\" model used by DPDK, SPDK and QEMU/libvirt-assigned devices — can perform the attach/detach and unmap ioctls that trigger the stale tag, requiring only low privileges rather than real root.\nUI:N - The attacker's own sequence of ioctls on its VFIO container triggers the orphaned cache tag and the subsequent dereference; no action by any other user or administrator is needed.\nS:C - The defect is in the VT-d device-TLB invalidation tracking that enforces DMA isolation, and the corrupted tag causes ATS invalidation descriptors to be programmed into the IOMMU hardware from NULL/freed device_domain_info, affecting the DMA/IOMMU boundary that protects host memory from passthrough devices and their assigned guest owners.\nC:H - The stale tag causes a use-after-free read of the freed device_domain_info (and the freed struct device's dev_iommu), so heap-groomed contents of a reclaimed slab object are read out and used to construct hardware invalidation descriptors, giving an attacker-influenced read primitive against freed kernel memory.\nI:H - The use-after-free lets an attacker spray the reclaimed device_domain_info slot so that bus/devfn/pfsid/ats_qdep values under their control are written into queued-invalidation descriptors submitted to the IOMMU, and per standard treatment a UAF of this kind is leverageable for kernel memory corruption.\nA:H - The bug reproducibly panics the kernel — the reporter's NULL pointer dereference at address 0x14 in cache_tag_flush_range with multiple VFs passed through via vfio-pci — and the leaked cache tags additionally accumulate unbounded on every attach/detach cycle." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/iommu/intel/iommu.c" ], "versions": [ { "version": "3b1d9e2b2d6856eabf5faa12d20c97fef657999f", "lessThan": "9a0a72d3ed919ebe6491f527630998be053151d8", "status": "affected", "versionType": "git" }, { "version": "3b1d9e2b2d6856eabf5faa12d20c97fef657999f", "lessThan": "1f2557e08a617a4b5e92a48a1a9a6f86621def18", "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/iommu/intel/iommu.c" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.6", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13", "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": "6.12.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9a0a72d3ed919ebe6491f527630998be053151d8" }, { "url": "https://git.kernel.org/stable/c/1f2557e08a617a4b5e92a48a1a9a6f86621def18" } ], "title": "iommu/vt-d: Remove cache tags before disabling ATS", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-56669", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-11T15:41:33.499113Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-11T15:45:21.237Z" } } ] } }