{"cve":"CVE-2024-56669","nvd":{"published":"2024-12-27T15:15:26.797","modified":"2026-08-04T11:22:20.317","status":"Modified","description":"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  <TASK>\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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-401","CWE-416","CWE-476"],"references":["https://git.kernel.org/stable/c/1f2557e08a617a4b5e92a48a1a9a6f86621def18","https://git.kernel.org/stable/c/9a0a72d3ed919ebe6491f527630998be053151d8"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:57:56.913276502+00:00"},"epss":{"cve":"CVE-2024-56669","score":0.00212,"percentile":0.11496,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}