iommu/amd: Fix IRQ unsafe locking in gdom allocation

{
  "id": "ae8fbe2293ae72599e9a2d4c99365315e473030053abc210d3007fc2e39d5e70",
  "url": "https://osv.dev/vulnerability/CVE-2026-68347",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "iommu/amd: Fix IRQ unsafe locking in gdom allocation",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Fix IRQ unsafe locking in gdom allocation Lockdep complains: [ 259.410489] ===================================================== [ 259.417287] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected [ 259.424667] 7.0.0-g51db1d8d2113 #54 Not tainted [ 259.429718] ----------------------------------------------------- [ 259.436516] qemu-system-x86/10143 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 259.444670] ff3b2b1c60305170 (&xa->xa_lock#25){+.+.}-{3:3}, at: __domain_flush_pages+0x17c/0x4b0 [ 259.454485] and this task is already holding: [ 259.460991] ff3b2b1c98504cc0 (&domain->lock){-.-.}-{3:3}, at: amd_iommu_iotlb_sync+0x25/0x60 [ 259.470408] which would create a new lock dependency: [ 259.476041] (&domain->lock){-.-.}-{3:3} -> (&xa->xa_lock#25){+.+.}-{3:3} [ 259.483615] but this new dependency connects a HARDIRQ-irq-safe lock: [ 259.492447] (&domain->lock){-.-.}-{3:3} [ 259.492449] ... which became HARDIRQ-irq-safe at: [ 259.503705] lock_acquire+0xb6/0x2e0 [ 259.507790] _raw_spin_lock_irqsave+0x3e/0x60 [ 259.512748] amd_iommu_flush_iotlb_all+0x20/0x50 [ 259.517996] iommu_dma_free_iova.isra.0+0x1b8/0x1e0 [ 259.523534] __iommu_dma_unmap+0xc2/0x140 [ 259.528100] iommu_dma_unmap_phys+0x55/0xc0 [ 259.532863] dma_unmap_phys+0x274/0x2e0 [ 259.537238] dma_unmap_page_attrs+0x17/0x30 [ 259.542000] nvme_unmap_data+0x13e/0x280 [ 259.546473] nvme_pci_complete_batch+0x45/0x70 [ 259.551524] nvme_irq+0x83",
    "evidence": "osv:CVE-2026-68347",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.1.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-68347",
      "aliases": [
        "CVE-2026-68347"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "757d2b1fdf5b7d6eead5963a49b5780617987ab8"
                },
                {
                  "fixed": "e0c78cdf35af3ada05f9309f4641e9f83c945dbd"
                },
                {
                  "fixed": "0db3a430d9681fdb29890bef6934cd89cd1745d0"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68347.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.0.0"
                },
                {
                  "fixed": "7.1.6"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68347.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.354555860Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0db3a430d9681fdb29890bef6934cd89cd1745d0",
        "https://git.kernel.org/stable/c/e0c78cdf35af3ada05f9309f4641e9f83c945dbd",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68347.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-68347",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68347.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-68347",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 508156,
  "published_at": "2026-08-10T12:03:24.02+00:00"
}