{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "4602e5757bcceb231c3a13c36c373ad4a750eddb"
            },
            {
              "fixed": "05d239f2c95e66e27e7fb4e99ee07eb56e3e34b0"
            },
            {
              "fixed": "6f92a7a8b48a523f910ef25dd83808710724f59b"
            },
            {
              "fixed": "09d620555e59768776090073a2c59d2bc8506eb3"
            },
            {
              "fixed": "97c5550b763171dbef61e6239cab372b9f9cd4a2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.9.0"
            },
            {
              "fixed": "6.12.78"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.19"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43486.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: contpte: fix set_access_flags() no-op check for SMMU/ATS faults\n\ncontpte_ptep_set_access_flags() compared the gathered ptep_get() value\nagainst the requested entry to detect no-ops. ptep_get() ORs AF/dirty\nfrom all sub-PTEs in the CONT block, so a dirty sibling can make the\ntarget appear already-dirty. When the gathered value matches entry, the\nfunction returns 0 even though the target sub-PTE still has PTE_RDONLY\nset in hardware.\n\nFor a CPU with FEAT_HAFDBS this gathered view is fine, since hardware may\nset AF/dirty on any sub-PTE and CPU TLB behavior is effectively gathered\nacross the CONT range. But page-table walkers that evaluate each\ndescriptor individually (e.g. a CPU without DBM support, or an SMMU\nwithout HTTU, or with HA/HD disabled in CD.TCR) can keep faulting on the\nunchanged target sub-PTE, causing an infinite fault loop.\n\nGathering can therefore cause false no-ops when only a sibling has been\nupdated:\n - write faults: target still has PTE_RDONLY (needs PTE_RDONLY cleared)\n - read faults:  target still lacks PTE_AF\n\nFix by checking each sub-PTE against the requested AF/dirty/write state\n(the same bits consumed by __ptep_set_access_flags()), using raw\nper-PTE values rather than the gathered ptep_get() view, before\nreturning no-op. Keep using the raw target PTE for the write-bit unfold\ndecision.\n\nPer Arm ARM (DDI 0487) D8.7.1 (\"The Contiguous bit\"), any sub-PTE in a CONT\nrange may become the effective cached translation and software must\nmaintain consistent attributes across the range.",
  "id": "CVE-2026-43486",
  "modified": "2026-07-15T01:49:17.511973527Z",
  "published": "2026-05-13T15:08:32.085Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/05d239f2c95e66e27e7fb4e99ee07eb56e3e34b0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/09d620555e59768776090073a2c59d2bc8506eb3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6f92a7a8b48a523f910ef25dd83808710724f59b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/97c5550b763171dbef61e6239cab372b9f9cd4a2"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43486.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43486"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "arm64: contpte: fix set_access_flags() no-op check for SMMU/ATS faults"
}