FKIE_CVE-2026-98254

Vulnerability from fkie_nvd - Published: 2026-10-06 09:18 - Updated: 2026-10-07 07:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: swiotlb: use the adjusted address for the highmem page lookup swiotlb_bounce() reads the page frame number from the slot's recorded orig_addr, then advances orig_addr by tlb_offset to reach the address the caller asked about. The highmem branch mixes the two: the offset within the page comes from the adjusted address, the page from the value before it. Once the adjustment crosses a page boundary the pair no longer describes one location, and the whole copy lands one page below the intended one for a positive tlb_offset, one above for a negative one. DMA_FROM_DEVICE writes the device data over the wrong page and leaves the intended one stale, DMA_TO_DEVICE feeds the device from a page the mapping may not cover. Partial syncs through dma_sync_single_range_for_*() are what make tlb_offset non-zero. The branch test is picked the same way, so a slot recorded in lowmem can be adjusted into highmem and the lowmem path then hands a highmem address to phys_to_virt(). Take both from orig_addr once it is final and keep pfn in the branch that uses it. PhysHighMem() asks the question straight from the address, as dma-debug already does.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0219b72f5c209732b2f03a8cc0d7240b5e428a99
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6e53b4d6afbde626255805d438cabb1cac482445
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/aa4709813b29db89f2307f968db5d24925dcdeb1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b7d7914a9ae3097e63d113007e4fb44d33d515b1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/dma/swiotlb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6e53b4d6afbde626255805d438cabb1cac482445",
              "status": "affected",
              "version": "5f89468e2f060031cd89fd4287298e0eaf246bf6",
              "versionType": "git"
            },
            {
              "lessThan": "aa4709813b29db89f2307f968db5d24925dcdeb1",
              "status": "affected",
              "version": "5f89468e2f060031cd89fd4287298e0eaf246bf6",
              "versionType": "git"
            },
            {
              "lessThan": "0219b72f5c209732b2f03a8cc0d7240b5e428a99",
              "status": "affected",
              "version": "5f89468e2f060031cd89fd4287298e0eaf246bf6",
              "versionType": "git"
            },
            {
              "lessThan": "b7d7914a9ae3097e63d113007e4fb44d33d515b1",
              "status": "affected",
              "version": "5f89468e2f060031cd89fd4287298e0eaf246bf6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e6108147dd91b94d1979b110f265710c254c99d5",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e77b796eb9b7ca3c1c0d574d0c155f55b59ca8d5",
              "versionType": "git"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
              "version": "5.10.47",
              "versionType": "semver"
            },
            {
              "lessThan": "5.13",
              "status": "affected",
              "version": "5.12.14",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/dma/swiotlb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nswiotlb: use the adjusted address for the highmem page lookup\n\nswiotlb_bounce() reads the page frame number from the slot\u0027s recorded\norig_addr, then advances orig_addr by tlb_offset to reach the address\nthe caller asked about. The highmem branch mixes the two: the offset\nwithin the page comes from the adjusted address, the page from the value\nbefore it.\n\nOnce the adjustment crosses a page boundary the pair no longer describes\none location, and the whole copy lands one page below the intended one\nfor a positive tlb_offset, one above for a negative one. DMA_FROM_DEVICE\nwrites the device data over the wrong page and leaves the intended one\nstale, DMA_TO_DEVICE feeds the device from a page the mapping may not\ncover. Partial syncs through dma_sync_single_range_for_*() are what make\ntlb_offset non-zero.\n\nThe branch test is picked the same way, so a slot recorded in lowmem can\nbe adjusted into highmem and the lowmem path then hands a highmem\naddress to phys_to_virt().\n\nTake both from orig_addr once it is final and keep pfn in the branch\nthat uses it. PhysHighMem() asks the question straight from the address,\nas dma-debug already does."
    }
  ],
  "id": "CVE-2026-98254",
  "lastModified": "2026-10-07T07:17:06.683",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-06T09:18:14.057",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0219b72f5c209732b2f03a8cc0d7240b5e428a99"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6e53b4d6afbde626255805d438cabb1cac482445"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/aa4709813b29db89f2307f968db5d24925dcdeb1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b7d7914a9ae3097e63d113007e4fb44d33d515b1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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