Vulnerability-Lookup

FKIE_CVE-2026-80662

Vulnerability from fkie_nvd - Published: 2026-08-28 08:16 - Updated: 2026-08-29 07:16

Severity

7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size The CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58 bytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing 64 bytes at offset 0x18. CXL_HEADERLOG_SIZE was defined as SZ_512, eight times the actual on-device size. header_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the RAS capability iomap, overrunning the 88-byte mapping by 448 bytes. The cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE (512) bytes from its source. For the CPER caller the source is struct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a stack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes of kernel stack into the trace event ring buffer where userspace can read it via tracefs. Set CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it, bringing all iomap readers into agreement on 16 dwords. Userspace tools such as rasdaemon have grown a dependency on the buggy 512-byte (128 u32) header_log layout in the cxl_aer_uncorrectable_error trace event. Add CXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event __array and its memcpy to preserve that ABI. Both callers now pass a zero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only the first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware; the remaining 112 u32s are zero-padded, keeping the 512-byte trace ring buffer layout intact. [ dj: Replaced 64 with SZ_64 per RichardC ]

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6fc1919a6f2ed541484dd1f6cd93374044f8fd3d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c268f949e219f9e179558e836f457f6c5fbec416
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fc5eb0962a5e50d64e711817cc24d67df2d90528

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/cxl/core/ras.c",
            "drivers/cxl/core/trace.h",
            "drivers/cxl/cxl.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6fc1919a6f2ed541484dd1f6cd93374044f8fd3d",
              "status": "affected",
              "version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
              "versionType": "git"
            },
            {
              "lessThan": "fc5eb0962a5e50d64e711817cc24d67df2d90528",
              "status": "affected",
              "version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
              "versionType": "git"
            },
            {
              "lessThan": "c268f949e219f9e179558e836f457f6c5fbec416",
              "status": "affected",
              "version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/cxl/core/ras.c",
            "drivers/cxl/core/trace.h",
            "drivers/cxl/cxl.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "lessThan": "6.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\ncxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size\n\nThe CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58\nbytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing\n64 bytes at offset 0x18.  CXL_HEADERLOG_SIZE was defined as SZ_512,\neight times the actual on-device size.\n\nheader_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the\nRAS capability iomap, overrunning the 88-byte mapping by 448 bytes.\nThe cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE\n(512) bytes from its source.  For the CPER caller the source is\nstruct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a\nstack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes\nof kernel stack into the trace event ring buffer where userspace can\nread it via tracefs.\n\nSet CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it,\nbringing all iomap readers into agreement on 16 dwords.  Userspace tools\nsuch as rasdaemon have grown a dependency on the buggy 512-byte (128 u32)\nheader_log layout in the cxl_aer_uncorrectable_error trace event.  Add\nCXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event\n__array and its memcpy to preserve that ABI.  Both callers now pass a\nzero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only\nthe first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware;\nthe remaining 112 u32s are zero-padded, keeping the 512-byte trace ring\nbuffer layout intact.\n\n[ dj: Replaced 64 with SZ_64 per RichardC ]"
    }
  ],
  "id": "CVE-2026-80662",
  "lastModified": "2026-08-29T07:16:48.667",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-28T08:16:51.397",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6fc1919a6f2ed541484dd1f6cd93374044f8fd3d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c268f949e219f9e179558e836f457f6c5fbec416"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fc5eb0962a5e50d64e711817cc24d67df2d90528"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-80662 (GCVE-0-2026-80662)

Vulnerability from cvelistv5 – Published: 2026-08-28 06:49 – Updated: 2026-08-29 06:21

Title

cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size

Summary

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/6fc1919a6f2ed5414…
https://git.kernel.org/stable/c/fc5eb0962a5e50d64…
https://git.kernel.org/stable/c/c268f949e219f9e17…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 , < 6fc1919a6f2ed541484dd1f6cd93374044f8fd3d (git) Affected: 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 , < fc5eb0962a5e50d64e711817cc24d67df2d90528 (git) Affected: 2905cb5236cba63a5dc8a83752dcc31f3cc819f9 , < c268f949e219f9e179558e836f457f6c5fbec416 (git)
Linux	Linux	Affected: 6.2 Unaffected: 0 , < 6.2 (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/cxl/core/ras.c",
            "drivers/cxl/core/trace.h",
            "drivers/cxl/cxl.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6fc1919a6f2ed541484dd1f6cd93374044f8fd3d",
              "status": "affected",
              "version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
              "versionType": "git"
            },
            {
              "lessThan": "fc5eb0962a5e50d64e711817cc24d67df2d90528",
              "status": "affected",
              "version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
              "versionType": "git"
            },
            {
              "lessThan": "c268f949e219f9e179558e836f457f6c5fbec416",
              "status": "affected",
              "version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/cxl/core/ras.c",
            "drivers/cxl/core/trace.h",
            "drivers/cxl/cxl.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "lessThan": "6.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size\n\nThe CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58\nbytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing\n64 bytes at offset 0x18.  CXL_HEADERLOG_SIZE was defined as SZ_512,\neight times the actual on-device size.\n\nheader_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the\nRAS capability iomap, overrunning the 88-byte mapping by 448 bytes.\nThe cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE\n(512) bytes from its source.  For the CPER caller the source is\nstruct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a\nstack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes\nof kernel stack into the trace event ring buffer where userspace can\nread it via tracefs.\n\nSet CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it,\nbringing all iomap readers into agreement on 16 dwords.  Userspace tools\nsuch as rasdaemon have grown a dependency on the buggy 512-byte (128 u32)\nheader_log layout in the cxl_aer_uncorrectable_error trace event.  Add\nCXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event\n__array and its memcpy to preserve that ABI.  Both callers now pass a\nzero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only\nthe first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware;\nthe remaining 112 u32s are zero-padded, keeping the 512-byte trace ring\nbuffer layout intact.\n\n[ dj: Replaced 64 with SZ_64 per RichardC ]"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is only reached in kernel CXL RAS error handling (cxl_handle_ras via PCI AER cxl_error_detected, and CPER paths cxl_cper_post_prot_err/extlog_cxl_cper_handle_prot_err). Disclosure requires reading tracefs; there is no network, adjacent-radio, or direct physical-bus syscall entry to the vulnerable memcpy/readl sites.\nAC:L - With CAP_SYS_ADMIN, ACPI/CXL EINJ via debugfs einj_inject deterministically injects uncorrectable CXL protocol errors that traverse cxl_cper_handle_prot_err/cxl_handle_ras. Without root, a tracing-group member on CXL servers running rasdaemon can reliably capture the leak whenever organic uncorrectable RAS events occur.\nPR:L - Exploitation requires reading cxl_aer_uncorrectable_error data from tracefs (TRACE_MODE_READ 0440), routinely granted to tracing-group/rasdaemon service accounts on CXL/RAS deployments. Triggering on demand uses debugfs EINJ (root) or natural hardware errors; no init-namespace-only capability beyond tracefs DAC is needed for the stack leak.\nUI:N - Once CXL tracepoints are enabled (as rasdaemon does automatically), uncorrectable RAS/CPER processing copies the overlong header_log during kernel error handling. No victim mount, login, or interactive action is required beyond the attacker (or environment) having tracefs access when an error fires.\nS:U - The flaw leaks kernel stack/MMIO data into the trace ring buffer within the host kernel. Impact stays in the same OS security authority (local privilege/information gain) and does not cross guest/host, IOMMU, or container hardware trust boundaries.\nC:H - TP_fast_assign memcpy() copies 512 bytes from a 64-byte ras_cap.header_log on the stack, leaking 448 bytes of kernel stack into tracefs. header_log_copy() also readl()s 128 dwords from an 88-byte RAS iomap, an out-of-bounds read of adjacent MMIO/device memory.\nI:N - Both failure modes are out-of-bounds reads only (stack and MMIO). The trace event stores leaked bytes in the ring buffer but does not corrupt attacker-controlled memory or provide a direct arbitrary-write primitive.\nA:H - header_log_copy() performs 448 bytes of MMIO reads past the devm_ioremap() RAS window (0x58 bytes), which can provoke CPU/MMU faults or platform errors on out-of-range readl(). Uncorrectable-error handling itself can disable CXL.mem devices and force resets, impacting availability."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-29T06:21:47.605Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6fc1919a6f2ed541484dd1f6cd93374044f8fd3d"
        },
        {
          "url": "https://git.kernel.org/stable/c/fc5eb0962a5e50d64e711817cc24d67df2d90528"
        },
        {
          "url": "https://git.kernel.org/stable/c/c268f949e219f9e179558e836f457f6c5fbec416"
        }
      ],
      "title": "cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80662",
    "datePublished": "2026-08-28T06:49:06.277Z",
    "dateReserved": "2026-08-26T14:34:25.781Z",
    "dateUpdated": "2026-08-29T06:21:47.605Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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