GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

FKIE_CVE-2026-80602

Vulnerability from fkie_nvd - Published: 2026-08-28 08:16 - Updated: 2026-08-28 08:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: perf/x86/amd/lbr: Fix kernel address leakage A user-only branch stack can contain branches that originate from the kernel. As a result, kernel addresses are exposed to user space even when PERF_SAMPLE_BRANCH_USER is requested. On AMD processors supporting X86_FEATURE_AMD_LBR_V2, perf can still report SYSRET/ERET entries for which the branch-from addresses are in the kernel. E.g. $ perf record -e cycles -o - -j any,save_type,u -- \ perf bench syscall basic --loop 1000 | \ perf script -i - -F brstack|tr ' ' '\n'| \ grep -E '0x[89a-f][0-9a-f]{15}' ... 0xffffffff81001268/0x717a90a38f1a/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a39157/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a2c628/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a41b60/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a8bef1c30/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a8e4d3c90/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH ... The reason is that the hardware filter only considers the privilege level applicable to the branch target. Extend software filtering to also validate the branch-from addresses against br_sel, so that any branch record whose branch-from address is in the kernel is dropped when PERF_SAMPLE_BRANCH_USER is requested.
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/events/amd/lbr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5be478c1e08981ca91b34de310d7e2638171d9d8",
              "status": "affected",
              "version": "f4f925dae7419fc7a10af539c073871927ce3a24",
              "versionType": "git"
            },
            {
              "lessThan": "208ecca408b1707ad86ea247d3d3e09d3606fc13",
              "status": "affected",
              "version": "f4f925dae7419fc7a10af539c073871927ce3a24",
              "versionType": "git"
            },
            {
              "lessThan": "5ab0eba9c8819506bcb72348fd701f8a9006f95e",
              "status": "affected",
              "version": "f4f925dae7419fc7a10af539c073871927ce3a24",
              "versionType": "git"
            },
            {
              "lessThan": "fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f",
              "status": "affected",
              "version": "f4f925dae7419fc7a10af539c073871927ce3a24",
              "versionType": "git"
            },
            {
              "lessThan": "2a892294b83f541115c94b0bb637f39bef187657",
              "status": "affected",
              "version": "f4f925dae7419fc7a10af539c073871927ce3a24",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/events/amd/lbr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "lessThan": "6.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "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\nperf/x86/amd/lbr: Fix kernel address leakage\n\nA user-only branch stack can contain branches that originate from\nthe kernel. As a result, kernel addresses are exposed to user space\neven when PERF_SAMPLE_BRANCH_USER is requested. On AMD processors\nsupporting X86_FEATURE_AMD_LBR_V2, perf can still report SYSRET/ERET\nentries for which the branch-from addresses are in the kernel.\n\nE.g.\n\n  $ perf record -e cycles -o - -j any,save_type,u -- \\\n        perf bench syscall basic --loop 1000 | \\\n        perf script -i - -F brstack|tr \u0027 \u0027 \u0027\\n\u0027| \\\n        grep -E \u00270x[89a-f][0-9a-f]{15}\u0027\n\n  ...\n  0xffffffff81001268/0x717a90a38f1a/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a39157/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a2c628/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a41b60/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a8bef1c30/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a8e4d3c90/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  ...\n\nThe reason is that the hardware filter only considers the privilege\nlevel applicable to the branch target. Extend software filtering to\nalso validate the branch-from addresses against br_sel, so that any\nbranch record whose branch-from address is in the kernel is dropped\nwhen PERF_SAMPLE_BRANCH_USER is requested."
    }
  ],
  "id": "CVE-2026-80602",
  "lastModified": "2026-08-28T08:16:44.070",
  "metrics": {},
  "published": "2026-08-28T08:16:44.070",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/208ecca408b1707ad86ea247d3d3e09d3606fc13"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2a892294b83f541115c94b0bb637f39bef187657"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5ab0eba9c8819506bcb72348fd701f8a9006f95e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5be478c1e08981ca91b34de310d7e2638171d9d8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.


Loading…