Vulnerability-Lookup

GHSA-643V-C574-JXR9

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-27 06:30

Details

In the Linux kernel, the following vulnerability has been resolved:

perf/aux: Fix page UAF in map_range()

map_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via perf_mmap_to_page() while holding only event->mmap_mutex. Those fields are serialized by rb->aux_mutex, and mmap_mutex is per event.

Thus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race rb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows:

CPU 0 CPU 1 ===== ===== rb_alloc_aux() map_range() [1]: allocate rb->aux_pages[0]

                              [3]: perf_mmap_to_page()
                                     returns rb->aux_pages[0]
                              [4]: map it as VM_PFNMAP

[5]: rb->aux_pgoff = 1

munmap the page [6]: free rb->aux_pages[0]

Pages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a mapping to a freed physical frame.

Fix this by taking rb->aux_mutex across the page walk in map_range().

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64300"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:10Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/aux: Fix page UAF in map_range()\n\nmap_range() reads rb-\u003eaux_pages[], rb-\u003eaux_nr_pages and rb-\u003eaux_pgoff via\nperf_mmap_to_page() while holding only event-\u003emmap_mutex. Those fields are\nserialized by rb-\u003eaux_mutex, and mmap_mutex is per event.\n\nThus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race\nrb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows:\n\n  CPU 0                           CPU 1\n  =====                           =====\n  rb_alloc_aux()                  map_range()\n  [1]: allocate rb-\u003eaux_pages[0]\n  [2]: rb-\u003eaux_nr_pages++\n                                  [3]: perf_mmap_to_page()\n                                         returns rb-\u003eaux_pages[0]\n                                  [4]: map it as VM_PFNMAP\n  [5]: rb-\u003eaux_pgoff = 1\n\n  munmap the page\n  [6]: free rb-\u003eaux_pages[0]\n\nPages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a\nmapping to a freed physical frame.\n\nFix this by taking rb-\u003eaux_mutex across the page walk in map_range().",
  "id": "GHSA-643v-c574-jxr9",
  "modified": "2026-07-27T06:30:31Z",
  "published": "2026-07-25T12:31:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64300"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0cff05bd2186020f8706233e261016d149cc24db"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5948aaf64f81f217a25dcc2bf6c0779bca19566c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c8b7e113f7b61eef2f017e6329c27c2331058c5a"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64300 (GCVE-0-2026-64300)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-07-27 04:59

Title

perf/aux: Fix page UAF in map_range()

Summary

In the Linux kernel, the following vulnerability has been resolved: perf/aux: Fix page UAF in map_range() map_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via perf_mmap_to_page() while holding only event->mmap_mutex. Those fields are serialized by rb->aux_mutex, and mmap_mutex is per event. Thus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race rb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows: CPU 0 CPU 1 ===== ===== rb_alloc_aux() map_range() [1]: allocate rb->aux_pages[0] [2]: rb->aux_nr_pages++ [3]: perf_mmap_to_page() returns rb->aux_pages[0] [4]: map it as VM_PFNMAP [5]: rb->aux_pgoff = 1 munmap the page [6]: free rb->aux_pages[0] Pages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a mapping to a freed physical frame. Fix this by taking rb->aux_mutex across the page walk in map_range().

Severity

7.8 (High)


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

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/c8b7e113f7b61eef2…
https://git.kernel.org/stable/c/0cff05bd2186020f8…
https://git.kernel.org/stable/c/5948aaf64f81f217a…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b709eb872e19a19607bbb6d2975bc264d59735cf , < c8b7e113f7b61eef2f017e6329c27c2331058c5a (git) Affected: b709eb872e19a19607bbb6d2975bc264d59735cf , < 0cff05bd2186020f8706233e261016d149cc24db (git) Affected: b709eb872e19a19607bbb6d2975bc264d59735cf , < 5948aaf64f81f217a25dcc2bf6c0779bca19566c (git)
Linux	Linux	Affected: 6.14 Unaffected: 0 , < 6.14 (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/events/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c8b7e113f7b61eef2f017e6329c27c2331058c5a",
              "status": "affected",
              "version": "b709eb872e19a19607bbb6d2975bc264d59735cf",
              "versionType": "git"
            },
            {
              "lessThan": "0cff05bd2186020f8706233e261016d149cc24db",
              "status": "affected",
              "version": "b709eb872e19a19607bbb6d2975bc264d59735cf",
              "versionType": "git"
            },
            {
              "lessThan": "5948aaf64f81f217a25dcc2bf6c0779bca19566c",
              "status": "affected",
              "version": "b709eb872e19a19607bbb6d2975bc264d59735cf",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/events/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/aux: Fix page UAF in map_range()\n\nmap_range() reads rb-\u003eaux_pages[], rb-\u003eaux_nr_pages and rb-\u003eaux_pgoff via\nperf_mmap_to_page() while holding only event-\u003emmap_mutex. Those fields are\nserialized by rb-\u003eaux_mutex, and mmap_mutex is per event.\n\nThus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race\nrb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows:\n\n  CPU 0                           CPU 1\n  =====                           =====\n  rb_alloc_aux()                  map_range()\n  [1]: allocate rb-\u003eaux_pages[0]\n  [2]: rb-\u003eaux_nr_pages++\n                                  [3]: perf_mmap_to_page()\n                                         returns rb-\u003eaux_pages[0]\n                                  [4]: map it as VM_PFNMAP\n  [5]: rb-\u003eaux_pgoff = 1\n\n  munmap the page\n  [6]: free rb-\u003eaux_pages[0]\n\nPages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a\nmapping to a freed physical frame.\n\nFix this by taking rb-\u003eaux_mutex across the page walk in map_range()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-27T04:59:34.711Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/c8b7e113f7b61eef2f017e6329c27c2331058c5a"
        },
        {
          "url": "https://git.kernel.org/stable/c/0cff05bd2186020f8706233e261016d149cc24db"
        },
        {
          "url": "https://git.kernel.org/stable/c/5948aaf64f81f217a25dcc2bf6c0779bca19566c"
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      ],
      "title": "perf/aux: Fix page UAF in map_range()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64300",
    "datePublished": "2026-07-25T08:49:36.372Z",
    "dateReserved": "2026-07-19T15:36:31.778Z",
    "dateUpdated": "2026-07-27T04:59:34.711Z",
    "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.

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GHSA-643V-C574-JXR9

CVE-2026-64300 (GCVE-0-2026-64300)

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Nomenclature