Vulnerability-Lookup

GHSA-CHR7-RQMR-Q86R

Vulnerability from github – Published: 2026-04-02 12:31 – Updated: 2026-04-24 15:32

Details

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

futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()

During futex_key_to_node_opt() execution, vma->vm_policy is read under speculative mmap lock and RCU. Concurrently, mbind() may call vma_replace_policy() which frees the old mempolicy immediately via kmem_cache_free().

This creates a race where __futex_key_to_node() dereferences a freed mempolicy pointer, causing a use-after-free read of mpol->mode.

[ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349) [ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87

[ 151.415969] Call Trace:

[ 151.416732] __asan_load2 (mm/kasan/generic.c:271) [ 151.416777] __futex_key_to_node (kernel/futex/core.c:349) [ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)

Fix by adding rcu to __mpol_put().

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-2026-23415"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-02T12:16:20Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()\n\nDuring futex_key_to_node_opt() execution, vma-\u003evm_policy is read under\nspeculative mmap lock and RCU. Concurrently, mbind() may call\nvma_replace_policy() which frees the old mempolicy immediately via\nkmem_cache_free().\n\nThis creates a race where __futex_key_to_node() dereferences a freed\nmempolicy pointer, causing a use-after-free read of mpol-\u003emode.\n\n[  151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)\n[  151.414046] Read of size 2 at addr ffff888001c49634 by task e/87\n\n[  151.415969] Call Trace:\n\n[  151.416732]  __asan_load2 (mm/kasan/generic.c:271)\n[  151.416777]  __futex_key_to_node (kernel/futex/core.c:349)\n[  151.416822]  get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)\n\nFix by adding rcu to __mpol_put().",
  "id": "GHSA-chr7-rqmr-q86r",
  "modified": "2026-04-24T15:32:20Z",
  "published": "2026-04-02T12:31:05Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23415"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/190a8c48ff623c3d67cb295b4536a660db2012aa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7e196194ea27bd49adf3551e2aceb83498eb73fe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/853f70c67d1b37e368fdcb3e328c4b8c04f53ac0"
    }
  ],
  "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-2026-23415 (GCVE-0-2026-23415)

Vulnerability from cvelistv5 – Published: 2026-04-02 11:40 – Updated: 2026-04-27 14:02

Title

futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()

Summary

In the Linux kernel, the following vulnerability has been resolved: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy() During futex_key_to_node_opt() execution, vma->vm_policy is read under speculative mmap lock and RCU. Concurrently, mbind() may call vma_replace_policy() which frees the old mempolicy immediately via kmem_cache_free(). This creates a race where __futex_key_to_node() dereferences a freed mempolicy pointer, causing a use-after-free read of mpol->mode. [ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349) [ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87 [ 151.415969] Call Trace: [ 151.416732] __asan_load2 (mm/kasan/generic.c:271) [ 151.416777] __futex_key_to_node (kernel/futex/core.c:349) [ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593) Fix by adding rcu to __mpol_put().

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

URL

Tags

	https://git.kernel.org/stable/c/853f70c67d1b37e36…
	https://git.kernel.org/stable/c/7e196194ea27bd49a…
	https://git.kernel.org/stable/c/190a8c48ff623c3d6…

Impacted products

Vendor

Product

Version

Linux

Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 853f70c67d1b37e368fdcb3e328c4b8c04f53ac0 (git)
Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 7e196194ea27bd49adf3551e2aceb83498eb73fe (git)
Affected: c042c505210dc3453f378df432c10fff3d471bc5 , < 190a8c48ff623c3d67cb295b4536a660db2012aa (git)

Linux

Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.21 , ≤ 6.18.* (semver)
Unaffected: 6.19.11 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/mempolicy.h",
            "kernel/futex/core.c",
            "mm/mempolicy.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "853f70c67d1b37e368fdcb3e328c4b8c04f53ac0",
              "status": "affected",
              "version": "c042c505210dc3453f378df432c10fff3d471bc5",
              "versionType": "git"
            },
            {
              "lessThan": "7e196194ea27bd49adf3551e2aceb83498eb73fe",
              "status": "affected",
              "version": "c042c505210dc3453f378df432c10fff3d471bc5",
              "versionType": "git"
            },
            {
              "lessThan": "190a8c48ff623c3d67cb295b4536a660db2012aa",
              "status": "affected",
              "version": "c042c505210dc3453f378df432c10fff3d471bc5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/linux/mempolicy.h",
            "kernel/futex/core.c",
            "mm/mempolicy.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.21",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.21",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.11",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()\n\nDuring futex_key_to_node_opt() execution, vma-\u003evm_policy is read under\nspeculative mmap lock and RCU. Concurrently, mbind() may call\nvma_replace_policy() which frees the old mempolicy immediately via\nkmem_cache_free().\n\nThis creates a race where __futex_key_to_node() dereferences a freed\nmempolicy pointer, causing a use-after-free read of mpol-\u003emode.\n\n[  151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)\n[  151.414046] Read of size 2 at addr ffff888001c49634 by task e/87\n\n[  151.415969] Call Trace:\n\n[  151.416732]  __asan_load2 (mm/kasan/generic.c:271)\n[  151.416777]  __futex_key_to_node (kernel/futex/core.c:349)\n[  151.416822]  get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)\n\nFix by adding rcu to __mpol_put()."
        }
      ],
      "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": "2026-04-27T14:02:14.037Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/853f70c67d1b37e368fdcb3e328c4b8c04f53ac0"
        },
        {
          "url": "https://git.kernel.org/stable/c/7e196194ea27bd49adf3551e2aceb83498eb73fe"
        },
        {
          "url": "https://git.kernel.org/stable/c/190a8c48ff623c3d67cb295b4536a660db2012aa"
        }
      ],
      "title": "futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23415",
    "datePublished": "2026-04-02T11:40:56.476Z",
    "dateReserved": "2026-01-13T15:37:46.014Z",
    "dateUpdated": "2026-04-27T14:02:14.037Z",
    "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.

Action not permitted

GHSA-CHR7-RQMR-Q86R

CVE-2026-23415 (GCVE-0-2026-23415)

Tags

Sightings

Nomenclature