Vulnerability-Lookup

GHSA-M8F2-RW7M-JRXF

Vulnerability from github – Published: 2026-01-14 15:33 – Updated: 2026-01-14 15:33

Details

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

mm/slub: reset KASAN tag in defer_free() before accessing freed memory

When CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free() before defer_free(). On ARM64 with MTE (Memory Tagging Extension), kasan_slab_free() poisons the memory and changes the tag from the original (e.g., 0xf3) to a poison tag (0xfe).

When defer_free() then tries to write to the freed object to build the deferred free list via llist_add(), the pointer still has the old tag, causing a tag mismatch and triggering a KASAN use-after-free report:

BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537 Write at addr f3f000000854f020 by task kworker/u8:6/983 Pointer tag: [f3], memory tag: [fe]

Fix this by calling kasan_reset_tag() before accessing the freed memory. This is safe because defer_free() is part of the allocator itself and is expected to manipulate freed memory for bookkeeping purposes.

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{
  "affected": [],
  "aliases": [
    "CVE-2025-71110"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-01-14T15:16:00Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slub: reset KASAN tag in defer_free() before accessing freed memory\n\nWhen CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free()\nbefore defer_free(). On ARM64 with MTE (Memory Tagging Extension),\nkasan_slab_free() poisons the memory and changes the tag from the\noriginal (e.g., 0xf3) to a poison tag (0xfe).\n\nWhen defer_free() then tries to write to the freed object to build the\ndeferred free list via llist_add(), the pointer still has the old tag,\ncausing a tag mismatch and triggering a KASAN use-after-free report:\n\n  BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537\n  Write at addr f3f000000854f020 by task kworker/u8:6/983\n  Pointer tag: [f3], memory tag: [fe]\n\nFix this by calling kasan_reset_tag() before accessing the freed memory.\nThis is safe because defer_free() is part of the allocator itself and is\nexpected to manipulate freed memory for bookkeeping purposes.",
  "id": "GHSA-m8f2-rw7m-jrxf",
  "modified": "2026-01-14T15:33:00Z",
  "published": "2026-01-14T15:33:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-71110"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/53ca00a19d345197a37a1bf552e8d1e7b091666c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/65d4e5af2a2e82f4fc50d8259aee208fbc6b2c1d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2025-71110 (GCVE-0-2025-71110)

Vulnerability from cvelistv5 – Published: 2026-01-14 15:05 – Updated: 2026-01-14 15:05

Title

mm/slub: reset KASAN tag in defer_free() before accessing freed memory

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/slub: reset KASAN tag in defer_free() before accessing freed memory When CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free() before defer_free(). On ARM64 with MTE (Memory Tagging Extension), kasan_slab_free() poisons the memory and changes the tag from the original (e.g., 0xf3) to a poison tag (0xfe). When defer_free() then tries to write to the freed object to build the deferred free list via llist_add(), the pointer still has the old tag, causing a tag mismatch and triggering a KASAN use-after-free report: BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537 Write at addr f3f000000854f020 by task kworker/u8:6/983 Pointer tag: [f3], memory tag: [fe] Fix this by calling kasan_reset_tag() before accessing the freed memory. This is safe because defer_free() is part of the allocator itself and is expected to manipulate freed memory for bookkeeping purposes.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/65d4e5af2a2e82f4f…
	https://git.kernel.org/stable/c/53ca00a19d345197a…

Impacted products

Vendor

Product

Version

Linux

Affected: af92793e52c3a99b828ed4bdd277fd3e11c18d08 , < 65d4e5af2a2e82f4fc50d8259aee208fbc6b2c1d (git)
Affected: af92793e52c3a99b828ed4bdd277fd3e11c18d08 , < 53ca00a19d345197a37a1bf552e8d1e7b091666c (git)

Linux

Affected: 6.18
Unaffected: 0 , < 6.18 (semver)
Unaffected: 6.18.3 , ≤ 6.18.* (semver)
Unaffected: 6.19-rc2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "mm/slub.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "65d4e5af2a2e82f4fc50d8259aee208fbc6b2c1d",
              "status": "affected",
              "version": "af92793e52c3a99b828ed4bdd277fd3e11c18d08",
              "versionType": "git"
            },
            {
              "lessThan": "53ca00a19d345197a37a1bf552e8d1e7b091666c",
              "status": "affected",
              "version": "af92793e52c3a99b828ed4bdd277fd3e11c18d08",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "mm/slub.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.18"
            },
            {
              "lessThan": "6.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19-rc2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.3",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19-rc2",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slub: reset KASAN tag in defer_free() before accessing freed memory\n\nWhen CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free()\nbefore defer_free(). On ARM64 with MTE (Memory Tagging Extension),\nkasan_slab_free() poisons the memory and changes the tag from the\noriginal (e.g., 0xf3) to a poison tag (0xfe).\n\nWhen defer_free() then tries to write to the freed object to build the\ndeferred free list via llist_add(), the pointer still has the old tag,\ncausing a tag mismatch and triggering a KASAN use-after-free report:\n\n  BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537\n  Write at addr f3f000000854f020 by task kworker/u8:6/983\n  Pointer tag: [f3], memory tag: [fe]\n\nFix this by calling kasan_reset_tag() before accessing the freed memory.\nThis is safe because defer_free() is part of the allocator itself and is\nexpected to manipulate freed memory for bookkeeping purposes."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-14T15:05:57.952Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/65d4e5af2a2e82f4fc50d8259aee208fbc6b2c1d"
        },
        {
          "url": "https://git.kernel.org/stable/c/53ca00a19d345197a37a1bf552e8d1e7b091666c"
        }
      ],
      "title": "mm/slub: reset KASAN tag in defer_free() before accessing freed memory",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-71110",
    "datePublished": "2026-01-14T15:05:57.952Z",
    "dateReserved": "2026-01-13T15:30:19.652Z",
    "dateUpdated": "2026-01-14T15:05:57.952Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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-M8F2-RW7M-JRXF

CVE-2025-71110 (GCVE-0-2025-71110)

Tags

Sightings

Nomenclature