Vulnerability-Lookup

GHSA-5M64-3X43-VXJX

Vulnerability from github – Published: 2026-06-25 09:31 – Updated: 2026-06-28 09:31

Details

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

xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload

__input_process_payload() stores first_skb into xtfs->ra_newskb under drop_lock when starting partial reassembly, then unlocks and breaks out of the processing loop. The post-loop check reads xtfs->ra_newskb without the lock to decide whether first_skb is still owned:

if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb)

Between spin_unlock and this read, a concurrent CPU running iptfs_reassem_cont() (or the drop_timer hrtimer) can complete reassembly, NULL xtfs->ra_newskb, and free the skb. The check then evaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb operate on the freed skb — a use-after-free in skbuff_head_cache.

Replace the unlocked read with a local bool that records whether first_skb was handed to the reassembly state in the current call. The flag is set after the existing spin_unlock, before the break, using the pointer equality that is stable at that point (first_skb == skb iff first_skb was stored in ra_newskb).

Severity

8.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-53240"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-25T09:16:41Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix use-after-free on first_skb in __input_process_payload\n\n__input_process_payload() stores first_skb into xtfs-\u003era_newskb under\ndrop_lock when starting partial reassembly, then unlocks and breaks out\nof the processing loop. The post-loop check reads xtfs-\u003era_newskb\nwithout the lock to decide whether first_skb is still owned:\n\n    if (first_skb \u0026\u0026 first_iplen \u0026\u0026 !defer \u0026\u0026 first_skb != xtfs-\u003era_newskb)\n\nBetween spin_unlock and this read, a concurrent CPU running\niptfs_reassem_cont() (or the drop_timer hrtimer) can complete\nreassembly, NULL xtfs-\u003era_newskb, and free the skb. The check then\nevaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb\noperate on the freed skb \u2014 a use-after-free in skbuff_head_cache.\n\nReplace the unlocked read with a local bool that records whether\nfirst_skb was handed to the reassembly state in the current call. The\nflag is set after the existing spin_unlock, before the break, using the\npointer equality that is stable at that point (first_skb == skb iff\nfirst_skb was stored in ra_newskb).",
  "id": "GHSA-5m64-3x43-vxjx",
  "modified": "2026-06-28T09:31:46Z",
  "published": "2026-06-25T09:31:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53240"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8d9a79fbf5172d9c4c0146057af2360913265a11"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eb48730bb827d1550401a5d391903f9d90b493c8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-53240 (GCVE-0-2026-53240)

Vulnerability from cvelistv5 – Published: 2026-06-25 08:39 – Updated: 2026-06-28 06:40

Title

xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload

Summary

In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload __input_process_payload() stores first_skb into xtfs->ra_newskb under drop_lock when starting partial reassembly, then unlocks and breaks out of the processing loop. The post-loop check reads xtfs->ra_newskb without the lock to decide whether first_skb is still owned: if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb) Between spin_unlock and this read, a concurrent CPU running iptfs_reassem_cont() (or the drop_timer hrtimer) can complete reassembly, NULL xtfs->ra_newskb, and free the skb. The check then evaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb operate on the freed skb — a use-after-free in skbuff_head_cache. Replace the unlocked read with a local bool that records whether first_skb was handed to the reassembly state in the current call. The flag is set after the existing spin_unlock, before the break, using the pointer equality that is stable at that point (first_skb == skb iff first_skb was stored in ra_newskb).

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:N/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/8d9a79fbf5172d9c4…
https://git.kernel.org/stable/c/ff2ee35b6ce5fa8a8…
https://git.kernel.org/stable/c/eb48730bb827d1550…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3f3339885fb343b7b42d7c34717108ce07da24ae , < 8d9a79fbf5172d9c4c0146057af2360913265a11 (git) Affected: 3f3339885fb343b7b42d7c34717108ce07da24ae , < ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198 (git) Affected: 3f3339885fb343b7b42d7c34717108ce07da24ae , < eb48730bb827d1550401a5d391903f9d90b493c8 (git)
Linux	Linux	Affected: 6.14 Unaffected: 0 , < 6.14 (semver) Unaffected: 6.18.36 , ≤ 6.18.* (semver) Unaffected: 7.0.13 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_iptfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "8d9a79fbf5172d9c4c0146057af2360913265a11",
              "status": "affected",
              "version": "3f3339885fb343b7b42d7c34717108ce07da24ae",
              "versionType": "git"
            },
            {
              "lessThan": "ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198",
              "status": "affected",
              "version": "3f3339885fb343b7b42d7c34717108ce07da24ae",
              "versionType": "git"
            },
            {
              "lessThan": "eb48730bb827d1550401a5d391903f9d90b493c8",
              "status": "affected",
              "version": "3f3339885fb343b7b42d7c34717108ce07da24ae",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_iptfs.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": "6.18.36",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.36",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.13",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix use-after-free on first_skb in __input_process_payload\n\n__input_process_payload() stores first_skb into xtfs-\u003era_newskb under\ndrop_lock when starting partial reassembly, then unlocks and breaks out\nof the processing loop. The post-loop check reads xtfs-\u003era_newskb\nwithout the lock to decide whether first_skb is still owned:\n\n    if (first_skb \u0026\u0026 first_iplen \u0026\u0026 !defer \u0026\u0026 first_skb != xtfs-\u003era_newskb)\n\nBetween spin_unlock and this read, a concurrent CPU running\niptfs_reassem_cont() (or the drop_timer hrtimer) can complete\nreassembly, NULL xtfs-\u003era_newskb, and free the skb. The check then\nevaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb\noperate on the freed skb \u2014 a use-after-free in skbuff_head_cache.\n\nReplace the unlocked read with a local bool that records whether\nfirst_skb was handed to the reassembly state in the current call. The\nflag is set after the existing spin_unlock, before the break, using the\npointer equality that is stable at that point (first_skb == skb iff\nfirst_skb was stored in ra_newskb)."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-28T06:40:48.086Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/8d9a79fbf5172d9c4c0146057af2360913265a11"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198"
        },
        {
          "url": "https://git.kernel.org/stable/c/eb48730bb827d1550401a5d391903f9d90b493c8"
        }
      ],
      "title": "xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-53240",
    "datePublished": "2026-06-25T08:39:35.809Z",
    "dateReserved": "2026-06-09T07:44:35.393Z",
    "dateUpdated": "2026-06-28T06:40:48.086Z",
    "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.

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GHSA-5M64-3X43-VXJX

CVE-2026-53240 (GCVE-0-2026-53240)

Tags

Sightings

Nomenclature