Vulnerability-Lookup

FKIE_CVE-2026-72151

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18

Severity

8.4 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt tpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls crypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret() without installing a completion callback, discards both return values, and immediately frees the kpp_request via kpp_request_free(). When the resolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE, keembay-ocs), either operation returns -EINPROGRESS and the deferred completion worker dereferences the freed request. The path fires automatically from the hwrng_fillfn kernel thread via tpm_get_random -> tpm2_get_random -> tpm2_start_auth_session -> tpm_buf_append_salt on every entropy poll, without any userland action. Install crypto_req_done as the completion callback, wrap both KPP operations in crypto_wait_req(), and propagate errors to the caller. The wait is a no-op for synchronous backends.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/111e520efbe82b324bc42b1999b723c0619eea6d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/493333f167926c7adab8e7563e21ad71d8af84fa
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/73851a7c43dfa52d2ed9415889b33daf85da0ed9
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/934d1cd40e2893bf7a041b54f6afd1c008d7a21c

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/char/tpm/tpm2-sessions.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "111e520efbe82b324bc42b1999b723c0619eea6d",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            },
            {
              "lessThan": "934d1cd40e2893bf7a041b54f6afd1c008d7a21c",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            },
            {
              "lessThan": "493333f167926c7adab8e7563e21ad71d8af84fa",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            },
            {
              "lessThan": "73851a7c43dfa52d2ed9415889b33daf85da0ed9",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/char/tpm/tpm2-sessions.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "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\ntpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt\n\ntpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls\ncrypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret()\nwithout installing a completion callback, discards both return values,\nand immediately frees the kpp_request via kpp_request_free(). When the\nresolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE,\nkeembay-ocs), either operation returns -EINPROGRESS and the deferred\ncompletion worker dereferences the freed request.\n\nThe path fires automatically from the hwrng_fillfn kernel thread via\ntpm_get_random -\u003e tpm2_get_random -\u003e tpm2_start_auth_session -\u003e\ntpm_buf_append_salt on every entropy poll, without any userland action.\n\nInstall crypto_req_done as the completion callback, wrap both KPP\noperations in crypto_wait_req(), and propagate errors to the caller.\nThe wait is a no-op for synchronous backends."
    }
  ],
  "id": "CVE-2026-72151",
  "lastModified": "2026-08-17T06:18:15.263",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T06:21:32.823",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/111e520efbe82b324bc42b1999b723c0619eea6d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/493333f167926c7adab8e7563e21ad71d8af84fa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/73851a7c43dfa52d2ed9415889b33daf85da0ed9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/934d1cd40e2893bf7a041b54f6afd1c008d7a21c"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-72151 (GCVE-0-2026-72151)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:53 – Updated: 2026-08-17 05:41

Title

tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt

Summary

Severity

8.4 (High)


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

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/111e520efbe82b324…
https://git.kernel.org/stable/c/934d1cd40e2893bf7…
https://git.kernel.org/stable/c/493333f167926c7ad…
https://git.kernel.org/stable/c/73851a7c43dfa52d2…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1085b8276bb4239daa7008f0dcd5c973e4bd690f , < 111e520efbe82b324bc42b1999b723c0619eea6d (git) Affected: 1085b8276bb4239daa7008f0dcd5c973e4bd690f , < 934d1cd40e2893bf7a041b54f6afd1c008d7a21c (git) Affected: 1085b8276bb4239daa7008f0dcd5c973e4bd690f , < 493333f167926c7adab8e7563e21ad71d8af84fa (git) Affected: 1085b8276bb4239daa7008f0dcd5c973e4bd690f , < 73851a7c43dfa52d2ed9415889b33daf85da0ed9 (git)
Linux	Linux	Affected: 6.10 Unaffected: 0 , < 6.10 (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/char/tpm/tpm2-sessions.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "111e520efbe82b324bc42b1999b723c0619eea6d",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            },
            {
              "lessThan": "934d1cd40e2893bf7a041b54f6afd1c008d7a21c",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            },
            {
              "lessThan": "493333f167926c7adab8e7563e21ad71d8af84fa",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            },
            {
              "lessThan": "73851a7c43dfa52d2ed9415889b33daf85da0ed9",
              "status": "affected",
              "version": "1085b8276bb4239daa7008f0dcd5c973e4bd690f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/char/tpm/tpm2-sessions.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "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"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt\n\ntpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls\ncrypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret()\nwithout installing a completion callback, discards both return values,\nand immediately frees the kpp_request via kpp_request_free(). When the\nresolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE,\nkeembay-ocs), either operation returns -EINPROGRESS and the deferred\ncompletion worker dereferences the freed request.\n\nThe path fires automatically from the hwrng_fillfn kernel thread via\ntpm_get_random -\u003e tpm2_get_random -\u003e tpm2_start_auth_session -\u003e\ntpm_buf_append_salt on every entropy poll, without any userland action.\n\nInstall crypto_req_done as the completion callback, wrap both KPP\noperations in crypto_wait_req(), and propagate errors to the caller.\nThe wait is a no-op for synchronous backends."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable code is reached only via local kernel TPM/HWRNG paths (hwrng_fillfn kernel thread polling tpm_get_random, or local /dev/hwrng reads); there is no network, adjacent-radio, or physical-access entry point to tpm_buf_append_salt.\nAC:L - On affected builds (CONFIG_TCG_TPM2_HMAC plus an async ecdh-nist-p256 backend), the UAF is deterministically triggered each auth-session setup without winning a race; async KPP returns -EINPROGRESS and the completion worker later dereferences the already-freed kpp_request.\nPR:N - No attacker credentials are required: the hwrng kernel thread invokes tpm2_start_auth_session automatically on TPM RNG polls, and unprivileged local processes can also reach tpm_get_random via /dev/hwrng without root or namespaced admin capabilities.\nUI:N - Exploitation does not require any victim user action such as mounting a filesystem or opening a file; the bug fires from background kernel entropy collection and TPM session setup without interactive steps.\nS:U - Impact is confined to kernel memory integrity and availability on the same host; it is a standard kernel heap UAF, not a cross-boundary escape such as guest-to-host VM breakout or IOMMU/DMA bypass.\nC:H - Use-after-free of a kmalloc\u0027d kpp_request lets an attacker influence freed heap contents and potentially obtain arbitrary kernel memory read primitives through heap grooming, not merely a bounded leak.\nI:H - The UAF corrupts kernel heap metadata/object lifetimes and can be leveraged for arbitrary write or control-flow hijack (privilege escalation), not just limited or transient data modification.\nA:H - The deferred crypto completion dereferences freed memory, causing kernel oops/panic or hang during normal TPM RNG polling, yielding complete loss of system availability on affected hardware."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:41:00.459Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/111e520efbe82b324bc42b1999b723c0619eea6d"
        },
        {
          "url": "https://git.kernel.org/stable/c/934d1cd40e2893bf7a041b54f6afd1c008d7a21c"
        },
        {
          "url": "https://git.kernel.org/stable/c/493333f167926c7adab8e7563e21ad71d8af84fa"
        },
        {
          "url": "https://git.kernel.org/stable/c/73851a7c43dfa52d2ed9415889b33daf85da0ed9"
        }
      ],
      "title": "tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72151",
    "datePublished": "2026-08-15T05:53:22.196Z",
    "dateReserved": "2026-08-09T03:40:39.908Z",
    "dateUpdated": "2026-08-17T05:41:00.459Z",
    "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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

FKIE_CVE-2026-72151

CVE-2026-72151 (GCVE-0-2026-72151)

Tags

Sightings

Nomenclature