Vulnerability-Lookup

FKIE_CVE-2026-80980

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-13 07:17

Severity

9.8 (Critical) - CVSS:3.1/AV:N/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: net/smc: stop killed, freed and out_of_sync sharing a byte The three connection state flags are single-bit bitfields, so they occupy one byte of struct smc_connection and every store to one is a read-modify-write of the other two: u8 killed : 1; u8 freed : 1; u8 out_of_sync : 1; They are not written under a common lock. smc_cdc_msg_validate() sets out_of_sync from the receive tasklet, while smc_conn_kill() sets killed from process context under lock_sock(), and the receive path does not defer to the backlog when the socket is owned -- smc_cdc_msg_recv() takes only bh_lock_sock(). Give each flag its own byte so a store no longer touches its neighbours. All readers test them as booleans and are unchanged. struct smc_connection grows by two bytes.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/313f79149eb337411c64e2c247234b62ef9a3cb9
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/db51a8658c11a82432b64999519a269c3aabb447

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/smc/smc.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "313f79149eb337411c64e2c247234b62ef9a3cb9",
              "status": "affected",
              "version": "b286a0651e4404ab96cdfdcdad8a839a26b3751e",
              "versionType": "git"
            },
            {
              "lessThan": "2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec",
              "status": "affected",
              "version": "b286a0651e4404ab96cdfdcdad8a839a26b3751e",
              "versionType": "git"
            },
            {
              "lessThan": "db51a8658c11a82432b64999519a269c3aabb447",
              "status": "affected",
              "version": "b286a0651e4404ab96cdfdcdad8a839a26b3751e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/smc/smc.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.8"
            },
            {
              "lessThan": "5.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "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\nnet/smc: stop killed, freed and out_of_sync sharing a byte\n\nThe three connection state flags are single-bit bitfields, so they occupy\none byte of struct smc_connection and every store to one is a\nread-modify-write of the other two:\n\n    u8  killed : 1;\n    u8  freed : 1;\n    u8  out_of_sync : 1;\n\nThey are not written under a common lock. smc_cdc_msg_validate() sets\nout_of_sync from the receive tasklet, while smc_conn_kill() sets killed\nfrom process context under lock_sock(), and the receive path does not defer\nto the backlog when the socket is owned -- smc_cdc_msg_recv() takes only\nbh_lock_sock().\n\nGive each flag its own byte so a store no longer touches its neighbours.\nAll readers test them as booleans and are unchanged. struct smc_connection\ngrows by two bytes."
    }
  ],
  "id": "CVE-2026-80980",
  "lastModified": "2026-09-13T07:17:04.887",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:04.407",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/313f79149eb337411c64e2c247234b62ef9a3cb9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/db51a8658c11a82432b64999519a269c3aabb447"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-80980 (GCVE-0-2026-80980)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:42 – Updated: 2026-09-13 06:28

Title

net/smc: stop killed, freed and out_of_sync sharing a byte

Summary

Severity

9.8 (Critical)


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

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/313f79149eb337411…
https://git.kernel.org/stable/c/2cb7a8d64b7e8ccdc…
https://git.kernel.org/stable/c/db51a8658c11a8243…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b286a0651e4404ab96cdfdcdad8a839a26b3751e , < 313f79149eb337411c64e2c247234b62ef9a3cb9 (git) Affected: b286a0651e4404ab96cdfdcdad8a839a26b3751e , < 2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec (git) Affected: b286a0651e4404ab96cdfdcdad8a839a26b3751e , < db51a8658c11a82432b64999519a269c3aabb447 (git)
Linux	Linux	Affected: 5.8 Unaffected: 0 , < 5.8 (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/smc/smc.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "313f79149eb337411c64e2c247234b62ef9a3cb9",
              "status": "affected",
              "version": "b286a0651e4404ab96cdfdcdad8a839a26b3751e",
              "versionType": "git"
            },
            {
              "lessThan": "2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec",
              "status": "affected",
              "version": "b286a0651e4404ab96cdfdcdad8a839a26b3751e",
              "versionType": "git"
            },
            {
              "lessThan": "db51a8658c11a82432b64999519a269c3aabb447",
              "status": "affected",
              "version": "b286a0651e4404ab96cdfdcdad8a839a26b3751e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/smc/smc.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.8"
            },
            {
              "lessThan": "5.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "5.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: stop killed, freed and out_of_sync sharing a byte\n\nThe three connection state flags are single-bit bitfields, so they occupy\none byte of struct smc_connection and every store to one is a\nread-modify-write of the other two:\n\n    u8  killed : 1;\n    u8  freed : 1;\n    u8  out_of_sync : 1;\n\nThey are not written under a common lock. smc_cdc_msg_validate() sets\nout_of_sync from the receive tasklet, while smc_conn_kill() sets killed\nfrom process context under lock_sock(), and the receive path does not defer\nto the backlog when the socket is owned -- smc_cdc_msg_recv() takes only\nbh_lock_sock().\n\nGive each flag its own byte so a store no longer touches its neighbours.\nAll readers test them as booleans and are unchanged. struct smc_connection\ngrows by two bytes."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - smc_cdc_msg_validate() runs from the SMC-R CDC receive tasklet on RDMA completions, and teardown is driven by CLC DECLINE (FIRST_CONTACT) or LLC DELETE_LINK_ALL from the same peer. SMC-Rv2 is RoCEv2 over UDP/4791 (IP-routable) with the CLC handshake on plain TCP, so a remote host that can reach an AF_SMC listener hits the path.\nAC:L - The attacker controls both sides of the race: it sends CDC failover_validation messages that store out_of_sync from the receive tasklet (no sock lock) while concurrently forcing smc_conn_kill()/smc_conn_free() via CLC decline, CDC close/abort, or LLC link-delete, and can retry across many connections in the same link group.\nPR:N - SMC has no peer authentication. Completing the CLC handshake to a listening AF_SMC/IPPROTO_SMC socket and sending CDC/CLC/LLC messages requires no credentials, capabilities, or local account, matching other SMC remote bugs.\nUI:N - CDC is processed in a softirq tasklet from the RDMA completion queue and CLC decline is handled in the handshake worker; no local user or application action is required beyond the already-listening SMC server.\nS:U - The corrupted flags and resulting UAF stay inside kernel objects (smc_connection, smc_sock, smc_link_group) in the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - A lost killed/freed/out_of_sync bit from the shared-byte RMW lets CDC continue after unregister or lets smc_conn_free() run twice (duplicate smc_lgr_put), a use-after-free of the socket and link group that can be reallocated to disclose kernel memory.\nI:H - The same UAF/double-free writes through a reused smc_sock (sk_err, sk_data_ready, queue_work on abort_work/close_work) and link-group refcounts, giving heap-spray primitives for arbitrary kernel write and control-flow hijack.\nA:H - Use-after-free and double-free of the connection and link group oops or panic in softirq/workqueue context (refcount underflow, as in related SMC UAFs), and the attacker can trigger it repeatedly without authentication."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-13T06:28:46.582Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/313f79149eb337411c64e2c247234b62ef9a3cb9"
        },
        {
          "url": "https://git.kernel.org/stable/c/2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec"
        },
        {
          "url": "https://git.kernel.org/stable/c/db51a8658c11a82432b64999519a269c3aabb447"
        }
      ],
      "title": "net/smc: stop killed, freed and out_of_sync sharing a byte",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80980",
    "datePublished": "2026-09-11T19:42:40.832Z",
    "dateReserved": "2026-08-26T14:34:25.811Z",
    "dateUpdated": "2026-09-13T06:28:46.582Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.