Vulnerability-Lookup

GHSA-P635-M8R7-FC75

Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-19 18:32

Details

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

net/af_iucv: fix NULL deref in afiucv_hs_callback_syn()

afiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC. If the allocation fails, nsk is NULL.

The connection-refused path is entered when the listen state check fails, the accept backlog is full, or nsk is NULL. The code unconditionally calls iucv_sock_kill(nsk) in that path.

iucv_sock_kill() does not accept a NULL socket pointer and immediately dereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL, calling iucv_sock_kill(nsk) results in a NULL pointer dereference.

Only call iucv_sock_kill() when a child socket was successfully allocated.

Severity

7.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-68141"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T13:19:59Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/af_iucv: fix NULL deref in afiucv_hs_callback_syn()\n\nafiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC.\nIf the allocation fails, nsk is NULL.\n\nThe connection-refused path is entered when the listen state check\nfails, the accept backlog is full, or nsk is NULL. The code\nunconditionally calls iucv_sock_kill(nsk) in that path.\n\niucv_sock_kill() does not accept a NULL socket pointer and immediately\ndereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL,\ncalling iucv_sock_kill(nsk) results in a NULL pointer dereference.\n\nOnly call iucv_sock_kill() when a child socket was successfully\nallocated.",
  "id": "GHSA-p635-m8r7-fc75",
  "modified": "2026-08-19T18:32:06Z",
  "published": "2026-08-10T15:33:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68141"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/07e21deb3664001995e0a456dd627ab7dbe127ec"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0e857185591fe79934427c9c0c1c31dc776be134"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/33736ff5e7c97d3348ce812e8bd2e125d840743c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/46453b16f38ec7147351f7447e2aec6ea330f7b3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/47a5116e56a6b6fe1e909f244e39cd0fc26ceee4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6a1eb5b46c19073f8153b7e2c19b408cf353aaf1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8bb111f87ded6acb9837ec9b45d6f02cda94c51f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c0b6e2ae90613c2fea7eaf3faa20985c6c2a1953"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-68141 (GCVE-0-2026-68141)

Vulnerability from cvelistv5 – Published: 2026-08-10 11:59 – Updated: 2026-08-19 16:29

Title

net/af_iucv: fix NULL deref in afiucv_hs_callback_syn()

Summary

In the Linux kernel, the following vulnerability has been resolved: net/af_iucv: fix NULL deref in afiucv_hs_callback_syn() afiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC. If the allocation fails, nsk is NULL. The connection-refused path is entered when the listen state check fails, the accept backlog is full, or nsk is NULL. The code unconditionally calls iucv_sock_kill(nsk) in that path. iucv_sock_kill() does not accept a NULL socket pointer and immediately dereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL, calling iucv_sock_kill(nsk) results in a NULL pointer dereference. Only call iucv_sock_kill() when a child socket was successfully allocated.

Severity

7.5 (High)


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

Assigner

Linux mitre root Scorecard

References

8 references

URL	Tags
https://git.kernel.org/stable/c/6a1eb5b46c19073f8…
https://git.kernel.org/stable/c/c0b6e2ae90613c2fe…
https://git.kernel.org/stable/c/07e21deb366400199…
https://git.kernel.org/stable/c/8bb111f87ded6acb9…
https://git.kernel.org/stable/c/46453b16f38ec7147…
https://git.kernel.org/stable/c/33736ff5e7c97d334…
https://git.kernel.org/stable/c/0e857185591fe7993…
https://git.kernel.org/stable/c/47a5116e56a6b6fe1…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3881ac441f642d56503818123446f7298442236b , < 6a1eb5b46c19073f8153b7e2c19b408cf353aaf1 (git) Affected: 3881ac441f642d56503818123446f7298442236b , < c0b6e2ae90613c2fea7eaf3faa20985c6c2a1953 (git) Affected: 3881ac441f642d56503818123446f7298442236b , < 07e21deb3664001995e0a456dd627ab7dbe127ec (git) Affected: 3881ac441f642d56503818123446f7298442236b , < 8bb111f87ded6acb9837ec9b45d6f02cda94c51f (git) Affected: 3881ac441f642d56503818123446f7298442236b , < 46453b16f38ec7147351f7447e2aec6ea330f7b3 (git) Affected: 3881ac441f642d56503818123446f7298442236b , < 33736ff5e7c97d3348ce812e8bd2e125d840743c (git) Affected: 3881ac441f642d56503818123446f7298442236b , < 0e857185591fe79934427c9c0c1c31dc776be134 (git) Affected: 3881ac441f642d56503818123446f7298442236b , < 47a5116e56a6b6fe1e909f244e39cd0fc26ceee4 (git)
Linux	Linux	Affected: 3.2 Unaffected: 0 , < 3.2 (semver) Unaffected: 5.10.265 , ≤ 5.10.* (semver) Unaffected: 5.15.216 , ≤ 5.15.* (semver) Unaffected: 6.1.183 , ≤ 6.1.* (semver) Unaffected: 6.6.148 , ≤ 6.6.* (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/iucv/af_iucv.c"
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          "versions": [
            {
              "lessThan": "6a1eb5b46c19073f8153b7e2c19b408cf353aaf1",
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              "versionType": "git"
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              "lessThan": "c0b6e2ae90613c2fea7eaf3faa20985c6c2a1953",
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              "versionType": "git"
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              "lessThan": "07e21deb3664001995e0a456dd627ab7dbe127ec",
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              "version": "3881ac441f642d56503818123446f7298442236b",
              "versionType": "git"
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              "lessThan": "8bb111f87ded6acb9837ec9b45d6f02cda94c51f",
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              "versionType": "git"
            },
            {
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.2"
            },
            {
              "lessThan": "3.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
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              "versionType": "semver"
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            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
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            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
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              "versionType": "semver"
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              "lessThanOrEqual": "7.1.*",
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            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
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              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
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        {
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/af_iucv: fix NULL deref in afiucv_hs_callback_syn()\n\nafiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC.\nIf the allocation fails, nsk is NULL.\n\nThe connection-refused path is entered when the listen state check\nfails, the accept backlog is full, or nsk is NULL. The code\nunconditionally calls iucv_sock_kill(nsk) in that path.\n\niucv_sock_kill() does not accept a NULL socket pointer and immediately\ndereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL,\ncalling iucv_sock_kill(nsk) results in a NULL pointer dereference.\n\nOnly call iucv_sock_kill() when a child socket was successfully\nallocated."
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
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              "value": "AV:N - The flaw is reached from afiucv_hs_rcv() via dev_add_pack() when ETH_P_AF_IUCV SYN frames arrive on a HiperSockets netdev in netif RX softirq; a remote LPAR/guest on the IBM Z HiperSockets fabric can send these connection requests without local access.\nAC:L - An attacker can repeatedly send SYN packets to a listening AF_IUCV service to pressure GFP_ATOMIC socket allocations until iucv_sock_alloc() fails and the broken connection-refused path runs; no timing race or victim-specific state beyond routine memory pressure is required.\nPR:N - Exploitation requires only sending unauthenticated HiperSockets SYN traffic to a bound/listening AF_IUCV socket; the handshake path has no credential checks and the af_iucv code performs no capability or permission validation before reaching afiucv_hs_callback_syn().\nUI:N - Triggering the NULL dereference needs no action from an end user beyond a service already listening on HiperSockets; the attacker can initiate SYN packets remotely without victim interaction.\nS:U - Impact is a kernel NULL pointer dereference and likely oops/panic in the victim LPAR kernel; it does not cross a VM/host, IOMMU, or sandbox boundary to compromise a different security authority.\nC:N - The failure is an immediate NULL pointer dereference in sock_flag() inside iucv_sock_kill(); there is no memory corruption, out-of-bounds access, or use-after-free that could yield information disclosure.\nI:N - The bug does not write attacker-controlled data or corrupt kernel structures; it only dereferences a NULL socket pointer during cleanup, so no integrity impact or code-execution primitive is created.\nA:H - A NULL dereference in afiucv_hs_callback_syn() during softirq packet processing can cause a kernel oops or panic, denying all service on the affected IBM Z LPAR until reboot."
            }
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        "dateUpdated": "2026-08-19T16:29:59.584Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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        },
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      "title": "net/af_iucv: fix NULL deref in afiucv_hs_callback_syn()",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68141",
    "datePublished": "2026-08-10T11:59:05.051Z",
    "dateReserved": "2026-07-30T09:28:09.370Z",
    "dateUpdated": "2026-08-19T16:29:59.584Z",
    "state": "PUBLISHED"
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  "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.

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.

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GHSA-P635-M8R7-FC75

CVE-2026-68141 (GCVE-0-2026-68141)

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Sightings

Nomenclature

Related by attack behaviour