Vulnerability-Lookup

GHSA-F2P8-HWVR-FWMQ

Vulnerability from github – Published: 2026-08-22 18:30 – Updated: 2026-08-25 06:31

Details

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

s390/ism: Fix UAF of sba and ieq during ism_dev_exit()

A ism interrupt handler can be active in parallel with ism_dev_exit(), accessing freed data structures.

No new interrupts will be generated after unregister_ieq(). Drain ongoing interrupt handlers by free_irq(), before freeing ism data structures.

Severity

8.4 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74690"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-22T16:16:43Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ism: Fix UAF of sba and ieq during ism_dev_exit()\n\nA ism interrupt handler can be active in parallel with ism_dev_exit(),\naccessing freed data structures.\n\nNo new interrupts will be generated after unregister_ieq(). Drain ongoing\ninterrupt handlers by free_irq(), before freeing ism data structures.",
  "id": "GHSA-f2p8-hwvr-fwmq",
  "modified": "2026-08-25T06:31:28Z",
  "published": "2026-08-22T18:30:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74690"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/774394d27930ec4cf4cb3eed8ab6a4d20cb2430a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b1896543ce59c4258625a35cf41e23a9a1f80ea2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc3021284050ecb3bba8a7851340cedcb5037928"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74690 (GCVE-0-2026-74690)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:32 – Updated: 2026-08-25 05:41

Title

s390/ism: Fix UAF of sba and ieq during ism_dev_exit()

Summary

In the Linux kernel, the following vulnerability has been resolved: s390/ism: Fix UAF of sba and ieq during ism_dev_exit() A ism interrupt handler can be active in parallel with ism_dev_exit(), accessing freed data structures. No new interrupts will be generated after unregister_ieq(). Drain ongoing interrupt handlers by free_irq(), before freeing ism data structures.

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

3 references

URL	Tags
https://git.kernel.org/stable/c/fc3021284050ecb3b…
https://git.kernel.org/stable/c/774394d27930ec4cf…
https://git.kernel.org/stable/c/b1896543ce59c4258…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 684b89bc39ce4f204b1a2b180f39f2eb36a6b695 , < fc3021284050ecb3bba8a7851340cedcb5037928 (git) Affected: 684b89bc39ce4f204b1a2b180f39f2eb36a6b695 , < 774394d27930ec4cf4cb3eed8ab6a4d20cb2430a (git) Affected: 684b89bc39ce4f204b1a2b180f39f2eb36a6b695 , < b1896543ce59c4258625a35cf41e23a9a1f80ea2 (git)
Linux	Linux	Affected: 4.19 Unaffected: 0 , < 4.19 (semver) Unaffected: 6.18.45 , ≤ 6.18.* (semver) Unaffected: 7.1.9 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/s390/net/ism_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fc3021284050ecb3bba8a7851340cedcb5037928",
              "status": "affected",
              "version": "684b89bc39ce4f204b1a2b180f39f2eb36a6b695",
              "versionType": "git"
            },
            {
              "lessThan": "774394d27930ec4cf4cb3eed8ab6a4d20cb2430a",
              "status": "affected",
              "version": "684b89bc39ce4f204b1a2b180f39f2eb36a6b695",
              "versionType": "git"
            },
            {
              "lessThan": "b1896543ce59c4258625a35cf41e23a9a1f80ea2",
              "status": "affected",
              "version": "684b89bc39ce4f204b1a2b180f39f2eb36a6b695",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/s390/net/ism_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.19"
            },
            {
              "lessThan": "4.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "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": "6.18.45",
                  "versionStartIncluding": "4.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.9",
                  "versionStartIncluding": "4.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "4.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ism: Fix UAF of sba and ieq during ism_dev_exit()\n\nA ism interrupt handler can be active in parallel with ism_dev_exit(),\naccessing freed data structures.\n\nNo new interrupts will be generated after unregister_ieq(). Drain ongoing\ninterrupt handlers by free_irq(), before freeing ism data structures."
        }
      ],
      "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 UAF is opened in ism_dev_exit() during local PCI/driver teardown (ism_remove on module unload, sysfs unbind, or hot-unplug); remote SMC-D peers can raise ISM IRQs but cannot alone reach the freeing path that creates the dangling sba/ieq pointers.\nAC:L - This is a classic UAF race where the attacker controls the IRQ side by sustaining SMC-D move_data/signal_event traffic (or timing rmmod/unbind) while teardown frees sba/ieq before free_irq(); no uncontrollable memory layout or rare config is required on IBM Z ISM deployments.\nPR:N - Privileged teardown opens the window, but the concurrent UAF dereference is performed by ISM IRQ handlers servicing SMC-D traffic from unprivileged local socket users or remote LPAR peers that need no credentials or capabilities on the victim LPAR, only SMC connectivity.\nUI:N - No victim interaction is required beyond normal automated ISM interrupt processing during driver removal; an attacker only needs to keep SMC-D sessions active (or flood them) while the ISM device is torn down during maintenance, module unload, or hot-unplug.\nS:U - Impact is kernel heap/DMA-coherent memory corruption and privilege escalation within the host/LPAR kernel; it does not cross a VM, hypervisor, IOMMU, or other security-authority boundary.\nC:H - ism_handle_irq() and ism_handle_event() read freed PAGE_SIZE sba and ieq DMA buffers (dmb_bits, dmbe_mask, event entries) after dma_free_coherent(), enabling sprayable slab reuse and arbitrary kernel memory disclosure per UAF guidance.\nI:H - The IRQ handler writes to freed sba fields (summary/event bits, dmbe_mask clears) and then calls dibs client handle_irq/handle_event with attacker-influenced SMC state, providing heap grooming and control-flow hijack primitives from the UAF.\nA:H - Concurrent access to freed sba/ieq in hardirq reliably causes kernel oops/panic during ISM teardown on active SMC-D workloads, and UAF guidance treats any ISM interrupt-time use-after-free as high availability impact even before full exploitation."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T05:41:35.158Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/fc3021284050ecb3bba8a7851340cedcb5037928"
        },
        {
          "url": "https://git.kernel.org/stable/c/774394d27930ec4cf4cb3eed8ab6a4d20cb2430a"
        },
        {
          "url": "https://git.kernel.org/stable/c/b1896543ce59c4258625a35cf41e23a9a1f80ea2"
        }
      ],
      "title": "s390/ism: Fix UAF of sba and ieq during ism_dev_exit()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74690",
    "datePublished": "2026-08-22T15:32:54.650Z",
    "dateReserved": "2026-08-15T05:44:03.926Z",
    "dateUpdated": "2026-08-25T05:41:35.158Z",
    "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

GHSA-F2P8-HWVR-FWMQ

CVE-2026-74690 (GCVE-0-2026-74690)

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Sightings

Nomenclature