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GHSA-V8V9-CP6P-QM5R

Vulnerability from github – Published: 2026-10-14 15:32 – Updated: 2026-10-14 15:32

Details

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

s390/ipl: Fix NULL deref in kdump without re-IPL parm block

Some IPL types, like HMC FTP boot or QEMU direct kernel boot, might not provide an IPL parameter block. In this case, reipl_type_init() selects IPL_TYPE_UNKNOWN, and reipl_block_actual remains NULL.

kdump passes the re-IPL parameter block to the dump kernel through os_info. Before commit 3b9678472bab ("s390/ipl: correct kdump reipl block checksum calculation"), the os_info entry was added only for IPL types which initialized reipl_block_actual. That commit moved the os_info update to machine_crash_shutdown(), making it unconditional. As a result, set_os_info_reipl_block() dereferences reipl_block_actual for IPL_TYPE_UNKNOWN. This may happen to work by chance when address zero contains readable lowcore data and the resulting empty os_info entry is ignored by the dump kernel.

Skip the os_info update when no re-IPL parameter block is available. Kdump then collect the dump and reboot without setting re-IPL parameter block.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-98400"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-14T14:17:51Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ipl: Fix NULL deref in kdump without re-IPL parm block\n\nSome IPL types, like HMC FTP boot or QEMU direct kernel boot, might\nnot provide an IPL parameter block. In this case, reipl_type_init()\nselects IPL_TYPE_UNKNOWN, and reipl_block_actual remains NULL.\n\nkdump passes the re-IPL parameter block to the dump kernel through\nos_info. Before commit 3b9678472bab (\"s390/ipl: correct kdump reipl\nblock checksum calculation\"), the os_info entry was added only for\nIPL types which initialized reipl_block_actual. That commit moved the\nos_info update to machine_crash_shutdown(), making it unconditional. As\na result, set_os_info_reipl_block() dereferences reipl_block_actual for\nIPL_TYPE_UNKNOWN. This may happen to work by chance when address zero\ncontains readable lowcore data and the resulting empty os_info entry is\nignored by the dump kernel.\n\nSkip the os_info update when no re-IPL parameter block is available.\nKdump then collect the dump and reboot without setting re-IPL parameter\nblock.",
  "id": "GHSA-v8v9-cp6p-qm5r",
  "modified": "2026-10-14T15:32:19Z",
  "published": "2026-10-14T15:32:19Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98400"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/030e88812435fc5d6aa42eee41fa77b5ea620327"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/50f9c40768e84f30d374235b3ee3850a94d9ac29"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7f918871112e8e7c581e99eb8e545af4e59c8367"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/92d0829eae257544b6b0faccb6e7079c45e22d48"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-98400 (GCVE-0-2026-98400)

Vulnerability from cvelistv5 – Published: 2026-10-14 13:26 – Updated: 2026-10-19 09:18

Title

s390/ipl: Fix NULL deref in kdump without re-IPL parm block

Summary

In the Linux kernel, the following vulnerability has been resolved: s390/ipl: Fix NULL deref in kdump without re-IPL parm block Some IPL types, like HMC FTP boot or QEMU direct kernel boot, might not provide an IPL parameter block. In this case, reipl_type_init() selects IPL_TYPE_UNKNOWN, and reipl_block_actual remains NULL. kdump passes the re-IPL parameter block to the dump kernel through os_info. Before commit 3b9678472bab ("s390/ipl: correct kdump reipl block checksum calculation"), the os_info entry was added only for IPL types which initialized reipl_block_actual. That commit moved the os_info update to machine_crash_shutdown(), making it unconditional. As a result, set_os_info_reipl_block() dereferences reipl_block_actual for IPL_TYPE_UNKNOWN. This may happen to work by chance when address zero contains readable lowcore data and the resulting empty os_info entry is ignored by the dump kernel. Skip the os_info update when no re-IPL parameter block is available. Kdump then collect the dump and reboot without setting re-IPL parameter block.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7056 records in the last 180 days details

References

5 references

URL	Tags
https://git.kernel.org/stable/c/030e88812435fc5d6…
https://git.kernel.org/stable/c/92d0829eae257544b…
https://git.kernel.org/stable/c/50f9c40768e84f30d…
https://git.kernel.org/stable/c/b6bf82bc5e00afaf8…
https://git.kernel.org/stable/c/7f918871112e8e7c5…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3b9678472bab86ae654cf2c18d5dd551558045be , < 030e88812435fc5d6aa42eee41fa77b5ea620327 (git) Affected: 3b9678472bab86ae654cf2c18d5dd551558045be , < 92d0829eae257544b6b0faccb6e7079c45e22d48 (git) Affected: 3b9678472bab86ae654cf2c18d5dd551558045be , < 50f9c40768e84f30d374235b3ee3850a94d9ac29 (git) Affected: 3b9678472bab86ae654cf2c18d5dd551558045be , < b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd (git) Affected: 3b9678472bab86ae654cf2c18d5dd551558045be , < 7f918871112e8e7c581e99eb8e545af4e59c8367 (git)
Linux	Linux	Affected: 4.17 Unaffected: 0 , < 4.17 (semver) Unaffected: 6.6.158 , ≤ 6.6.* (semver) Unaffected: 6.12.111 , ≤ 6.12.* (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2.7 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/s390/kernel/ipl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "3b9678472bab86ae654cf2c18d5dd551558045be",
              "versionType": "git"
            },
            {
              "lessThan": "92d0829eae257544b6b0faccb6e7079c45e22d48",
              "status": "affected",
              "version": "3b9678472bab86ae654cf2c18d5dd551558045be",
              "versionType": "git"
            },
            {
              "lessThan": "50f9c40768e84f30d374235b3ee3850a94d9ac29",
              "status": "affected",
              "version": "3b9678472bab86ae654cf2c18d5dd551558045be",
              "versionType": "git"
            },
            {
              "lessThan": "b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd",
              "status": "affected",
              "version": "3b9678472bab86ae654cf2c18d5dd551558045be",
              "versionType": "git"
            },
            {
              "lessThan": "7f918871112e8e7c581e99eb8e545af4e59c8367",
              "status": "affected",
              "version": "3b9678472bab86ae654cf2c18d5dd551558045be",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/s390/kernel/ipl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.17"
            },
            {
              "lessThan": "4.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.158",
                  "versionStartIncluding": "4.17",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                }
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              "negate": false,
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ipl: Fix NULL deref in kdump without re-IPL parm block\n\nSome IPL types, like HMC FTP boot or QEMU direct kernel boot, might\nnot provide an IPL parameter block. In this case, reipl_type_init()\nselects IPL_TYPE_UNKNOWN, and reipl_block_actual remains NULL.\n\nkdump passes the re-IPL parameter block to the dump kernel through\nos_info. Before commit 3b9678472bab (\"s390/ipl: correct kdump reipl\nblock checksum calculation\"), the os_info entry was added only for\nIPL types which initialized reipl_block_actual. That commit moved the\nos_info update to machine_crash_shutdown(), making it unconditional. As\na result, set_os_info_reipl_block() dereferences reipl_block_actual for\nIPL_TYPE_UNKNOWN. This may happen to work by chance when address zero\ncontains readable lowcore data and the resulting empty os_info entry is\nignored by the dump kernel.\n\nSkip the os_info update when no re-IPL parameter block is available.\nKdump then collect the dump and reboot without setting re-IPL parameter\nblock."
        }
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        "dateUpdated": "2026-10-19T09:18:53.762Z",
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        {
          "url": "https://git.kernel.org/stable/c/7f918871112e8e7c581e99eb8e545af4e59c8367"
        }
      ],
      "title": "s390/ipl: Fix NULL deref in kdump without re-IPL parm block",
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    "cveId": "CVE-2026-98400",
    "datePublished": "2026-10-14T13:26:00.872Z",
    "dateReserved": "2026-09-25T10:25:14.346Z",
    "dateUpdated": "2026-10-19T09:18:53.762Z",
    "state": "PUBLISHED"
  },
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  "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.

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