Vulnerability-Lookup

GHSA-H63H-WCX8-JM4R

Vulnerability from github – Published: 2026-09-16 12:30 – Updated: 2026-09-16 15:31

Details

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

mm/page_alloc: don't spin_trylock() in NMI on UP

Patch series "mm/page_alloc: fixes for free_pages_nolock() on RT/UP".

Pre-existing bugs found by Sashiko during review of this other series: https://lore.kernel.org/all/20260703-alloc-trylock-v5-0-c87b714e19d3@google.com/

I have not reproduced these bugs, and I suspect there is no real-world user that is affected by them.

This patch (of 2):

As noted in can_spin_trylock(), using this is unsafe in this context. commit 620b46ed6ae17 ("mm/page_alloc: return NULL early from alloc_frozen_pages_nolock() in NMI on UP") fixed this on the alloc side but missed the free side.

Impact: If BPF programs using these features in NMI (probably tracing) are present on non-SMP builds this might crash the kernel and is probably exploitable by local attackers for privilege escalation.

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-90046"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T11:17:17Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_alloc: don\u0027t spin_trylock() in NMI on UP\n\nPatch series \"mm/page_alloc: fixes for free_pages_nolock() on RT/UP\".\n\nPre-existing bugs found by Sashiko during review of this other series:\nhttps://lore.kernel.org/all/20260703-alloc-trylock-v5-0-c87b714e19d3@google.com/\n\nI have not reproduced these bugs, and I suspect there is no real-world\nuser that is affected by them.\n\n\nThis patch (of 2):\n\nAs noted in can_spin_trylock(), using this is unsafe in this context. \ncommit 620b46ed6ae17 (\"mm/page_alloc: return NULL early from\nalloc_frozen_pages_nolock() in NMI on UP\") fixed this on the alloc side\nbut missed the free side.\n\nImpact: If BPF programs using these features in NMI (probably tracing) are\npresent on non-SMP builds this might crash the kernel and is probably\nexploitable by local attackers for privilege escalation.",
  "id": "GHSA-h63h-wcx8-jm4r",
  "modified": "2026-09-16T15:31:08Z",
  "published": "2026-09-16T12:30:46Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90046"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/06c76d3c389ff504052f64b1acee44651bd847fa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3105ae628fb785d48b49256468be4f21a7b3cfc0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/68a069b407303e71db371df85036101e8ff59280"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-90046 (GCVE-0-2026-90046)

Vulnerability from cvelistv5 – Published: 2026-09-16 10:33 – Updated: 2026-10-19 08:57

Title

mm/page_alloc: don't spin_trylock() in NMI on UP

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/page_alloc: don't spin_trylock() in NMI on UP Patch series "mm/page_alloc: fixes for free_pages_nolock() on RT/UP". Pre-existing bugs found by Sashiko during review of this other series: https://lore.kernel.org/all/20260703-alloc-trylock-v5-0-c87b714e19d3@google.com/ I have not reproduced these bugs, and I suspect there is no real-world user that is affected by them. This patch (of 2): As noted in can_spin_trylock(), using this is unsafe in this context. commit 620b46ed6ae17 ("mm/page_alloc: return NULL early from alloc_frozen_pages_nolock() in NMI on UP") fixed this on the alloc side but missed the free side. Impact: If BPF programs using these features in NMI (probably tracing) are present on non-SMP builds this might crash the kernel and is probably exploitable by local attackers for privilege escalation.

Severity

7.8 (High)


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

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6639 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/06c76d3c389ff5040…
https://git.kernel.org/stable/c/68a069b407303e71d…
https://git.kernel.org/stable/c/3105ae628fb785d48…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8c57b687e8331eb80e302a2c528b18b966a9ac7a , < 06c76d3c389ff504052f64b1acee44651bd847fa (git) Affected: 8c57b687e8331eb80e302a2c528b18b966a9ac7a , < 68a069b407303e71db371df85036101e8ff59280 (git) Affected: 8c57b687e8331eb80e302a2c528b18b966a9ac7a , < 3105ae628fb785d48b49256468be4f21a7b3cfc0 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.51 , ≤ 6.18.* (semver) Unaffected: 7.2.5 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "mm/page_alloc.c"
          ],
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          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "06c76d3c389ff504052f64b1acee44651bd847fa",
              "status": "affected",
              "version": "8c57b687e8331eb80e302a2c528b18b966a9ac7a",
              "versionType": "git"
            },
            {
              "lessThan": "68a069b407303e71db371df85036101e8ff59280",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            }
          ]
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        {
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            "mm/page_alloc.c"
          ],
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          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "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": "6.18.51",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_alloc: don\u0027t spin_trylock() in NMI on UP\n\nPatch series \"mm/page_alloc: fixes for free_pages_nolock() on RT/UP\".\n\nPre-existing bugs found by Sashiko during review of this other series:\nhttps://lore.kernel.org/all/20260703-alloc-trylock-v5-0-c87b714e19d3@google.com/\n\nI have not reproduced these bugs, and I suspect there is no real-world\nuser that is affected by them.\n\n\nThis patch (of 2):\n\nAs noted in can_spin_trylock(), using this is unsafe in this context. \ncommit 620b46ed6ae17 (\"mm/page_alloc: return NULL early from\nalloc_frozen_pages_nolock() in NMI on UP\") fixed this on the alloc side\nbut missed the free side.\n\nImpact: If BPF programs using these features in NMI (probably tracing) are\npresent on non-SMP builds this might crash the kernel and is probably\nexploitable by local attackers for privilege escalation."
        }
      ],
      "metrics": [
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            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - free_pages_nolock is reached from local BPF programs (arena/bpf_map_alloc_pages and related nolock helpers) running in NMI, typically a BPF_PROG_TYPE_PERF_EVENT overflow handler installed via bpf()/perf_event_open. It is not reachable from unauthenticated network packets or in-kernel servers such as ksmbd/nfsd.\nAC:L - Scoring assumes a uniprocessor (!CONFIG_SMP) kernel, a reasonable embedded/IoT deployment. An attacker who can attach a BPF perf-event program controls the NMI that calls free_pages_nolock and can concurrently run page-allocator work so the NMI interrupts zone-\u003elock; the in-tree slub_kunit NMI overflow test shows this reentry is reliably triggerable.\nPR:L - Loading the NMI BPF program requires CAP_BPF and CAP_PERFMON, which are sub-root capabilities. BPF tokens can delegate those checks into a non-init user namespace in plausible container/tracing deployments, so this is treated as low privileges rather than init-namespace root.\nUI:N - The attacker loads the BPF program, programs the PMU, and drives local memory activity themselves. No separate victim action such as mounting a filesystem or opening a crafted file is required.\nS:U - Re-entrant buddy/zone-lock corruption stays inside the kernel\u0027s own security authority and yields local privilege escalation, not a VM, IOMMU, or other cross-boundary escape.\nC:H - Nested spin_trylock of zone-\u003elock on UP lets the NMI mutate buddy freelists while the interrupted context is mid-update, corrupting page-allocator metadata. That overlapping-page primitive can be leveraged for arbitrary kernel memory disclosure.\nI:H - The same freelist corruption is a well-known arbitrary-write and control-flow hijack primitive, and the fix commit states the bug is probably exploitable by local attackers for privilege escalation.\nA:H - Re-entrant zone-lock and buddy updates crash the kernel via oops, panic, or a DEBUG_SPINLOCK BUG on UP, which is a full availability loss."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:57:04.231Z",
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          "url": "https://git.kernel.org/stable/c/06c76d3c389ff504052f64b1acee44651bd847fa"
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        {
          "url": "https://git.kernel.org/stable/c/68a069b407303e71db371df85036101e8ff59280"
        },
        {
          "url": "https://git.kernel.org/stable/c/3105ae628fb785d48b49256468be4f21a7b3cfc0"
        }
      ],
      "title": "mm/page_alloc: don\u0027t spin_trylock() in NMI on UP",
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        "engine": "bippy-1.2.0"
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90046",
    "datePublished": "2026-09-16T10:33:43.156Z",
    "dateReserved": "2026-09-11T19:38:34.783Z",
    "dateUpdated": "2026-10-19T08:57:04.231Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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.

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