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GHSA-HJW3-FXM2-VPH2

Vulnerability from github – Published: 2026-09-17 18:31 – Updated: 2026-09-18 18:31

Details

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

module/dups: Fix use-after-free in kmod_dup_req lifetime handling

The kmod dups code uses RCU to ensure that a kmod_dup_req instance is freed only after it is no longer referenced. When releasing an instance, the kmod_dup_request_delete() function removes the kmod_dup_req from the dup_kmod_reqs list, waits via synchronize_rcu() and finally frees it. However, this doesn't work correctly because parallel users referencing the instance in kmod_dup_request_exists_wait() don't enter an RCU read-side critical section. This can result in a use-after-free.

The kmod_dup_request_exists_wait() function may need to hold a valid reference to a kmod_dup_req instance across a blocking wait until the corresponding modprobe command completes. This makes it unsuitable for RCU.

Fix the issue by changing the lifecycle management of kmod_dup_req to use reference counting.

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-2026-90291"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-17T17:17:26Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmodule/dups: Fix use-after-free in kmod_dup_req lifetime handling\n\nThe kmod dups code uses RCU to ensure that a kmod_dup_req instance is freed\nonly after it is no longer referenced. When releasing an instance, the\nkmod_dup_request_delete() function removes the kmod_dup_req from the\ndup_kmod_reqs list, waits via synchronize_rcu() and finally frees it.\nHowever, this doesn\u0027t work correctly because parallel users referencing the\ninstance in kmod_dup_request_exists_wait() don\u0027t enter an RCU read-side\ncritical section. This can result in a use-after-free.\n\nThe kmod_dup_request_exists_wait() function may need to hold a valid\nreference to a kmod_dup_req instance across a blocking wait until the\ncorresponding modprobe command completes. This makes it unsuitable for RCU.\n\nFix the issue by changing the lifecycle management of kmod_dup_req to use\nreference counting.",
  "id": "GHSA-hjw3-fxm2-vph2",
  "modified": "2026-09-18T18:31:29Z",
  "published": "2026-09-17T18:31:59Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90291"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c85e0fb528e039aa8ea1e9c2a1f64347f990541"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5eecb11b543f9f417bcf0dea239ff99c6af65dbd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b2709aad7599f6fd957939b60f4a8323c8f08072"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd2396fc9684d2cfd3f3c3f09c79d6d9d725b0ca"
    }
  ],
  "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-2026-90291 (GCVE-0-2026-90291)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:08 – Updated: 2026-09-18 17:54

Title

module/dups: Fix use-after-free in kmod_dup_req lifetime handling

Summary

In the Linux kernel, the following vulnerability has been resolved: module/dups: Fix use-after-free in kmod_dup_req lifetime handling The kmod dups code uses RCU to ensure that a kmod_dup_req instance is freed only after it is no longer referenced. When releasing an instance, the kmod_dup_request_delete() function removes the kmod_dup_req from the dup_kmod_reqs list, waits via synchronize_rcu() and finally frees it. However, this doesn't work correctly because parallel users referencing the instance in kmod_dup_request_exists_wait() don't enter an RCU read-side critical section. This can result in a use-after-free. The kmod_dup_request_exists_wait() function may need to hold a valid reference to a kmod_dup_req instance across a blocking wait until the corresponding modprobe command completes. This makes it unsuitable for RCU. Fix the issue by changing the lifecycle management of kmod_dup_req to use reference counting.

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 mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/2c85e0fb528e039aa…
https://git.kernel.org/stable/c/b2709aad7599f6fd9…
https://git.kernel.org/stable/c/cd2396fc9684d2cfd…
https://git.kernel.org/stable/c/5eecb11b543f9f417…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8660484ed1cf3261e89e0bad94c6395597e87599 , < 2c85e0fb528e039aa8ea1e9c2a1f64347f990541 (git) Affected: 8660484ed1cf3261e89e0bad94c6395597e87599 , < b2709aad7599f6fd957939b60f4a8323c8f08072 (git) Affected: 8660484ed1cf3261e89e0bad94c6395597e87599 , < cd2396fc9684d2cfd3f3c3f09c79d6d9d725b0ca (git) Affected: 8660484ed1cf3261e89e0bad94c6395597e87599 , < 5eecb11b543f9f417bcf0dea239ff99c6af65dbd (git)
Linux	Linux	Affected: 6.4 Unaffected: 0 , < 6.4 (semver) Unaffected: 6.12.110 , ≤ 6.12.* (semver) Unaffected: 6.18.52 , ≤ 6.18.* (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/module/dups.c"
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          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2c85e0fb528e039aa8ea1e9c2a1f64347f990541",
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              "versionType": "git"
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            },
            {
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              "versionType": "git"
            },
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              "versionType": "git"
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            "kernel/module/dups.c"
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.4"
            },
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              "status": "unaffected",
              "version": "0",
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            },
            {
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              "status": "unaffected",
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            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
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            {
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              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
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              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
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        }
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        {
          "nodes": [
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                  "versionEndExcluding": "6.12.110",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.52",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                }
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmodule/dups: Fix use-after-free in kmod_dup_req lifetime handling\n\nThe kmod dups code uses RCU to ensure that a kmod_dup_req instance is freed\nonly after it is no longer referenced. When releasing an instance, the\nkmod_dup_request_delete() function removes the kmod_dup_req from the\ndup_kmod_reqs list, waits via synchronize_rcu() and finally frees it.\nHowever, this doesn\u0027t work correctly because parallel users referencing the\ninstance in kmod_dup_request_exists_wait() don\u0027t enter an RCU read-side\ncritical section. This can result in a use-after-free.\n\nThe kmod_dup_request_exists_wait() function may need to hold a valid\nreference to a kmod_dup_req instance across a blocking wait until the\ncorresponding modprobe command completes. This makes it unsuitable for RCU.\n\nFix the issue by changing the lifecycle management of kmod_dup_req to use\nreference counting."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "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 - The UAF is in kmod_dup_request_exists_wait(), reached from __request_module() when tracking a duplicate autoload. An unprivileged process hits that via socket(2) \u2192 __sys_socket() \u2192 __sock_create(), which calls request_module(\"net-pf-%d\") for an unloaded protocol family; the trigger is that local syscall, not a remote protocol message.\nAC:L - The attacker drives both sides: one socket() call\u0027s request_module() inserts a kmod_dup_req and kmod_dup_request_announce() queues kmod_dup_request_delete() for 60*HZ, then further socket() calls look up that entry, drop kmod_dup_mutex, and wait_for_completion_state() on first_req_done without rcu_read_lock, racing the delayed kfree.\nPR:L - __request_module() has no capable() check; it only calls security_kernel_module_request(), whose default LSM hook returns 0. __sock_create()\u0027s request_module(\"net-pf-%d\") path has no capability gate either, so a normal unprivileged local user can trigger the duplicate-autoload race.\nUI:N - The attacker issues their own socket() syscalls to force concurrent request_module() calls for the same net-pf-%d name; no other user must mount a filesystem, open a file, or otherwise cooperate.\nS:U - The use-after-free is of a kmalloc\u0027d kmod_dup_req in kernel/module/dups.c and corrupts host kernel heap. That is a standard in-kernel privilege-escalation impact inside one security authority, not a VM or IOMMU boundary crossing.\nC:H - After kmod_dup_request_delete() kfree()s the kmod_dup_req, a racing kmod_dup_request_exists_wait() still reads kmod_req-\u003edup_ret and takes first_req_done.wait.lock inside wait_for_common(). Reclaiming that slab lets the attacker control those contents, a UAF read primitive.\nI:H - wait_for_common() takes first_req_done.wait.lock and can __prepare_to_swait() onto the completion wait queue in the already-freed kmod_dup_req. Heap spraying that object yields an attacker-controlled wait-queue/list write, a UAF write and control-flow hijack primitive.\nA:H - Using a freed kmod_dup_req\u0027s completion spinlock in wait_for_common(), or kfree() racing wait_for_completion_state(\u0026kmod_req-\u003efirst_req_done), oopses or panics the kernel even without a full exploit."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T17:54:20.524Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
          "url": "https://git.kernel.org/stable/c/5eecb11b543f9f417bcf0dea239ff99c6af65dbd"
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    "cveId": "CVE-2026-90291",
    "datePublished": "2026-09-17T16:08:18.700Z",
    "dateReserved": "2026-09-11T19:38:34.798Z",
    "dateUpdated": "2026-09-18T17:54:20.524Z",
    "state": "PUBLISHED"
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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.
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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.
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GHSA-HJW3-FXM2-VPH2

CVE-2026-90291 (GCVE-0-2026-90291)

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