Vulnerability-Lookup

GHSA-Q6XR-Q445-2XXH

Vulnerability from github – Published: 2026-03-25 12:30 – Updated: 2026-03-25 12:30

Details

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

tracing: Fix WARN_ON in tracing_buffers_mmap_close

When a process forks, the child process copies the parent's VMAs but the user_mapped reference count is not incremented. As a result, when both the parent and child processes exit, tracing_buffers_mmap_close() is called twice. On the second call, user_mapped is already 0, causing the function to return -ENODEV and triggering a WARN_ON.

Normally, this isn't an issue as the memory is mapped with VM_DONTCOPY set. But this is only a hint, and the application can call madvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the application does that, it can trigger this issue on fork.

Fix it by incrementing the user_mapped reference count without re-mapping the pages in the VMA's open callback.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-23380"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-25T11:16:38Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix WARN_ON in tracing_buffers_mmap_close\n\nWhen a process forks, the child process copies the parent\u0027s VMAs but the\nuser_mapped reference count is not incremented. As a result, when both the\nparent and child processes exit, tracing_buffers_mmap_close() is called\ntwice. On the second call, user_mapped is already 0, causing the function to\nreturn -ENODEV and triggering a WARN_ON.\n\nNormally, this isn\u0027t an issue as the memory is mapped with VM_DONTCOPY set.\nBut this is only a hint, and the application can call\nmadvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the\napplication does that, it can trigger this issue on fork.\n\nFix it by incrementing the user_mapped reference count without re-mapping\nthe pages in the VMA\u0027s open callback.",
  "id": "GHSA-q6xr-q445-2xxh",
  "modified": "2026-03-25T12:30:24Z",
  "published": "2026-03-25T12:30:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23380"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/91f3e8d84c89918769e71393f839c9fefadc2580"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cdd96641b64297a2db42676f051362b76280a58b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-23380 (GCVE-0-2026-23380)

Vulnerability from cvelistv5 – Published: 2026-03-25 10:27 – Updated: 2026-03-25 10:27

Title

tracing: Fix WARN_ON in tracing_buffers_mmap_close

Summary

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix WARN_ON in tracing_buffers_mmap_close When a process forks, the child process copies the parent's VMAs but the user_mapped reference count is not incremented. As a result, when both the parent and child processes exit, tracing_buffers_mmap_close() is called twice. On the second call, user_mapped is already 0, causing the function to return -ENODEV and triggering a WARN_ON. Normally, this isn't an issue as the memory is mapped with VM_DONTCOPY set. But this is only a hint, and the application can call madvise(MADVISE_DOFORK) which resets the VM_DONTCOPY flag. When the application does that, it can trigger this issue on fork. Fix it by incrementing the user_mapped reference count without re-mapping the pages in the VMA's open callback.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/91f3e8d84c8991876…
	https://git.kernel.org/stable/c/cdd96641b64297a2d…
	https://git.kernel.org/stable/c/b0f269ba6fefe9e3c…
	https://git.kernel.org/stable/c/e39bb9e02b68942f8…

Impacted products

Vendor

Product

Version

Linux

Affected: cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 , < 91f3e8d84c89918769e71393f839c9fefadc2580 (git)
Affected: cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 , < cdd96641b64297a2db42676f051362b76280a58b (git)
Affected: cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 , < b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0 (git)
Affected: cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 , < e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e (git)

Linux

Affected: 6.10
Unaffected: 0 , < 6.10 (semver)
Unaffected: 6.12.77 , ≤ 6.12.* (semver)
Unaffected: 6.18.17 , ≤ 6.18.* (semver)
Unaffected: 6.19.7 , ≤ 6.19.* (semver)
Unaffected: 7.0-rc3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
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    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/ring_buffer.h",
            "kernel/trace/ring_buffer.c",
            "kernel/trace/trace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "91f3e8d84c89918769e71393f839c9fefadc2580",
              "status": "affected",
              "version": "cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64",
              "versionType": "git"
            },
            {
              "lessThan": "cdd96641b64297a2db42676f051362b76280a58b",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64",
              "versionType": "git"
            }
          ]
        },
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          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/linux/ring_buffer.h",
            "kernel/trace/ring_buffer.c",
            "kernel/trace/trace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.77",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.17",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.77",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                },
                {
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                },
                {
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        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-25T10:27:59.682Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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      "references": [
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          "url": "https://git.kernel.org/stable/c/cdd96641b64297a2db42676f051362b76280a58b"
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          "url": "https://git.kernel.org/stable/c/b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0"
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        {
          "url": "https://git.kernel.org/stable/c/e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23380",
    "datePublished": "2026-03-25T10:27:59.682Z",
    "dateReserved": "2026-01-13T15:37:46.007Z",
    "dateUpdated": "2026-03-25T10:27:59.682Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

GHSA-Q6XR-Q445-2XXH

CVE-2026-23380 (GCVE-0-2026-23380)

Tags

Sightings

Nomenclature