Vulnerability-Lookup

GHSA-Q3RX-6VFG-RC7W

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-19 18:31

Details

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

fprobe: Fix unregister_fprobe() to wait for RCU grace period

Commit 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer") changed fprobe to register struct fprobe to an rcu-hlist, but it forgot to wait for RCU GP. Thus there can be use-after-free if the fprobe is released right after unregistering. This can be happened on fprobe event and sample module code.

To fix this issue, add synchronize_rcu() in unregister_fprobe().

Note that BPF is OK because fprobe is used as a part of bpf_kprobe_multi_link. This unregisters its fprobe in bpf_kprobe_multi_link_release() and it is deallocated via bpf_kprobe_multi_link_dealloc(), which is invoked from bpf_link_defer_dealloc_rcu_gp() RCU callback.

For BPF, this also introduced unregister_fprobe_async() which does NOT wait for RCU grace priod.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64075"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:48Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfprobe: Fix unregister_fprobe() to wait for RCU grace period\n\nCommit 4346ba1604093 (\"fprobe: Rewrite fprobe on function-graph tracer\")\nchanged fprobe to register struct fprobe to an rcu-hlist, but it forgot\nto wait for RCU GP. Thus there can be use-after-free if the fprobe is\nreleased right after unregistering. This can be happened on fprobe\nevent and sample module code.\n\nTo fix this issue, add synchronize_rcu() in unregister_fprobe().\n\nNote that BPF is OK because fprobe is used as a part of\nbpf_kprobe_multi_link. This unregisters its fprobe in\nbpf_kprobe_multi_link_release() and it is deallocated via\nbpf_kprobe_multi_link_dealloc(), which is invoked from\nbpf_link_defer_dealloc_rcu_gp() RCU callback.\n\nFor BPF, this also introduced unregister_fprobe_async() which does\nNOT wait for RCU grace priod.",
  "id": "GHSA-q3rx-6vfg-rc7w",
  "modified": "2026-07-19T18:31:51Z",
  "published": "2026-07-19T18:31:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64075"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/56b4cfcf1518245493c60fd39c56978f508f1816"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/657b594b2084b39a4bc6d8493aa2140cb00cea49"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a4f6a9005ed6cfd360ef2520430927f05f92ffb0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-64075 (GCVE-0-2026-64075)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-19 15:39

Title

fprobe: Fix unregister_fprobe() to wait for RCU grace period

Summary

In the Linux kernel, the following vulnerability has been resolved: fprobe: Fix unregister_fprobe() to wait for RCU grace period Commit 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer") changed fprobe to register struct fprobe to an rcu-hlist, but it forgot to wait for RCU GP. Thus there can be use-after-free if the fprobe is released right after unregistering. This can be happened on fprobe event and sample module code. To fix this issue, add synchronize_rcu() in unregister_fprobe(). Note that BPF is OK because fprobe is used as a part of bpf_kprobe_multi_link. This unregisters its fprobe in bpf_kprobe_multi_link_release() and it is deallocated via bpf_kprobe_multi_link_dealloc(), which is invoked from bpf_link_defer_dealloc_rcu_gp() RCU callback. For BPF, this also introduced unregister_fprobe_async() which does NOT wait for RCU grace priod.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/56b4cfcf151824549…
https://git.kernel.org/stable/c/a4f6a9005ed6cfd36…
https://git.kernel.org/stable/c/657b594b2084b39a4…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4346ba1604093305a287e08eb465a9c15ba05b80 , < 56b4cfcf1518245493c60fd39c56978f508f1816 (git) Affected: 4346ba1604093305a287e08eb465a9c15ba05b80 , < a4f6a9005ed6cfd360ef2520430927f05f92ffb0 (git) Affected: 4346ba1604093305a287e08eb465a9c15ba05b80 , < 657b594b2084b39a4bc6d8493aa2140cb00cea49 (git)
Linux	Linux	Affected: 6.14 Unaffected: 0 , < 6.14 (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/fprobe.h",
            "kernel/trace/bpf_trace.c",
            "kernel/trace/fprobe.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "56b4cfcf1518245493c60fd39c56978f508f1816",
              "status": "affected",
              "version": "4346ba1604093305a287e08eb465a9c15ba05b80",
              "versionType": "git"
            },
            {
              "lessThan": "a4f6a9005ed6cfd360ef2520430927f05f92ffb0",
              "status": "affected",
              "version": "4346ba1604093305a287e08eb465a9c15ba05b80",
              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            }
          ]
        },
        {
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          ],
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
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        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
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                }
              ],
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              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfprobe: Fix unregister_fprobe() to wait for RCU grace period\n\nCommit 4346ba1604093 (\"fprobe: Rewrite fprobe on function-graph tracer\")\nchanged fprobe to register struct fprobe to an rcu-hlist, but it forgot\nto wait for RCU GP. Thus there can be use-after-free if the fprobe is\nreleased right after unregistering. This can be happened on fprobe\nevent and sample module code.\n\nTo fix this issue, add synchronize_rcu() in unregister_fprobe().\n\nNote that BPF is OK because fprobe is used as a part of\nbpf_kprobe_multi_link. This unregisters its fprobe in\nbpf_kprobe_multi_link_release() and it is deallocated via\nbpf_kprobe_multi_link_dealloc(), which is invoked from\nbpf_link_defer_dealloc_rcu_gp() RCU callback.\n\nFor BPF, this also introduced unregister_fprobe_async() which does\nNOT wait for RCU grace priod."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-19T15:39:49.679Z",
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        },
        {
          "url": "https://git.kernel.org/stable/c/657b594b2084b39a4bc6d8493aa2140cb00cea49"
        }
      ],
      "title": "fprobe: Fix unregister_fprobe() to wait for RCU grace period",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64075",
    "datePublished": "2026-07-19T15:39:49.679Z",
    "dateReserved": "2026-07-19T07:54:57.031Z",
    "dateUpdated": "2026-07-19T15:39:49.679Z",
    "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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-Q3RX-6VFG-RC7W

CVE-2026-64075 (GCVE-0-2026-64075)

Tags

Sightings

Nomenclature