Vulnerability-Lookup

GHSA-FWH4-95HV-8XHF

Vulnerability from github – Published: 2026-06-24 18:32 – Updated: 2026-06-24 18:32

Details

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

bpf: Fix use-after-free in offloaded map/prog info fill

When querying info for an offloaded BPF map or program, bpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns() obtain the network namespace with get_net(dev_net(offmap->netdev)). However, the associated netdev's netns may be racing with teardown during netns destruction. If the netns refcount has already reached 0, get_net() performs a refcount_t increment on 0, triggering:

refcount_t: addition on 0; use-after-free.

Although rtnl_lock and bpf_devs_lock ensure the netdev pointer remains valid, they cannot prevent the netns refcount from reaching zero.

Fix this by using maybe_get_net() instead of get_net(). maybe_get_net() uses refcount_inc_not_zero() and returns NULL if the refcount is already zero, which causes ns_get_path_cb() to fail and the caller to return -ENOENT -- the correct behavior when the netns is being destroyed.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-53089"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-24T17:17:23Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix use-after-free in offloaded map/prog info fill\n\nWhen querying info for an offloaded BPF map or program,\nbpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns()\nobtain the network namespace with get_net(dev_net(offmap-\u003enetdev)).\nHowever, the associated netdev\u0027s netns may be racing with teardown\nduring netns destruction. If the netns refcount has already reached 0,\nget_net() performs a refcount_t increment on 0, triggering:\n\n  refcount_t: addition on 0; use-after-free.\n\nAlthough rtnl_lock and bpf_devs_lock ensure the netdev pointer remains\nvalid, they cannot prevent the netns refcount from reaching zero.\n\nFix this by using maybe_get_net() instead of get_net(). maybe_get_net()\nuses refcount_inc_not_zero() and returns NULL if the refcount is already\nzero, which causes ns_get_path_cb() to fail and the caller to return\n-ENOENT -- the correct behavior when the netns is being destroyed.",
  "id": "GHSA-fwh4-95hv-8xhf",
  "modified": "2026-06-24T18:32:46Z",
  "published": "2026-06-24T18:32:46Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53089"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a0c584fc18056709c8e047a82a6045d6c209f4ce"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a51e7fbe94a87e236631a83973d4f558310b2cd2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-53089 (GCVE-0-2026-53089)

Vulnerability from cvelistv5 – Published: 2026-06-24 16:30 – Updated: 2026-06-24 16:30

Title

bpf: Fix use-after-free in offloaded map/prog info fill

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix use-after-free in offloaded map/prog info fill When querying info for an offloaded BPF map or program, bpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns() obtain the network namespace with get_net(dev_net(offmap->netdev)). However, the associated netdev's netns may be racing with teardown during netns destruction. If the netns refcount has already reached 0, get_net() performs a refcount_t increment on 0, triggering: refcount_t: addition on 0; use-after-free. Although rtnl_lock and bpf_devs_lock ensure the netdev pointer remains valid, they cannot prevent the netns refcount from reaching zero. Fix this by using maybe_get_net() instead of get_net(). maybe_get_net() uses refcount_inc_not_zero() and returns NULL if the refcount is already zero, which causes ns_get_path_cb() to fail and the caller to return -ENOENT -- the correct behavior when the netns is being destroyed.

Severity

No CVSS data available.

Assigner

Linux

References

2 references

URL	Tags
https://git.kernel.org/stable/c/a51e7fbe94a87e236…
https://git.kernel.org/stable/c/a0c584fc18056709c…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 675fc275a3a2d905535207237402c6d8dcb5fa4b , < a51e7fbe94a87e236631a83973d4f558310b2cd2 (git) Affected: 675fc275a3a2d905535207237402c6d8dcb5fa4b , < a0c584fc18056709c8e047a82a6045d6c209f4ce (git)
Linux	Linux	Affected: 4.16 Unaffected: 0 , < 4.16 (semver) Unaffected: 7.0.10 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/offload.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a51e7fbe94a87e236631a83973d4f558310b2cd2",
              "status": "affected",
              "version": "675fc275a3a2d905535207237402c6d8dcb5fa4b",
              "versionType": "git"
            },
            {
              "lessThan": "a0c584fc18056709c8e047a82a6045d6c209f4ce",
              "status": "affected",
              "version": "675fc275a3a2d905535207237402c6d8dcb5fa4b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/offload.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.16"
            },
            {
              "lessThan": "4.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.10",
                  "versionStartIncluding": "4.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "4.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix use-after-free in offloaded map/prog info fill\n\nWhen querying info for an offloaded BPF map or program,\nbpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns()\nobtain the network namespace with get_net(dev_net(offmap-\u003enetdev)).\nHowever, the associated netdev\u0027s netns may be racing with teardown\nduring netns destruction. If the netns refcount has already reached 0,\nget_net() performs a refcount_t increment on 0, triggering:\n\n  refcount_t: addition on 0; use-after-free.\n\nAlthough rtnl_lock and bpf_devs_lock ensure the netdev pointer remains\nvalid, they cannot prevent the netns refcount from reaching zero.\n\nFix this by using maybe_get_net() instead of get_net(). maybe_get_net()\nuses refcount_inc_not_zero() and returns NULL if the refcount is already\nzero, which causes ns_get_path_cb() to fail and the caller to return\n-ENOENT -- the correct behavior when the netns is being destroyed."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-24T16:30:28.531Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/a51e7fbe94a87e236631a83973d4f558310b2cd2"
        },
        {
          "url": "https://git.kernel.org/stable/c/a0c584fc18056709c8e047a82a6045d6c209f4ce"
        }
      ],
      "title": "bpf: Fix use-after-free in offloaded map/prog info fill",
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-53089",
    "datePublished": "2026-06-24T16:30:28.531Z",
    "dateReserved": "2026-06-09T07:44:35.384Z",
    "dateUpdated": "2026-06-24T16:30:28.531Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-FWH4-95HV-8XHF

CVE-2026-53089 (GCVE-0-2026-53089)

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Sightings

Nomenclature