GHSA-238F-H9Q7-HG73
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-15 06:32In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_ct: fix nf_connlabels leak on two error paths
tcf_ct_fill_params() calls nf_connlabels_get() (setting put_labels) when TCA_CT_LABELS is present, but two later error sites use a bare return instead of "goto err", skipping the err: nf_connlabels_put() cleanup. They also precede the "p->put_labels = put_labels" assignment, so the tcf_ct_params_free() fallback does not release the count either. Each failed RTM_NEWACTION on these paths leaks one nf_connlabels reference: net->ct.labels_used is incremented and never released. The action is reachable with CAP_NET_ADMIN over the netns, i.e. from an unprivileged user namespace on default-userns kernels.
Impact: an unprivileged user with CAP_NET_ADMIN over a network namespace (e.g. via user namespaces) leaks one nf_connlabels reference per failed RTM_NEWACTION on the two error paths; net->ct.labels_used is never released.
The err: label is safe to reach from both sites: p->tmpl is still NULL there (kzalloc'd, not yet assigned) and nf_ct_put(NULL) is a no-op, so no inline release is needed.
{
"affected": [],
"aliases": [
"CVE-2026-72430"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:16Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ct: fix nf_connlabels leak on two error paths\n\ntcf_ct_fill_params() calls nf_connlabels_get() (setting put_labels) when\nTCA_CT_LABELS is present, but two later error sites use a bare return\ninstead of \"goto err\", skipping the err: nf_connlabels_put() cleanup.\nThey also precede the \"p-\u003eput_labels = put_labels\" assignment, so the\ntcf_ct_params_free() fallback does not release the count either. Each\nfailed RTM_NEWACTION on these paths leaks one nf_connlabels reference:\nnet-\u003ect.labels_used is incremented and never released. The action is\nreachable with CAP_NET_ADMIN over the netns, i.e. from an unprivileged\nuser namespace on default-userns kernels.\n\nImpact: an unprivileged user with CAP_NET_ADMIN over a network namespace\n(e.g. via user namespaces) leaks one nf_connlabels reference per failed\nRTM_NEWACTION on the two error paths; net-\u003ect.labels_used is never\nreleased.\n\nThe err: label is safe to reach from both sites: p-\u003etmpl is still NULL\nthere (kzalloc\u0027d, not yet assigned) and nf_ct_put(NULL) is a no-op, so\nno inline release is needed.",
"id": "GHSA-238f-h9q7-hg73",
"modified": "2026-08-15T06:32:24Z",
"published": "2026-08-15T06:32:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72430"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0c3d8fc87e10e38fe054ece009d6d1f66bef2cd4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/13b561c893c741635adce3781490a7a1099106c8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/16e088016f38cf728a0de709c3335cc5a3850476"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1d51aff78f078af1a80e9496c2f4643f4c0ef0a0"
}
],
"schema_version": "1.4.0",
"severity": []
}
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.
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.