FKIE_CVE-2026-72072
Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete
When an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed
the per-SC metadata_dst with metadata_dst_free(), which kfree()s the
object unconditionally and ignores the dst reference count. The RX
datapath in mlx5e_macsec_offload_handle_rx_skb() looks up the SC under
rcu_read_lock() via xa_load(), takes a reference with dst_hold() and
attaches the dst to the skb with skb_dst_set(). A reader that already
obtained the rx_sc pointer can race with the delete path and operate on
freed memory.
Fix the owner side by dropping the reference with dst_release() instead
of freeing unconditionally, and convert the RX datapath to
dst_hold_safe() so a reader racing the SC delete cannot attach a dst
whose last reference was just dropped; only attach it when a reference
was actually taken.
mlx5e_macsec_add_rxsc() also published sc_xarray_element via xa_alloc()
before rx_sc->md_dst was allocated and initialised, so a datapath reader
that looked the SC up by fs_id could observe rx_sc with md_dst still
NULL or, on weakly-ordered architectures, a non-NULL md_dst pointer
whose contents were not yet visible. NULL-check the xa_load() result and
md_dst on the datapath, and reorder add_rxsc() so the xa_alloc() publish
happens only after md_dst is fully initialised; the xarray RCU publish
then pairs with the rcu_read_lock()/xa_load() in the datapath.
Note: macsec_del_rxsc_ctx() also kfree()s rx_sc->sc_xarray_element
without an RCU grace period while the same datapath reads it under
rcu_read_lock(); that is a separate pre-existing issue left to a
follow-up patch.
Found by 0sec automated security-research tooling (https://0sec.ai).
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb",
"status": "affected",
"version": "b7c9400cbc48c3713190b3bce4e0c87e924e4104",
"versionType": "git"
},
{
"lessThan": "218cc15a4c907659ad4b0e68c535c61594311205",
"status": "affected",
"version": "b7c9400cbc48c3713190b3bce4e0c87e924e4104",
"versionType": "git"
},
{
"lessThan": "4a5073b7b30243658f58b2d2d35a823da7fd34d9",
"status": "affected",
"version": "b7c9400cbc48c3713190b3bce4e0c87e924e4104",
"versionType": "git"
},
{
"lessThan": "ed3cc4218070d6b98bf5fb456dccae424fd38c4f",
"status": "affected",
"version": "b7c9400cbc48c3713190b3bce4e0c87e924e4104",
"versionType": "git"
},
{
"lessThan": "088873af13590ebde10de2ade847f57a05ec61c6",
"status": "affected",
"version": "b7c9400cbc48c3713190b3bce4e0c87e924e4104",
"versionType": "git"
},
{
"lessThan": "de74d8fd10291763d97b218f09adcc7513c975e4",
"status": "affected",
"version": "b7c9400cbc48c3713190b3bce4e0c87e924e4104",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"lessThan": "6.1",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete\n\nWhen an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed\nthe per-SC metadata_dst with metadata_dst_free(), which kfree()s the\nobject unconditionally and ignores the dst reference count. The RX\ndatapath in mlx5e_macsec_offload_handle_rx_skb() looks up the SC under\nrcu_read_lock() via xa_load(), takes a reference with dst_hold() and\nattaches the dst to the skb with skb_dst_set(). A reader that already\nobtained the rx_sc pointer can race with the delete path and operate on\nfreed memory.\n\nFix the owner side by dropping the reference with dst_release() instead\nof freeing unconditionally, and convert the RX datapath to\ndst_hold_safe() so a reader racing the SC delete cannot attach a dst\nwhose last reference was just dropped; only attach it when a reference\nwas actually taken.\n\nmlx5e_macsec_add_rxsc() also published sc_xarray_element via xa_alloc()\nbefore rx_sc-\u003emd_dst was allocated and initialised, so a datapath reader\nthat looked the SC up by fs_id could observe rx_sc with md_dst still\nNULL or, on weakly-ordered architectures, a non-NULL md_dst pointer\nwhose contents were not yet visible. NULL-check the xa_load() result and\nmd_dst on the datapath, and reorder add_rxsc() so the xa_alloc() publish\nhappens only after md_dst is fully initialised; the xarray RCU publish\nthen pairs with the rcu_read_lock()/xa_load() in the datapath.\n\nNote: macsec_del_rxsc_ctx() also kfree()s rx_sc-\u003esc_xarray_element\nwithout an RCU grace period while the same datapath reads it under\nrcu_read_lock(); that is a separate pre-existing issue left to a\nfollow-up patch.\n\nFound by 0sec automated security-research tooling (https://0sec.ai)."
}
],
"id": "CVE-2026-72072",
"lastModified": "2026-08-17T06:18:05.787",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-15T06:21:16.943",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/088873af13590ebde10de2ade847f57a05ec61c6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/218cc15a4c907659ad4b0e68c535c61594311205"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4a5073b7b30243658f58b2d2d35a823da7fd34d9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/de74d8fd10291763d97b218f09adcc7513c975e4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ed3cc4218070d6b98bf5fb456dccae424fd38c4f"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
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.
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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.
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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