GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-72072 (GCVE-0-2026-72072)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:52 – Updated: 2026-08-17 05:40
VLAI
Title
net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete
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).
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: b7c9400cbc48c3713190b3bce4e0c87e924e4104 , < b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb (git)
Affected: b7c9400cbc48c3713190b3bce4e0c87e924e4104 , < 218cc15a4c907659ad4b0e68c535c61594311205 (git)
Affected: b7c9400cbc48c3713190b3bce4e0c87e924e4104 , < 4a5073b7b30243658f58b2d2d35a823da7fd34d9 (git)
Affected: b7c9400cbc48c3713190b3bce4e0c87e924e4104 , < ed3cc4218070d6b98bf5fb456dccae424fd38c4f (git)
Affected: b7c9400cbc48c3713190b3bce4e0c87e924e4104 , < 088873af13590ebde10de2ade847f57a05ec61c6 (git)
Affected: b7c9400cbc48c3713190b3bce4e0c87e924e4104 , < de74d8fd10291763d97b218f09adcc7513c975e4 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.1
Unaffected: 0 , < 6.1 (semver)
Unaffected: 6.1.178 , ≤ 6.1.* (semver)
Unaffected: 6.6.145 , ≤ 6.6.* (semver)
Unaffected: 6.12.97 , ≤ 6.12.* (semver)
Unaffected: 6.18.40 , ≤ 6.18.* (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.178",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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)."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The UAF is reached by racing MACSEC_CMD_DEL_RXSC/ADD_RXSC netlink configuration (GENL_ADMIN_PERM) against mlx5e MACsec RX processing; the privileged genlink/rtnl control path is required to trigger the bug, not remote packets alone.\nAC:L - An attacker with CAP_NET_ADMIN can drive both sides by looping RX SC add/delete while flooding MACsec-offloaded RX traffic on the mlx5e netdev, reliably winning the RCU race between xa_load/dst_hold and metadata_dst_free.\nPR:L - MACsec offload mutations require GENL_ADMIN_PERM (CAP_NET_ADMIN); on Mellanox ConnectX/BlueField systems this is reachable by cloud tenants with SR-IOV VFs, containers, or user/network namespaces without init-namespace root.\nUI:N - No victim user action is needed; automated concurrent netlink MACsec operations and incoming MACsec-offloaded frames on an active mlx5e interface suffice once MACsec offload is configured.\nS:U - Impact is kernel heap use-after-free and memory corruption within the host kernel on the mlx5 NIC; it enables local privilege escalation but does not by itself cross VM, IOMMU, or hypervisor security boundaries.\nC:H - The race calls dst_hold() and skb_dst_set() on a freed metadata_dst, a classic slab UAF that can disclose kernel memory through subsequent dst_entry and MACsec skb metadata handling.\nI:H - Freed metadata_dst objects can be reallocated via heap spraying while the RX datapath still references them, enabling refcount corruption and arbitrary kernel memory writes or control-flow hijack beyond a mere crash.\nA:H - Concurrent use of freed md_dst during mlx5e MACsec RX processing can cause immediate kernel oops, BUG, or panic on datacenter/cloud hosts using mlx5 hardware MACsec offload, fully denying system availability."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:40:03.099Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb"
        },
        {
          "url": "https://git.kernel.org/stable/c/218cc15a4c907659ad4b0e68c535c61594311205"
        },
        {
          "url": "https://git.kernel.org/stable/c/4a5073b7b30243658f58b2d2d35a823da7fd34d9"
        },
        {
          "url": "https://git.kernel.org/stable/c/ed3cc4218070d6b98bf5fb456dccae424fd38c4f"
        },
        {
          "url": "https://git.kernel.org/stable/c/088873af13590ebde10de2ade847f57a05ec61c6"
        },
        {
          "url": "https://git.kernel.org/stable/c/de74d8fd10291763d97b218f09adcc7513c975e4"
        }
      ],
      "title": "net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72072",
    "datePublished": "2026-08-15T05:52:23.946Z",
    "dateReserved": "2026-08-09T03:40:39.904Z",
    "dateUpdated": "2026-08-17T05:40:03.099Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-72072",
      "date": "2026-09-04",
      "epss": "0.00171",
      "percentile": "0.06645"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-72072\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T06:21:16.943\",\"lastModified\":\"2026-08-17T06:18:05.787\",\"vulnStatus\":\"Received\",\"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).\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"b7c9400cbc48c3713190b3bce4e0c87e924e4104\",\"lessThan\":\"b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"b7c9400cbc48c3713190b3bce4e0c87e924e4104\",\"lessThan\":\"218cc15a4c907659ad4b0e68c535c61594311205\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"b7c9400cbc48c3713190b3bce4e0c87e924e4104\",\"lessThan\":\"4a5073b7b30243658f58b2d2d35a823da7fd34d9\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"b7c9400cbc48c3713190b3bce4e0c87e924e4104\",\"lessThan\":\"ed3cc4218070d6b98bf5fb456dccae424fd38c4f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"b7c9400cbc48c3713190b3bce4e0c87e924e4104\",\"lessThan\":\"088873af13590ebde10de2ade847f57a05ec61c6\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"b7c9400cbc48c3713190b3bce4e0c87e924e4104\",\"lessThan\":\"de74d8fd10291763d97b218f09adcc7513c975e4\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.1\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.1\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.178\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.145\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.97\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"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\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-17T21:38:11+00:00",
      "cve": "CVE-2026-72072",
      "id": "CVE-2026-72072",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "198",
      "product_status:known_not_affected": "76",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72072.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.