CVE-2026-64123 (GCVE-0-2026-64123)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:40 – Updated: 2026-07-20 13:43
VLAI
Title
net: hsr: defer node table free until after RCU readers
Summary
In the Linux kernel, the following vulnerability has been resolved: net: hsr: defer node table free until after RCU readers HSR node-list and node-status generic-netlink operations run under rcu_read_lock(). They walk hsr->node_db through hsr_get_next_node() and hsr_get_node_data(), but RTM_DELLINK teardown removes the same node table with plain list_del() and frees each node immediately. That lets a generic-netlink reader hold a struct hsr_node pointer across hsr_dellink(). In a KASAN build, widening the reader window after hsr_get_next_node() obtains the node reproduces a slab-use-after-free when the reader copies node->macaddress_A; the freeing stack is hsr_del_nodes() from hsr_dellink(). Use list_del_rcu() and defer the free through the existing hsr_free_node_rcu() callback. This matches the lifetime rule used by the HSR prune paths, which already delete nodes with list_del_rcu() and call_rcu().
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
Linux Linux Affected: b9a1e627405d68d475a3c1f35e685ccfb5bbe668 , < 0ea70fb46940620848c08d9d399455c9e82fecdb (git)
Affected: b9a1e627405d68d475a3c1f35e685ccfb5bbe668 , < 8be6685cdd1255bcc85f9b59e4bfc313aefc5c1b (git)
Affected: b9a1e627405d68d475a3c1f35e685ccfb5bbe668 , < c5580114e0492bcd2e0a37613ed4c311e3fa3d4d (git)
Affected: b9a1e627405d68d475a3c1f35e685ccfb5bbe668 , < 7713f4aafb577ff49fa67f0488d9c7dddc64d6ce (git)
Affected: b9a1e627405d68d475a3c1f35e685ccfb5bbe668 , < 6324423a8e6591f41a16c09a8f9a84e554ac147c (git)
Affected: b9a1e627405d68d475a3c1f35e685ccfb5bbe668 , < 8c3af18bb0d7c921a5219194037509463eb2ffde (git)
Affected: b9a1e627405d68d475a3c1f35e685ccfb5bbe668 , < aaec7096f9961eb223b5b149abe9495525c205d9 (git)
Affected: 08523d5a2f4a9e4202e00d282c164d453cabe2d2 (git)
Affected: 5.2.12 , < 5.3 (semver)
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Linux Linux Affected: 5.3
Unaffected: 0 , < 5.3 (semver)
Unaffected: 5.10.259 , ≤ 5.10.* (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.93 , ≤ 6.12.* (semver)
Unaffected: 7.0.11 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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    "datePublished": "2026-07-19T15:40:21.161Z",
    "dateReserved": "2026-07-19T07:54:57.036Z",
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-20T16:47:47+00:00",
      "cve": "CVE-2026-64123",
      "id": "CVE-2026-64123",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "91",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net: hsr: defer node table free until after RCU readers",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64123.json",
      "version": "3"
    }
  }
}



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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.