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netfilter: nf_tables: fix use-after-free in nf_tables_addchain()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with no RCU grace period in between. This creates two use-after-free conditions: 1) Control-plane: nf_tables_dump_chains() traverses table->chains under rcu_read_lock(). A concurrent dump can still be walking the chain when the error path frees it. 2) Packet path: for NFPROTO_INET, nf_register_net_hook() briefly installs the IPv4 hook before IPv6 registration fails. Packets entering nft_do_chain() via the transient IPv4 hook can still be dereferencing chain->blob_gen_X when the error path frees the chain. Add synchronize_rcu() between nft_chain_del() and the chain destroy so that all RCU readers -- both dump threads and in-flight packet evaluation -- have finished before the chain is freed.

Announced Source revision 1
Original source ↗

CVE-2026-23231

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-23231

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "91c7b38dc9f0de4f7f444b796d14476bc12df7bc",
        "lessThan": "2a6586ecfa4ce1413daaafee250d2590e05f1a33",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "91c7b38dc9f0de4f7f444b796d14476bc12df7bc",
        "lessThan": "7017745068a9068904e1e7a1b170a5785647cc81",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "91c7b38dc9f0de4f7f444b796d14476bc12df7bc",
        "lessThan": "f3fe58ce37926a10115ede527d59b91bcc05400a",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "91c7b38dc9f0de4f7f444b796d14476bc12df7bc",
        "lessThan": "dbd0af8083dd201f07c49110b2ee93710abdff28",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "91c7b38dc9f0de4f7f444b796d14476bc12df7bc",
        "lessThan": "2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "91c7b38dc9f0de4f7f444b796d14476bc12df7bc",
        "lessThan": "71e99ee20fc3f662555118cf1159443250647533",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/netfilter/nf_tables_api.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.16"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.16",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.1.165",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.128",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.75",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.14",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "6.19.4",
        "versionType": "semver",
        "lessThanOrEqual": "6.19.*"
      },
      {
        "status": "unaffected",
        "version": "7.0",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/netfilter/nf_tables_api.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-23231

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#39823 · Revision 1
Added to Heist Feed
Publisher date
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