Vulnerability-Lookup

CVE-2026-98432 (GCVE-0-2026-98432)

Vulnerability from cvelistv5 – Published: 2026-10-15 12:08 – Updated: 2026-10-15 12:19

Title

ipv4: free inet_opt and ireq_opt after an RCU grace period

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv4: free inet_opt and ireq_opt after an RCU grace period tcp_v4_syn_recv_sock() transfers ownership of ireq->ireq_opt to the child socket (newinet->inet_opt) without copying it. Another cpu can concurrently process a retransmitted SYN for the same request socket, and send a SYNACK from tcp_check_req(). tcp_v4_send_synack() and inet_csk_route_req() read ireq->ireq_opt under rcu_read_lock() only, and ip_build_and_send_pkt() and ip_options_build() then read opt->optlen twice. Note that the SYNACK timer itself is not an issue: it holds a reference on its request socket, and inet_csk_reqsk_queue_drop() calls timer_delete_sync() before the child can be freed. Since commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table"), request sockets are processed without holding the listener lock, so nothing prevents the child socket from being freed while the SYNACK is still being built. TCP child sockets do not have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt with a plain kfree(), leading to a use-after-free in ip_options_build(). A similar issue exists with request socket migration (net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE program). reqsk_timer_handler() clones the request socket with inet_reqsk_clone(), so that the old request socket and its clone share the same ireq_opt, then reqsk_migrate_reset() clears the pointer in the old one. Another cpu holding a reference on the old request socket can still be using these options (sending a SYNACK, or creating a child in tcp_v4_syn_recv_sock()) when the clone is freed, and tcp_v4_reqsk_destructor() also uses a plain kfree(). Readers already use RCU, and other paths replacing inet_opt (do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use kfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and tcp_v4_reqsk_destructor() as well. IPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock() duplicates the options. tcp_v6_reqsk_destructor() has the same migration issue with ipv6_opt, which is only set by CALIPSO. This will be addressed in a separate patch.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6667 records in the last 180 days details

References

8 references

URL	Tags
https://git.kernel.org/stable/c/b3b027ef0cd322bfa…
https://git.kernel.org/stable/c/95a8c8fa9f27dce64…
https://git.kernel.org/stable/c/89b5b1eb7d633c338…
https://git.kernel.org/stable/c/742f73df544e03744…
https://git.kernel.org/stable/c/11a03ce3c4a62d84c…
https://git.kernel.org/stable/c/a47406c769f72c070…
https://git.kernel.org/stable/c/26d4c36d318cffbbd…
https://git.kernel.org/stable/c/e3f33b0a1d89d738e…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < b3b027ef0cd322bfa839b9aaf5b27551eea54cf6 (git) Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < 95a8c8fa9f27dce64c40c41c062de7728bf34ab5 (git) Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < 89b5b1eb7d633c33832b7ff2c02e19a144705036 (git) Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < 742f73df544e03744f2981c467d6542fe8172a2a (git) Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < 11a03ce3c4a62d84c10ccdfe47f8075006498568 (git) Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < a47406c769f72c070386985488f1c4d057df86b2 (git) Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < 26d4c36d318cffbbd160884a0e4cec0da4da4936 (git) Affected: 079096f103faca2dd87342cca6f23d4b34da8871 , < e3f33b0a1d89d738e2b913dab519226eaf76e15b (git)	guessed
Linux	Linux	Affected: 4.4 Unaffected: 0 , < 4.4 (semver) Unaffected: 5.10.272 , ≤ 5.10.* (semver) Unaffected: 5.15.223 , ≤ 5.15.* (semver) Unaffected: 6.1.190 , ≤ 6.1.* (semver) Unaffected: 6.6.159 , ≤ 6.6.* (semver) Unaffected: 6.12.113 , ≤ 6.12.* (semver) Unaffected: 6.18.56 , ≤ 6.18.* (semver) Unaffected: 7.2.10 , ≤ 7.2.* (semver) Unaffected: 7.3-rc7 , ≤ * (original_commit_for_fix)	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/af_inet.c",
            "net/ipv4/tcp_ipv4.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "89b5b1eb7d633c33832b7ff2c02e19a144705036",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "742f73df544e03744f2981c467d6542fe8172a2a",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "11a03ce3c4a62d84c10ccdfe47f8075006498568",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "a47406c769f72c070386985488f1c4d057df86b2",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "26d4c36d318cffbbd160884a0e4cec0da4da4936",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "e3f33b0a1d89d738e2b913dab519226eaf76e15b",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/af_inet.c",
            "net/ipv4/tcp_ipv4.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.4"
            },
            {
              "lessThan": "4.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.272",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.223",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.190",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.159",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc7",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.272",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.223",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.190",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.159",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc7",
                  "versionStartIncluding": "4.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: free inet_opt and ireq_opt after an RCU grace period\n\ntcp_v4_syn_recv_sock() transfers ownership of ireq-\u003eireq_opt to the\nchild socket (newinet-\u003einet_opt) without copying it.\n\nAnother cpu can concurrently process a retransmitted SYN for the same\nrequest socket, and send a SYNACK from tcp_check_req().\ntcp_v4_send_synack() and inet_csk_route_req() read ireq-\u003eireq_opt\nunder rcu_read_lock() only, and ip_build_and_send_pkt() and\nip_options_build() then read opt-\u003eoptlen twice.\n\nNote that the SYNACK timer itself is not an issue: it holds a\nreference on its request socket, and inet_csk_reqsk_queue_drop()\ncalls timer_delete_sync() before the child can be freed.\n\nSince commit 079096f103fa (\"tcp/dccp: install syn_recv requests\ninto ehash table\"), request sockets are processed without holding\nthe listener lock, so nothing prevents the child socket from being\nfreed while the SYNACK is still being built. TCP child sockets do\nnot have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt\nwith a plain kfree(), leading to a use-after-free in\nip_options_build().\n\nA similar issue exists with request socket migration\n(net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE\nprogram). reqsk_timer_handler() clones the request socket with\ninet_reqsk_clone(), so that the old request socket and its clone\nshare the same ireq_opt, then reqsk_migrate_reset() clears the\npointer in the old one. Another cpu holding a reference on the old\nrequest socket can still be using these options (sending a SYNACK,\nor creating a child in tcp_v4_syn_recv_sock()) when the clone is\nfreed, and tcp_v4_reqsk_destructor() also uses a plain kfree().\n\nReaders already use RCU, and other paths replacing inet_opt\n(do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use\nkfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and\ntcp_v4_reqsk_destructor() as well.\n\nIPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock()\nduplicates the options. tcp_v6_reqsk_destructor() has the same\nmigration issue with ipv6_opt, which is only set by CALIPSO. This\nwill be addressed in a separate patch."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-15T12:19:54.582Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6"
        },
        {
          "url": "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5"
        },
        {
          "url": "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036"
        },
        {
          "url": "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a"
        },
        {
          "url": "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568"
        },
        {
          "url": "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2"
        },
        {
          "url": "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936"
        },
        {
          "url": "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b"
        }
      ],
      "title": "ipv4: free inet_opt and ireq_opt after an RCU grace period",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98432",
    "datePublished": "2026-10-15T12:08:22.205Z",
    "dateReserved": "2026-09-25T10:25:14.348Z",
    "dateUpdated": "2026-10-15T12:19:54.582Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "net/ipv4/af_inet.c",
                  "net/ipv4/tcp_ipv4.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "89b5b1eb7d633c33832b7ff2c02e19a144705036",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "742f73df544e03744f2981c467d6542fe8172a2a",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "11a03ce3c4a62d84c10ccdfe47f8075006498568",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "a47406c769f72c070386985488f1c4d057df86b2",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "26d4c36d318cffbbd160884a0e4cec0da4da4936",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "e3f33b0a1d89d738e2b913dab519226eaf76e15b",
                    "status": "affected",
                    "version": "079096f103faca2dd87342cca6f23d4b34da8871",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "net/ipv4/af_inet.c",
                  "net/ipv4/tcp_ipv4.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "4.4"
                  },
                  {
                    "lessThan": "4.4",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.10.*",
                    "status": "unaffected",
                    "version": "5.10.272",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.15.*",
                    "status": "unaffected",
                    "version": "5.15.223",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.1.*",
                    "status": "unaffected",
                    "version": "6.1.190",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.6.*",
                    "status": "unaffected",
                    "version": "6.6.159",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.113",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.56",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.10",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3-rc7",
                    "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\nipv4: free inet_opt and ireq_opt after an RCU grace period\n\ntcp_v4_syn_recv_sock() transfers ownership of ireq-\u003eireq_opt to the\nchild socket (newinet-\u003einet_opt) without copying it.\n\nAnother cpu can concurrently process a retransmitted SYN for the same\nrequest socket, and send a SYNACK from tcp_check_req().\ntcp_v4_send_synack() and inet_csk_route_req() read ireq-\u003eireq_opt\nunder rcu_read_lock() only, and ip_build_and_send_pkt() and\nip_options_build() then read opt-\u003eoptlen twice.\n\nNote that the SYNACK timer itself is not an issue: it holds a\nreference on its request socket, and inet_csk_reqsk_queue_drop()\ncalls timer_delete_sync() before the child can be freed.\n\nSince commit 079096f103fa (\"tcp/dccp: install syn_recv requests\ninto ehash table\"), request sockets are processed without holding\nthe listener lock, so nothing prevents the child socket from being\nfreed while the SYNACK is still being built. TCP child sockets do\nnot have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt\nwith a plain kfree(), leading to a use-after-free in\nip_options_build().\n\nA similar issue exists with request socket migration\n(net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE\nprogram). reqsk_timer_handler() clones the request socket with\ninet_reqsk_clone(), so that the old request socket and its clone\nshare the same ireq_opt, then reqsk_migrate_reset() clears the\npointer in the old one. Another cpu holding a reference on the old\nrequest socket can still be using these options (sending a SYNACK,\nor creating a child in tcp_v4_syn_recv_sock()) when the clone is\nfreed, and tcp_v4_reqsk_destructor() also uses a plain kfree().\n\nReaders already use RCU, and other paths replacing inet_opt\n(do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use\nkfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and\ntcp_v4_reqsk_destructor() as well.\n\nIPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock()\nduplicates the options. tcp_v6_reqsk_destructor() has the same\nmigration issue with ipv6_opt, which is only set by CALIPSO. This\nwill be addressed in a separate patch."
          }
        ],
        "id": "CVE-2026-98432",
        "lastModified": "2026-10-15T13:17:13.987",
        "metrics": {},
        "published": "2026-10-15T13:17:13.987",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    }
  }
}

FKIE_CVE-2026-98432

Vulnerability from fkie_nvd - Published: 2026-10-15 13:17 - Updated: 2026-10-15 13:17

Severity

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/af_inet.c",
            "net/ipv4/tcp_ipv4.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "89b5b1eb7d633c33832b7ff2c02e19a144705036",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "742f73df544e03744f2981c467d6542fe8172a2a",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "11a03ce3c4a62d84c10ccdfe47f8075006498568",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "a47406c769f72c070386985488f1c4d057df86b2",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "26d4c36d318cffbbd160884a0e4cec0da4da4936",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            },
            {
              "lessThan": "e3f33b0a1d89d738e2b913dab519226eaf76e15b",
              "status": "affected",
              "version": "079096f103faca2dd87342cca6f23d4b34da8871",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/af_inet.c",
            "net/ipv4/tcp_ipv4.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.4"
            },
            {
              "lessThan": "4.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.272",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.223",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.190",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.159",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc7",
              "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\nipv4: free inet_opt and ireq_opt after an RCU grace period\n\ntcp_v4_syn_recv_sock() transfers ownership of ireq-\u003eireq_opt to the\nchild socket (newinet-\u003einet_opt) without copying it.\n\nAnother cpu can concurrently process a retransmitted SYN for the same\nrequest socket, and send a SYNACK from tcp_check_req().\ntcp_v4_send_synack() and inet_csk_route_req() read ireq-\u003eireq_opt\nunder rcu_read_lock() only, and ip_build_and_send_pkt() and\nip_options_build() then read opt-\u003eoptlen twice.\n\nNote that the SYNACK timer itself is not an issue: it holds a\nreference on its request socket, and inet_csk_reqsk_queue_drop()\ncalls timer_delete_sync() before the child can be freed.\n\nSince commit 079096f103fa (\"tcp/dccp: install syn_recv requests\ninto ehash table\"), request sockets are processed without holding\nthe listener lock, so nothing prevents the child socket from being\nfreed while the SYNACK is still being built. TCP child sockets do\nnot have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt\nwith a plain kfree(), leading to a use-after-free in\nip_options_build().\n\nA similar issue exists with request socket migration\n(net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE\nprogram). reqsk_timer_handler() clones the request socket with\ninet_reqsk_clone(), so that the old request socket and its clone\nshare the same ireq_opt, then reqsk_migrate_reset() clears the\npointer in the old one. Another cpu holding a reference on the old\nrequest socket can still be using these options (sending a SYNACK,\nor creating a child in tcp_v4_syn_recv_sock()) when the clone is\nfreed, and tcp_v4_reqsk_destructor() also uses a plain kfree().\n\nReaders already use RCU, and other paths replacing inet_opt\n(do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use\nkfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and\ntcp_v4_reqsk_destructor() as well.\n\nIPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock()\nduplicates the options. tcp_v6_reqsk_destructor() has the same\nmigration issue with ipv6_opt, which is only set by CALIPSO. This\nwill be addressed in a separate patch."
    }
  ],
  "id": "CVE-2026-98432",
  "lastModified": "2026-10-15T13:17:13.987",
  "metrics": {},
  "published": "2026-10-15T13:17:13.987",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-QP6H-4HVH-QQQC

Vulnerability from github – Published: 2026-10-15 18:32 – Updated: 2026-10-15 18:32

Details

In the Linux kernel, the following vulnerability has been resolved:

ipv4: free inet_opt and ireq_opt after an RCU grace period

tcp_v4_syn_recv_sock() transfers ownership of ireq->ireq_opt to the child socket (newinet->inet_opt) without copying it.

Another cpu can concurrently process a retransmitted SYN for the same request socket, and send a SYNACK from tcp_check_req(). tcp_v4_send_synack() and inet_csk_route_req() read ireq->ireq_opt under rcu_read_lock() only, and ip_build_and_send_pkt() and ip_options_build() then read opt->optlen twice.

Note that the SYNACK timer itself is not an issue: it holds a reference on its request socket, and inet_csk_reqsk_queue_drop() calls timer_delete_sync() before the child can be freed.

Since commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table"), request sockets are processed without holding the listener lock, so nothing prevents the child socket from being freed while the SYNACK is still being built. TCP child sockets do not have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt with a plain kfree(), leading to a use-after-free in ip_options_build().

A similar issue exists with request socket migration (net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE program). reqsk_timer_handler() clones the request socket with inet_reqsk_clone(), so that the old request socket and its clone share the same ireq_opt, then reqsk_migrate_reset() clears the pointer in the old one. Another cpu holding a reference on the old request socket can still be using these options (sending a SYNACK, or creating a child in tcp_v4_syn_recv_sock()) when the clone is freed, and tcp_v4_reqsk_destructor() also uses a plain kfree().

Readers already use RCU, and other paths replacing inet_opt (do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use kfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and tcp_v4_reqsk_destructor() as well.

IPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock() duplicates the options. tcp_v6_reqsk_destructor() has the same migration issue with ipv6_opt, which is only set by CALIPSO. This will be addressed in a separate patch.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-98432"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-15T13:17:13Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: free inet_opt and ireq_opt after an RCU grace period\n\ntcp_v4_syn_recv_sock() transfers ownership of ireq-\u003eireq_opt to the\nchild socket (newinet-\u003einet_opt) without copying it.\n\nAnother cpu can concurrently process a retransmitted SYN for the same\nrequest socket, and send a SYNACK from tcp_check_req().\ntcp_v4_send_synack() and inet_csk_route_req() read ireq-\u003eireq_opt\nunder rcu_read_lock() only, and ip_build_and_send_pkt() and\nip_options_build() then read opt-\u003eoptlen twice.\n\nNote that the SYNACK timer itself is not an issue: it holds a\nreference on its request socket, and inet_csk_reqsk_queue_drop()\ncalls timer_delete_sync() before the child can be freed.\n\nSince commit 079096f103fa (\"tcp/dccp: install syn_recv requests\ninto ehash table\"), request sockets are processed without holding\nthe listener lock, so nothing prevents the child socket from being\nfreed while the SYNACK is still being built. TCP child sockets do\nnot have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt\nwith a plain kfree(), leading to a use-after-free in\nip_options_build().\n\nA similar issue exists with request socket migration\n(net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE\nprogram). reqsk_timer_handler() clones the request socket with\ninet_reqsk_clone(), so that the old request socket and its clone\nshare the same ireq_opt, then reqsk_migrate_reset() clears the\npointer in the old one. Another cpu holding a reference on the old\nrequest socket can still be using these options (sending a SYNACK,\nor creating a child in tcp_v4_syn_recv_sock()) when the clone is\nfreed, and tcp_v4_reqsk_destructor() also uses a plain kfree().\n\nReaders already use RCU, and other paths replacing inet_opt\n(do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use\nkfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and\ntcp_v4_reqsk_destructor() as well.\n\nIPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock()\nduplicates the options. tcp_v6_reqsk_destructor() has the same\nmigration issue with ipv6_opt, which is only set by CALIPSO. This\nwill be addressed in a separate patch.",
  "id": "GHSA-qp6h-4hvh-qqqc",
  "modified": "2026-10-15T18:32:33Z",
  "published": "2026-10-15T18:32:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98432"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b"
    }
  ],
  "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-98432 (GCVE-0-2026-98432)

FKIE_CVE-2026-98432

GHSA-QP6H-4HVH-QQQC

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour