CVE-2026-97524 (GCVE-0-2026-97524)
Vulnerability from cvelistv5
Published
2026-09-25 10:21
Modified
2026-10-19 09:08
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: mptcp: avoid unneeded actions on subflow reset Once in a blue moon, the mptcp receive path can recursively call mptcp_data_ready() via state change under unlucky error conditions, and then try to hold the data lock again. Break the recursion loop explicitly checking for the exceptional condition. Add a new flag instead of using an existing one like 'closing', to exit early in subflow_state_change(), and explicitly flush the RX queue at reset time. This avoids unneeded processing to check for available data -- calling get_mapping_status() and more on a dying subflow -- but also in error reporting and worker scheduling. Note that we must consume the currently peeked skb before invoking mptcp_dss_corruption to avoid consuming it again after the eventual reset has freed it.
References
Impacted products
Vendor Product Version
Linux Linux Version: fde99e972b8f88cebe619241d7aa43d288ef666a
Version: 12c1676d598e3b8dd92a033b623b792cc2ea1ec5
Version: 35668f8ec84f6c944676e48ecc6bbc5fc8e6fe25
Version: b8be15d1ae7ea4eedd547c3b3141f592fbddcd30
Version: e32d262c89e2b22cb0640223f953b548617ed8a6
Version: e32d262c89e2b22cb0640223f953b548617ed8a6
Version: e32d262c89e2b22cb0640223f953b548617ed8a6
Version: e32d262c89e2b22cb0640223f953b548617ed8a6
Version: 8bfd391bde685df7289b928ce8876a3583be4bfb
Version: 5.10.228   ≤
Version: 5.15.169   ≤
Version: 6.1.113   ≤
Version: 6.6.57   ≤
Version: 6.11.4   ≤
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/mptcp/protocol.c",
            "net/mptcp/protocol.h",
            "net/mptcp/subflow.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6d669c740933124eae3df8cfc15995af9bcc6aba",
              "status": "affected",
              "version": "fde99e972b8f88cebe619241d7aa43d288ef666a",
              "versionType": "git"
            },
            {
              "lessThan": "83a7dcdd2b1060484528da70a643125174d47e5a",
              "status": "affected",
              "version": "12c1676d598e3b8dd92a033b623b792cc2ea1ec5",
              "versionType": "git"
            },
            {
              "lessThan": "a370e56024df0b07e3120c45a9773ae123819fd6",
              "status": "affected",
              "version": "35668f8ec84f6c944676e48ecc6bbc5fc8e6fe25",
              "versionType": "git"
            },
            {
              "lessThan": "1962841387087970d75ba8b8d4c2aa2d45705e50",
              "status": "affected",
              "version": "b8be15d1ae7ea4eedd547c3b3141f592fbddcd30",
              "versionType": "git"
            },
            {
              "lessThan": "4b7abdcb5ba832fafab679f0d998af39cbc99307",
              "status": "affected",
              "version": "e32d262c89e2b22cb0640223f953b548617ed8a6",
              "versionType": "git"
            },
            {
              "lessThan": "b2dbcc1ed48b5ac070a41db4a52aade6823c4df0",
              "status": "affected",
              "version": "e32d262c89e2b22cb0640223f953b548617ed8a6",
              "versionType": "git"
            },
            {
              "lessThan": "ce7e4ede01ed3e47a48c0f1ce1d87bf4864bee9f",
              "status": "affected",
              "version": "e32d262c89e2b22cb0640223f953b548617ed8a6",
              "versionType": "git"
            },
            {
              "lessThan": "2b0f561f21b27c40c91ea4975268a06092bd7e9c",
              "status": "affected",
              "version": "e32d262c89e2b22cb0640223f953b548617ed8a6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8bfd391bde685df7289b928ce8876a3583be4bfb",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.271",
              "status": "affected",
              "version": "5.10.228",
              "versionType": "semver"
            },
            {
              "lessThan": "5.15.222",
              "status": "affected",
              "version": "5.15.169",
              "versionType": "semver"
            },
            {
              "lessThan": "6.1.189",
              "status": "affected",
              "version": "6.1.113",
              "versionType": "semver"
            },
            {
              "lessThan": "6.6.158",
              "status": "affected",
              "version": "6.6.57",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12",
              "status": "affected",
              "version": "6.11.4",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/mptcp/protocol.c",
            "net/mptcp/protocol.h",
            "net/mptcp/subflow.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.271",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.222",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.271",
                  "versionStartIncluding": "5.10.228",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.222",
                  "versionStartIncluding": "5.15.169",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.189",
                  "versionStartIncluding": "6.1.113",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.158",
                  "versionStartIncluding": "6.6.57",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.7",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.11.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: avoid unneeded actions on subflow reset\n\nOnce in a blue moon, the mptcp receive path can recursively call\nmptcp_data_ready() via state change under unlucky error conditions, and\nthen try to hold the data lock again.\n\nBreak the recursion loop explicitly checking for the exceptional\ncondition.\n\nAdd a new flag instead of using an existing one like \u0027closing\u0027, to exit\nearly in subflow_state_change(), and explicitly flush the RX queue at\nreset time.\n\nThis avoids unneeded processing to check for available data -- calling\nget_mapping_status() and more on a dying subflow -- but also in error\nreporting and worker scheduling.\n\nNote that we must consume the currently peeked skb before invoking\nmptcp_dss_corruption to avoid consuming it again after the eventual\nreset has freed it."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - A crafted MPTCP DSS option on a received TCP segment is the attacker-controlled input; it is parsed on the established RX path tcp_rcv_established \u2192 tcp_data_queue \u2192 subflow_data_ready \u2192 mptcp_data_ready \u2192 __mptcp_move_skbs_from_subflow, which calls mptcp_dss_corruption() and then the patched mptcp_subflow_reset()/subflow_state_change(). MPTCP/TCP is a routable IP protocol.\nAC:L - The peer disables infinite fallback via MP_JOIN (mptcp_subflow_joined(); allow_join_initial_addr_port defaults to 1) or by filling msk-\u003eout_of_order_queue, then sends a DSS with data_len shorter than the skb plus another TCP-ofo segment so map_remaining \u003c len in __mptcp_move_skbs_from_subflow() calls mptcp_subflow_reset() while ssk-\u003esk_receive_queue is still occupied, making subflow_state_change() re-enter mptcp_data_ready().\nPR:N - The DSS is processed in TCP receive softirq after an unauthenticated MP_CAPABLE handshake with an IPPROTO_MPTCP listener (or an outbound MPTCP client); no local account, capability, or application credential is checked on the path to mptcp_dss_corruption().\nUI:N - The attacker\u2019s DSS segments are handled entirely in RX softirq on an existing MPTCP connection; no local user mount, file open, or other victim action is required.\nS:U - The recursive mptcp_data_lock hang and subflow teardown stay inside the victim kernel\u2019s network stack; no VM, IOMMU, or sandbox boundary is crossed.\nC:N - The defect is a nested spin_lock_bh on sk-\u003esk_lock.slock from subflow_state_change() back into mptcp_data_ready(); it does not read attacker-chosen kernel memory or leak pointers.\nI:N - Pre-fix tcp_done() does not purge ssk-\u003esk_receive_queue, and the nested mptcp_data_ready() never proceeds past the already-held slock, so there is no use-after-free, write primitive, or control-flow hijack.\nA:H - mptcp_data_ready() already holds mptcp_data_lock (spin_lock_bh on sk-\u003esk_lock.slock) when mptcp_dss_corruption() \u2192 mptcp_subflow_reset() \u2192 tcp_done() invokes subflow_state_change(), which re-enters mptcp_data_ready() and deadlocks the CPU in softirq (soft lockup)."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:08:42.302Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6d669c740933124eae3df8cfc15995af9bcc6aba"
        },
        {
          "url": "https://git.kernel.org/stable/c/83a7dcdd2b1060484528da70a643125174d47e5a"
        },
        {
          "url": "https://git.kernel.org/stable/c/a370e56024df0b07e3120c45a9773ae123819fd6"
        },
        {
          "url": "https://git.kernel.org/stable/c/1962841387087970d75ba8b8d4c2aa2d45705e50"
        },
        {
          "url": "https://git.kernel.org/stable/c/4b7abdcb5ba832fafab679f0d998af39cbc99307"
        },
        {
          "url": "https://git.kernel.org/stable/c/b2dbcc1ed48b5ac070a41db4a52aade6823c4df0"
        },
        {
          "url": "https://git.kernel.org/stable/c/ce7e4ede01ed3e47a48c0f1ce1d87bf4864bee9f"
        },
        {
          "url": "https://git.kernel.org/stable/c/2b0f561f21b27c40c91ea4975268a06092bd7e9c"
        }
      ],
      "title": "mptcp: avoid unneeded actions on subflow reset",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-97524",
    "datePublished": "2026-09-25T10:21:27.668Z",
    "dateReserved": "2026-09-24T16:01:01.152Z",
    "dateUpdated": "2026-10-19T09:08:42.302Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.