mptcp: fix uninitialized local_id in syncookie MP_JOIN reconstruction (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.60 % · percentile 49 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Received
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix uninitialized local_id in syncookie MP_JOIN reconstruction mptcp_token_join_cookie_init_state() restores remote_nonce, local_nonce, backup, join_id, token and msk from the saved cookie entry when rebuilding the request socket for a MP_JOIN 4th-ACK handled under SYN cookies, but it does not restore local_id, even though the SYN path saved it. subflow_ulp_clone() then reads that uninitialized field and stores it as the joined subflow's address-ID. Because the request-sock slab is SLAB_TYPESAFE_BY_RCU and not zeroed on allocation, the value is the stale byte of a previously freed request socket, which an off-path peer can influence by sending concurrent MP_JOIN SYNs. This corrupts the path manager's id-based subflow bookkeeping for the connection. Restore subflow_req->local_id from the cookie entry, as done for the other fields.
References
- https://git.kernel.org/stable/c/4534e0eead692bb069ad1e6a5a245fc2e2078300
- https://git.kernel.org/stable/c/63cacb05e51a1c6e1349d2e593d00fd6ef43def4
- https://git.kernel.org/stable/c/954b5ea836eb118d188975ced803448537ab8479
- https://git.kernel.org/stable/c/9df36a4846375a9b75bf42d77bfed216b0f366f9
- https://git.kernel.org/stable/c/64f2c5dd49b956a542c8c02b8dad5d262a462bba
- https://git.kernel.org/stable/c/51887ccd88791ddaa8755a7c614fda031ecf7982
- https://git.kernel.org/stable/c/bf19d166337c6488b39cb03eeeffb30a941d6326
- https://git.kernel.org/stable/c/b878dfdd12d7a5b8722a78d35e313506140ca3d9
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H | Linux |
| CVSS 3.1 | HIGH 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-76465
- GCVE · GCVE-0-2026-89554
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1375 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1289 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1253 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 < 4534e0eead692bb069ad1e6a5a245fc2e2078300 ; affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 < 63cacb05e51a1c6e1349d2e593d00fd6ef43def4 ; affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 < 954b5ea836eb118d188975ced803448537ab8479 ; affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 < 9df36a4846375a9b75bf42d77bfed216b0f366f9 ; affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 < 64f2c5dd49b956a542c8c02b8dad5d262a462bba ; affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 < 51887ccd88791ddaa8755a7c614fda031ecf7982 |
| Linux · Linux | affected 5.9 ; unaffected 0 < 5.9 ; unaffected 5.10.270 ≤ 5.10.* ; unaffected 5.15.221 ≤ 5.15.* ; unaffected 6.1.188 ≤ 6.1.* ; unaffected 6.6.157 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |