AZL-100725
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-100725.json
- JSON Data
- https://api.osv.dev/v1/vulns/AZL-100725
- Upstream
- Published
- 2026-09-11T20:19:39Z
- Modified
- 2026-09-12T14:15:31Z
- Summary
- CVE-2026-89554 affecting package kernel 6.6.150.1-1
- Details
-
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