CVE-2024-53122: mptcp: cope racing subflow creation in mptcp_rcv_space_adjust

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-12-02 · updated 2026-10-15
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: cope racing subflow creation in mptcp_rcv_space_adjust Additional active subflows - i.e. created by the in kernel path manager - are included into the subflow list before starting the 3whs. A racing recvmsg() spooling data received on an already established subflow would unconditionally call tcp_cleanup_rbuf() on all the current subflows, potentially hitting a divide by zero error on the newly created ones. Explicitly check that the subflow is in a suitable state before invoking tcp_cleanup_rbuf().

Affected products

Linux kernel: from 5.10 before 6.1.119; from 6.2 before 6.6.63; from 6.7 before 6.11.10; 6.12-rc1, 6.12-rc2, 6.12-rc3, 6.12-rc4, 6.12-rc5, 6.12-rc6 (+1) — fixed in 6.1.119, 6.11.10, 6.6.63

How to fix

Upgrade to a fixed version: Linux kernel 6.1.119, 6.11.10, 6.6.63. Check the vendor advisory for mitigations.

References

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