In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: free sk if last When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(), and released at the end. If at that moment, it was the last reference being held, the sk would not be freed. sock_put() should then be called instead of __sock_put(). But that's not enough: if it is the last reference, sock_put() will call sk_free(), which will end up calling sk_stop_timer_sync() on the same timer, and waiting indefinitely to finish. So it is needed to mark that the timer is done at the end of the timer handler when it has not been rescheduled, not to call sk_stop_timer_sync() on "itself".

A flaw was found in the Linux kernel's Multipath TCP (MPTCP) implementation. When an ADD_ADDR message is retransmitted, an issue in socket (sk) reference counting can prevent the socket from being properly freed. This improper resource management may lead to a Denial of Service (DoS) condition, where the system could become unresponsive due to indefinite waiting during timer synchronization.

Red Hat Enterprise Linux 10 Affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Affected kernel Red Hat Enterprise Linux 8 Affected kernel-rt Red Hat Enterprise Linux 9 Affected kernel Red Hat Enterprise Linux 9 Affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-46170 https://nvd.nist.gov/vuln/detail/CVE-2026-46170 https://lore.kernel.org/linux-cve-announce/2026052827-CVE-2026-46170-b7ab@gregkh/T