CVE-2024-44974

In the Linux kernel, the following vulnerability has been resolved:

mptcp: pm: avoid possible UaF when selecting endp

select_local_address() and select_signal_address() both select an endpoint entry from the list inside an RCU protected section, but return a reference to it, to be read later on. If the entry is dereferenced after the RCU unlock, reading info could cause a Use-after-Free.

A simple solution is to copy the required info while inside the RCU protected section to avoid any risk of UaF later. The address ID might need to be modified later to handle the ID0 case later, so a copy seems OK to deal with.

This vulnerability is rated as Moderate because exploitation requires concurrent manipulation of Multipath TCP (MPTCP) path manager endpoints, potentially resulting in a kernel crash or memory corruption. MPTCP is not utilized by default network traffic on Red Hat Enterprise Linux, as services must explicitly establish MPTCP sockets or use specialized protocol wrappers. Consequently, the blast radius is restricted to systems actively deploying MPTCP endpoints, preventing widespread unauthenticated exploitation.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.