CVE-2024-45009 Information

Description

In the Linux kernel the following vulnerability has been resolved:

mptcp: pm: only decrement add_addr_accepted for MPJ req

Adding the following warning …

WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)

… before decrementing the add_addr_accepted counter helped to find a bug when running the emove single subflow\ subtest from the mptcp_join.sh selftest.

Removing a ‘subflow’ endpoint will first trigger a RM_ADDR then the subflow closure. Before this patch and upon the reception of the RM_ADDR the other peer will then try to decrement this add_addr_accepted. That’s not correct because the attached subflows have not been created upon the reception of an ADD_ADDR.

A way to solve that is to decrement the counter only if the attached subflow was an MP_JOIN to a remote id that was not 0 and initiated by the host receiving the RM_ADDR.

Reference

https://git.kernel.org/stable/c/85b866e4c4e63a1d7afb58f1e24273caad03d0b7 https://git.kernel.org/stable/c/d20bf2c96d7ffd171299b32f562f70e5bf5dc608 https://git.kernel.org/stable/c/2060f1efab370b496c4903b840844ecaff324c3c https://git.kernel.org/stable/c/1c1f721375989579e46741f59523e39ec9b2a9bd