In the Linux kernel, the following vulnerability has been resolved:
llc: fix SAP refcount leak in llc_ui_autobind()
llc_ui_autobind() opens a SAP after choosing a dynamic LSAP. llc_sap_open() returns a reference owned by the caller, and llc_sap_add_socket() takes a second reference for the sockets membership in the SAP hash tables.
llc_ui_bind() drops the callers reference after adding the socket, but llc_ui_autobind() keeps it. When the socket is closed, llc_sap_remove_socket() releases only the socket reference, leaving the SAP on llc_sap_list with sk_count == 0.
This is user-visible because repeated autobind and close cycles can consume all dynamic SAP values and make later autobinds fail with -EUSERS.
Drop the callers reference after a successful autobind, matching llc_ui_bind()s ownership model.
References
- https://git.kernel.org/stable/c/21a537606fe35be2b85971a5fd35c0023b6ef98f
- https://git.kernel.org/stable/c/61a7ff4a62003b55a15022567486741b3bd83914
- https://git.kernel.org/stable/c/660667cd406648bbaffbd5c0d897c2263a852f11
- https://git.kernel.org/stable/c/79dc4b508e3f2649390a1f745f7657813e5938ec
- https://git.kernel.org/stable/c/a2f9fa31ae021ef1fdcaf3ab17bd49f9223dd6a4
- https://git.kernel.org/stable/c/b2fc9955ddc7c4ca03be44b995193bd6486c62e1
- https://git.kernel.org/stable/c/b589a965184dde49c43b8caf5bcc65715a7b4ef2
- https://git.kernel.org/stable/c/c7881b6088276601beaccb7440b8d56eab0d65ae