Overview
About vulnerability
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 socket’s membership in the SAP hash tables.
llc_ui_bind() drops the caller’s 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 caller’s reference after a successful autobind, matching llc_ui_bind()’s ownership model.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+4 more)