In the Linux kernel before 5.1.6, there is a use-after-free in serial_ir_init_module() in drivers/media/rc/serial_ir.c.
Reference and upstream commit:
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1781811]
This was fixed for Fedora with the 5.1.6 stable kernel update.
So, I'm rating this moderate, because:
:- only able to be triggered during the failure to load the module
:- triggerable only during the load of the module ( administrative privileges required).
This doesn't qualify for Z stream/EUS fixes but if you have hardware / a situation that this can be triggered on, I'd be willing to change my mind.
As the module will be auto-loaded when the relevant hardware is required, its use can be disabled by preventing the module from loading with the following instructions:
# echo "install serial_ir /bin/true" >> /etc/modprobe.d/disable-serial-ir.conf
The system will need to be restarted if the CIFS modules are loaded. In most circumstances, the CIFS kernel modules will be unable to be unloaded while any network interfaces are active and the protocol is in use.
If the system requires this module to work correctly, this mitigation may not be suitable.
If you need further assistance, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.