CVE-2020-10781

A flaw was found in the ZRAM kernel module, where a user with a local account and the ability to read the /sys/class/zram-control/hot_add file can create ZRAM device nodes in the /dev/ directory. This read allocates kernel memory and is not accounted for a user that triggers the creation of that ZRAM device. With this vulnerability, continually reading the device may consume a large amount of system memory and cause the Out-of-Memory (OOM) killer to activate and terminate random userspace processes, possibly making the system inoperable.

Mitigation

Changing permissions on the files within /sys will prevent regular users from being able to trigger this issue, however permissions changed within /sys do not persist between reboots and will need to be reapplied after each boot.