Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
efivarfs: Rate limit statfs() handler
Ravi reports that statfs() may be called by unprivileged users on the efivarfs mount point, which may result in a flood of calls to the QueryVariableInfo() runtime service. These calls are disproportionately costly on x86 systems where the variable store is backed by SMM, as each SMM entry requires a rendez-vous of all the CPUs.
So rate limit the calls to QueryVariableInfo() at twice per second, and return the most recently obtained value for calls that are elided.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS
- Affected packages:
- linux @ 5.10.259 (+1 more)