CVE-2026-89604

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd86ff3333cb1d5f42d8898fb5fdb304e143c0237 < 8953bdd1b9c0e748d5408d3d0b8e7aeee5c9cd41affected
LinuxLinuxd86ff3333cb1d5f42d8898fb5fdb304e143c0237 < 92895a14329cc9533e2a74a265214f690ba3851aaffected
LinuxLinuxd86ff3333cb1d5f42d8898fb5fdb304e143c0237 < 0dbc2e94b81df5a1264068b6ed3605c654b8afcbaffected
LinuxLinuxd86ff3333cb1d5f42d8898fb5fdb304e143c0237 < b2326338dc683e8c1067c0cbf7a47986c4190902affected
LinuxLinux115409cbb6a296d73702a62c54c5b1b11cb88b3daffected
LinuxLinux6.1.178 < 6.2affected
LinuxLinux6.5affected
LinuxLinux0 < 6.5unaffected
LinuxLinux6.12.109 <= 6.12.*unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References