While Meltdown and Spectre Variant 1 could be theoretically being addressed by patching the OS, Spectre Variant 2 require a firmware/microcode update to address the issue.
Now Red Hat joint to the list of companies that observed problems after the installation of the patches, it is releasing updates that are reverting previous patches for the Spectre vulnerability (Variant 2, aka CVE-2017-5715).
The company decided to revert the initial security updates because it received from some customers complaints about booting failure for their systems.
Red Hat is recommending its customers to contact their OEM hardware provider to receive the latest release of firmware to mitigate the CVE-2017-5715.
“Red Hat Security is currently recommending that subscribers contact their CPU OEM vendor to download the latest microcode/firmware for their processor.” reads the advisory published by Red Hat.
“The latest microcode_ctl and linux-firmware packages from Red Hat do not include resolutions to the CVE-2017-5715 (variant 2) exploit. Red Hat is no longer providing microcode to address Spectre, variant 2, due to instabilities introduced that are causing customer systems to not boot. The latest microcode_ctl and linux-firmware packages are reverting these unstable microprocessor firmware changes to versions that were known to be stable and well tested, released prior to the Spectre/Meltdown embargo lift date on Jan 3rd. Customers are advised to contact their silicon vendor to get the latest microcode for their particular processor.”
Other distributions based on Red Hat Enterprise Linux like CentOS could suffer similar problems and it could be necessary to revert Spectre Variant 2 security updates.
The company suggests customers to access the Red Hat Customer Portal Lab App to verify systems have the necessary microprocessor firmware to address CVE-2017-5715 (variant 2):
(Security Affairs – Spectre security updates, CVE-2017-5715)