During the Upgrade of Oracle Linux 7.2 to 7.3 with “yum update”, when updating the microcode_ctl package, the system crashed and firmware reported an uncorrectable CPU error after reboot.

It turned out that the update of the package in combination with specific Intel CPUs causes the issue. In the meantime, there is a red hat bug and solution available.

References:

• https://community.oracle.com/thread/3997160
• https://bugzilla.redhat.com/show_bug.cgi?id=1398698
• MOS: The system could not start since suddenly rebooted during upgrade to microcode_ctl package (Doc ID 2217876.1)