Hello FreewheelinFrank
As usual huge thanks for the reply
You're welcome!
You are correct in answering your first question.
If there is a hardware switch for SMT, kernel mitigation can't be applied.
Confirmed by your output:
Code:
cat /sys/devices/system/cpu/vulnerabilities/mdsMitigation: Clear CPU buffers; SMT vulnerableI am with the impression that GRUB_CMDLINE_LINUX_DEFAULT="quiet splash mds=off" only hides the bug message, Am I correct?
That setting will disable buffer clearing and enable SMT (on CPUs without the BIOS setting for SMT). You may actually see more warnings, in dmesg or journalctl at least. This is not a bug. The kernel is warning of a vulnerability. It's up yo you what you decide to do about it.
The quote is from the page link given in the journalctl output.
https://www.kernel.org/doc/html/latest/ ... ion-guide
The bold content, pls could you share some examples?
The Ubuntu knowledgebase article (linked to before) has some examples.
https://ubuntu.com/security/vulnerabilities/mds
A web search for "MDS CPU bug present and SMT on, data leak possible" also finds a lot more information.
I am not recommending that you or anybody else turn off mitigation, or advising that it is safe to do so. It's really up to you to read as much information as you can, and make an informed decision based on what you are running.
As you have mitigation applied for vmscape, you also need to apply the same process for that: be thoroughly sure it is safe to do so for you before you make any changes.
Code:
cat /sys/devices/system/cpu/vulnerabilities/vmscapeMitigation: IBPB before exit to userspacehttps://www.kernel.org/doc/html/latest/ ... scape.html
Statistics: Posted by FreewheelinFrank — 2026-01-26 06:14