CVE-2023-53438
Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
18/09/2025
Última modificación:
19/09/2025
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
x86/MCE: Always save CS register on AMD Zen IF Poison errors<br />
<br />
The Instruction Fetch (IF) units on current AMD Zen-based systems do not<br />
guarantee a synchronous #MC is delivered for poison consumption errors.<br />
Therefore, MCG_STATUS[EIPV|RIPV] will not be set. However, the<br />
microarchitecture does guarantee that the exception is delivered within<br />
the same context. In other words, the exact rIP is not known, but the<br />
context is known to not have changed.<br />
<br />
There is no architecturally-defined method to determine this behavior.<br />
<br />
The Code Segment (CS) register is always valid on such IF unit poison<br />
errors regardless of the value of MCG_STATUS[EIPV|RIPV].<br />
<br />
Add a quirk to save the CS register for poison consumption from the IF<br />
unit banks.<br />
<br />
This is needed to properly determine the context of the error.<br />
Otherwise, the severity grading function will assume the context is<br />
IN_KERNEL due to the m->cs value being 0 (the initialized value). This<br />
leads to unnecessary kernel panics on data poison errors due to the<br />
kernel believing the poison consumption occurred in kernel context.