CVE-2025-68179
Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
16/12/2025
Última modificación:
18/12/2025
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
s390: Disable ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP<br />
<br />
As reported by Luiz Capitulino enabling HVO on s390 leads to reproducible<br />
crashes. The problem is that kernel page tables are modified without<br />
flushing corresponding TLB entries.<br />
<br />
Even if it looks like the empty flush_tlb_all() implementation on s390 is<br />
the problem, it is actually a different problem: on s390 it is not allowed<br />
to replace an active/valid page table entry with another valid page table<br />
entry without the detour over an invalid entry. A direct replacement may<br />
lead to random crashes and/or data corruption.<br />
<br />
In order to invalidate an entry special instructions have to be used<br />
(e.g. ipte or idte). Alternatively there are also special instructions<br />
available which allow to replace a valid entry with a different valid<br />
entry (e.g. crdte or cspg).<br />
<br />
Given that the HVO code currently does not provide the hooks to allow for<br />
an implementation which is compliant with the s390 architecture<br />
requirements, disable ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP again, which is<br />
basically a revert of the original patch which enabled it.



