In the Linux kernel, the following vulnerability has been...
Moderate severity
Unreviewed
Published
Oct 22, 2025
to the GitHub Advisory Database
•
Updated Oct 22, 2025
Description
Published by the National Vulnerability Database
Feb 26, 2025
Published to the GitHub Advisory Database
Oct 22, 2025
Last updated
Oct 22, 2025
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits
Use the recently introduced __try_cmpxchg_user() to update guest PTE A/D
bits instead of mapping the PTE into kernel address space. The VM_PFNMAP
path is broken as it assumes that vm_pgoff is the base pfn of the mapped
VMA range, which is conceptually wrong as vm_pgoff is the offset relative
to the file and has nothing to do with the pfn. The horrific hack worked
for the original use case (backing guest memory with /dev/mem), but leads
to accessing "random" pfns for pretty much any other VM_PFNMAP case.
References