Tracker / CVE-2021-47491
CVE-2021-47491
Medium 5.5
In the Linux kernel, the following vulnerability has been resolved: mm: khugepaged: skip huge page collapse for special files The read-only THP for filesystems will collapse THP for files opened readonly and mapped with VM_EXEC. The intended usecase is to avoid TLB misses for large text segments. But it doesn't restrict the file types so a THP could be collapsed for a non-regular file, for example, block device, if it is opened readonly and mapped with EXEC permission. This may cause bugs, like [1] and [2]. This is definitely not the intended usecase, so just collapse THP for regular files in order to close the attack surface. [[email protected]: fix vm_file check [3]]
Affected products and versions
| linux | linux_kernel |
|---|---|
| linux | linux_kernel · 5.11 → 5.14.16 |
| linux | linux_kernel · 5.4 → 5.10.78 |
Analysis
This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.