Improper Input Validation Affecting kernel-doc package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Improper Input Validation vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-RHEL6-KERNELDOC-8222296
  • published16 Oct 2024
  • disclosed15 Oct 2024

Introduced: 15 Oct 2024

CVE-2024-47674  (opens in a new tab)
CWE-20  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:6 kernel-doc.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-doc package and not the kernel-doc package as distributed by RHEL. See How to fix? for RHEL:6 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

mm: avoid leaving partial pfn mappings around in error case

As Jann points out, PFN mappings are special, because unlike normal memory mappings, there is no lifetime information associated with the mapping - it is just a raw mapping of PFNs with no reference counting of a 'struct page'.

That's all very much intentional, but it does mean that it's easy to mess up the cleanup in case of errors. Yes, a failed mmap() will always eventually clean up any partial mappings, but without any explicit lifetime in the page table mapping itself, it's very easy to do the error handling in the wrong order.

In particular, it's easy to mistakenly free the physical backing store before the page tables are actually cleaned up and (temporarily) have stale dangling PTE entries.

To make this situation less error-prone, just make sure that any partial pfn mapping is torn down early, before any other error handling.

CVSS Scores

version 3.1