CVE-2025-21709 Affecting kernel-rt-trace-devel package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating.

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  • Snyk IDSNYK-CENTOS7-KERNELRTTRACEDEVEL-9032900
  • published2 Mar 2025
  • disclosed27 Feb 2025

Introduced: 27 Feb 2025

NewCVE-2025-21709  (opens in a new tab)

How to fix?

There is no fixed version for Centos:7 kernel-rt-trace-devel.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-trace-devel package and not the kernel-rt-trace-devel package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

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

kernel: be more careful about dup_mmap() failures and uprobe registering

If a memory allocation fails during dup_mmap(), the maple tree can be left in an unsafe state for other iterators besides the exit path. All the locks are dropped before the exit_mmap() call (in mm/mmap.c), but the incomplete mm_struct can be reached through (at least) the rmap finding the vmas which have a pointer back to the mm_struct.

Up to this point, there have been no issues with being able to find an mm_struct that was only partially initialised. Syzbot was able to make the incomplete mm_struct fail with recent forking changes, so it has been proven unsafe to use the mm_struct that hasn't been initialised, as referenced in the link below.

Although 8ac662f5da19f ("fork: avoid inappropriate uprobe access to invalid mm") fixed the uprobe access, it does not completely remove the race.

This patch sets the MMF_OOM_SKIP to avoid the iteration of the vmas on the oom side (even though this is extremely unlikely to be selected as an oom victim in the race window), and sets MMF_UNSTABLE to avoid other potential users from using a partially initialised mm_struct.

When registering vmas for uprobe, skip the vmas in an mm that is marked unstable. Modifying a vma in an unstable mm may cause issues if the mm isn't fully initialised.

CVSS Scores

version 3.1