Out-of-bounds Read Affecting kernel-modules-extra-matched package, versions *


Severity

Recommended
medium

Based on Red Hat Enterprise Linux security rating.

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  • Snyk IDSNYK-RHEL10-KERNELMODULESEXTRAMATCHED-13973311
  • published14 Nov 2025
  • disclosed12 Nov 2025

Introduced: 12 Nov 2025

NewCVE-2025-40199  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-modules-extra-matched.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-modules-extra-matched package and not the kernel-modules-extra-matched package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

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

page_pool: Fix PP_MAGIC_MASK to avoid crashing on some 32-bit arches

Helge reported that the introduction of PP_MAGIC_MASK let to crashes on boot on his 32-bit parisc machine. The cause of this is the mask is set too wide, so the page_pool_page_is_pp() incurs false positives which crashes the machine.

Just disabling the check in page_pool_is_pp() will lead to the page_pool code itself malfunctioning; so instead of doing this, this patch changes the define for PP_DMA_INDEX_BITS to avoid mistaking arbitrary kernel pointers for page_pool-tagged pages.

The fix relies on the kernel pointers that alias with the pp_magic field always being above PAGE_OFFSET. With this assumption, we can use the lowest bit of the value of PAGE_OFFSET as the upper bound of the PP_DMA_INDEX_MASK, which should avoid the false positives.

Because we cannot rely on PAGE_OFFSET always being a compile-time constant, nor on it always being >0, we fall back to disabling the dma_index storage when there are not enough bits available. This leaves us in the situation we were in before the patch in the Fixes tag, but only on a subset of architecture configurations. This seems to be the best we can do until the transition to page types in complete for page_pool pages.

v2:

  • Make sure there's at least 8 bits available and that the PAGE_OFFSET bit calculation doesn't wrap

CVSS Base Scores

version 3.1