Riskcovery

CVE-2025-38733

s390/mm: Do not map lowcore with identity mapping

State
Published
Severity
7.8 High
Published
Sep 5, 2025
Updated
Oct 15, 2026
Reserved
Apr 16, 2025

Read the record on cve.org

Description

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

s390/mm: Do not map lowcore with identity mapping

Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once.

This means that NULL pointer accesses will succeed instead of causing an exception (low address protection still applies, but covers only parts). To fix this never map the first two pages of physical memory with the identity mapping.

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 32db401965f165f7c44447d0508097f070c8f576 to before 30bf5728bb217a6d1ba73f44094c9b9c6bc9a567Affected
  • 32db401965f165f7c44447d0508097f070c8f576 to before 1d7864acd497cb468a998d44631f84896f885e85Affected
  • 32db401965f165f7c44447d0508097f070c8f576 to before 93f616ff870a1fb7e84d472cad0af651b18f9f87Affected
  • 0b99d0e17d6a73a0526f92bc6b54b2b95e67a31dAffected
  • 6.10.11 to before 6.11Affected
LinuxLinux
  • 6.11Affected
  • before 6.11Not affected
  • 6.12.44 through 6.12.*Not affected
  • 6.16.4 through 6.16.*Not affected
  • 6.17 and laterNot affected

References

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