Out-of-bounds Write Affecting kernel-tools-libs package, versions *


Severity

Recommended
low

Based on CentOS security rating.

Threat Intelligence

EPSS
0.16% (6th percentile)

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  • Snyk IDSNYK-CENTOS10-KERNELTOOLSLIBS-18050171
  • published21 Jul 2026
  • disclosed19 Jul 2026

Introduced: 19 Jul 2026

NewCVE-2026-64186  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

There is no fixed version for Centos:10 kernel-tools-libs.

NVD Description

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

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

iommu/amd: Remove latent out-of-bounds access in IOMMU debugfs

In iommu_mmio_write() and iommu_capability_write(), the variables dbg_mmio_offset and dbg_cap_offset are declared as int. However, they are populated using kstrtou32_from_user(). If a user provides a sufficiently large value, it can become a negative integer.

Prior to this patch, the AMD IOMMU debugfs implementation was already protected by different mechanisms.

  1. #define OFS_IN_SZ 8 ensures the user string <= 8 bytes, so e.g. 0xffffffff isn't a valid input.

if (cnt > OFS_IN_SZ) return -EINVAL;

  1. Implicit type promotion in iommu_mmio_write(), dbg_mmio_offset is int and iommu->mmio_phys_end is u64

if (dbg_mmio_offset > iommu->mmio_phys_end - sizeof(u64)) return -EINVAL;

  1. The show handlers would currently catch the negative number and refuse to perform the read.

Replace kstrtou32_from_user() with kstrtos32_from_user() to parse the input, and check for negative values to explicitly prevent out-of-bounds memory accesses directly in iommu_mmio_write() and iommu_capability_write().

CVSS Base Scores

version 3.1