CVE-2025-39939

Aliases:UBUNTU-CVE-2025-39939DEBIAN-CVE-2025-39939
Advisory lineage Upstream: 0 Downstream: 4
Modified
Published: 04 Oct 2025, 07:31
Last modified:05 Aug 2026, 12:06

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (nvd)
EPSS Score
0.14% LOW
0% probability +0.12%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

04 Oct 2025, 07:31
Published
Vulnerability first disclosed
05 Aug 2026, 12:06
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/s390: Fix memory corruption when using identity domain zpci_get_iommu_ctrs() returns counter information to be reported as part of device statistics; these counters are stored as part of the s390_domain. The problem, however, is that the identity domain is not backed by an s390_domain and so the conversion via to_s390_domain() yields a bad address that is zero'd initially and read on-demand later via a sysfs read. These counters aren't necessary for the identity domain; just return NULL in this case. This issue was discovered via KASAN with reports that look like: BUG: KASAN: global-out-of-bounds in zpci_fmb_enable_device when using the identity domain for a device on s390.

CVSS Metrics

  • v3.1HIGHScore: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.14% Percentile: 4%

Techniques & Countermeasures

  • CWE-787Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • debianlinux

    < 6.16.9-1

  • ubuntulinux-allwinner-5.19

    all

  • ubuntulinux-aws-5.0

    all

  • ubuntulinux-aws-5.11

    all

  • ubuntulinux-aws-5.13

    all

  • ubuntulinux-aws-5.19

    all

  • ubuntulinux-aws-5.3

    all

  • ubuntulinux-aws-5.8

    all

  • ubuntulinux-aws-6.2

    all

  • ubuntulinux-aws-6.5

    all

  • ubuntulinux-azure

    all

  • ubuntulinux-azure-5.11

    all

  • ubuntulinux-azure-5.13

    all

  • ubuntulinux-azure-5.19

    all

  • ubuntulinux-azure-5.3

    all

  • ubuntulinux-azure-5.8

    all

  • ubuntulinux-azure-6.11

    all

  • ubuntulinux-azure-6.2

    all

  • ubuntulinux-azure-6.5

    all

  • ubuntulinux-azure-edge

    all

  • ubuntulinux-azure-fde

    all | all

  • ubuntulinux-azure-fde-5.19

    all

  • ubuntulinux-azure-fde-6.2

    all

  • ubuntulinux-bluefield

    all

  • ubuntulinux-gcp

    all

  • ubuntulinux-gcp-5.11

    all

  • ubuntulinux-gcp-5.13

    all

  • ubuntulinux-gcp-5.19

    all

  • ubuntulinux-gcp-5.3

    all

  • ubuntulinux-gcp-5.8

    all

  • ubuntulinux-gcp-6.11

    all

  • ubuntulinux-gcp-6.2

    all

  • ubuntulinux-gcp-6.5

    all

  • ubuntulinux-gke

    all

  • ubuntulinux-gke-4.15

    all

  • ubuntulinux-gke-5.15

    all

  • ubuntulinux-gke-5.4

    all

  • ubuntulinux-gkeop

    all

  • ubuntulinux-gkeop-5.15

    all

  • ubuntulinux-gkeop-5.4

    all

  • ubuntulinux-hwe

    all

  • ubuntulinux-hwe-5.11

    all

  • ubuntulinux-hwe-5.13

    all

  • ubuntulinux-hwe-5.19

    all

  • ubuntulinux-hwe-5.8

    all

  • ubuntulinux-hwe-6.11

    all

  • ubuntulinux-hwe-6.2

    all

  • ubuntulinux-hwe-6.5

    all

  • ubuntulinux-hwe-edge

    all | all

  • ubuntulinux-intel

    all

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References (6)