CVE-2025-39939

HIGH EPSS 3.1%
Published Oct 4, 20259mo ago · Modified Jun 17, 20262w ago
7.8 CVSS 3.1
High
Find Similar
Published Oct 4, 2025 9mo ago
Last Modified Jun 17, 2026 2w ago

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 Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
3.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-787 Out-of-bounds Write Memory Safety

Affected Products 7

VendorProductVersionRange
linuxlinux_kernel*≥6.15  –  <6.16.9
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any

References 2

  • git.kernel.org https://git.kernel.org/stable/c/17a58caf3863163c4a84a218a9649be2c8061443
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b3506e9bcc777ed6af2ab631c86a9990ed97b474
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/17a58caf3863163c4a84a218a9649be2c8061443
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b3506e9bcc777ed6af2ab631c86a9990ed97b474
    Patch