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

net: ch9200: fix uninitialised access during mii_nway_restart

In mii_nway_restart() the code attempts to call
mii->mdio_read which is ch9200_mdio_read(). ch9200_mdio_read()
utilises a local buffer called "buff", which is initialised
with control_read(). However "buff" is conditionally
initialised inside control_read():

if (err == size) {
memcpy(data, buf, size);
}

If the condition of "err == size" is not met, then
"buff" remains uninitialised. Once this happens the
uninitialised "buff" is accessed and returned during
ch9200_mdio_read():

return (buff[0] | buff[1] << 8);

The problem stems from the fact that ch9200_mdio_read()
ignores the return value of control_read(), leading to
uinit-access of "buff".

To fix this we should check the return value of
control_read() and return early on error.
Published: 2025-06-28
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4327-1 linux security update
Debian DLA Debian DLA DLA-4328-1 linux-6.1 security update
Debian DSA Debian DSA DSA-5973-1 linux security update
EUVD EUVD EUVD-2025-19447 In the Linux kernel, the following vulnerability has been resolved: net: ch9200: fix uninitialised access during mii_nway_restart In mii_nway_restart() the code attempts to call mii->mdio_read which is ch9200_mdio_read(). ch9200_mdio_read() utilises a local buffer called "buff", which is initialised with control_read(). However "buff" is conditionally initialised inside control_read(): if (err == size) { memcpy(data, buf, size); } If the condition of "err == size" is not met, then "buff" remains uninitialised. Once this happens the uninitialised "buff" is accessed and returned during ch9200_mdio_read(): return (buff[0] | buff[1] << 8); The problem stems from the fact that ch9200_mdio_read() ignores the return value of control_read(), leading to uinit-access of "buff". To fix this we should check the return value of control_read() and return early on error.
Ubuntu USN Ubuntu USN USN-7774-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7774-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7774-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7775-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7775-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7776-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7775-3 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7774-4 Linux kernel (KVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7774-5 Linux kernel (NVIDIA Tegra IGX) vulnerabilities
Ubuntu USN Ubuntu USN USN-7833-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7834-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7833-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7833-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7833-4 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-7856-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8031-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-4 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-5 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8031-2 Linux kernel (GCP FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-6 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8031-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8052-1 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-7 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-8 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8052-2 Linux kernel (Xilinx) vulnerabilities
Ubuntu USN Ubuntu USN USN-8074-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8074-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8126-1 Linux kernel (Azure) vulnerabilities
History

Wed, 17 Dec 2025 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
CPEs cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.3:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.3:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.3:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.3:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.3:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.3:rc7:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Mon, 03 Nov 2025 18:30:00 +0000


Tue, 01 Jul 2025 14:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-908

Mon, 30 Jun 2025 12:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Sat, 28 Jun 2025 08:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: ch9200: fix uninitialised access during mii_nway_restart In mii_nway_restart() the code attempts to call mii->mdio_read which is ch9200_mdio_read(). ch9200_mdio_read() utilises a local buffer called "buff", which is initialised with control_read(). However "buff" is conditionally initialised inside control_read(): if (err == size) { memcpy(data, buf, size); } If the condition of "err == size" is not met, then "buff" remains uninitialised. Once this happens the uninitialised "buff" is accessed and returned during ch9200_mdio_read(): return (buff[0] | buff[1] << 8); The problem stems from the fact that ch9200_mdio_read() ignores the return value of control_read(), leading to uinit-access of "buff". To fix this we should check the return value of control_read() and return early on error.
Title net: ch9200: fix uninitialised access during mii_nway_restart
References

Subscriptions

Debian Debian Linux
Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T21:20:59.045Z

Reserved: 2025-04-16T04:51:23.981Z

Link: CVE-2025-38086

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-06-28T08:15:24.997

Modified: 2025-12-17T16:36:11.670

Link: CVE-2025-38086

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-06-28T00:00:00Z

Links: CVE-2025-38086 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-06T22:16:28Z

Weaknesses