CVE-2025-38086

high

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.

References

https://git.kernel.org/stable/c/cdaa6d1cb2ff1219c6c822b27655dd170ffb0f72

https://git.kernel.org/stable/c/9da3e442714f7f4393ff01c265c4959c03e88c2f

https://git.kernel.org/stable/c/9ad0452c0277b816a435433cca601304cfac7c21

https://git.kernel.org/stable/c/9a350f30d65197354706b7759b5c89d6c267b1a9

https://git.kernel.org/stable/c/6bd2569d0b2f918e9581f744df0263caf73ee76c

https://git.kernel.org/stable/c/4da7fcc098218ff92b2e83a43f545c02f714cedd

https://git.kernel.org/stable/c/33163c68d2e3061fa3935b5f0a1867958b1cdbd2

https://git.kernel.org/stable/c/119766de4930ff40db9f36b960cb53b0c400e81b

Details

Source: Mitre, NVD

Published: 2025-06-28

Updated: 2025-06-30

Risk Information

CVSS v2

Base Score: 5.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Severity: High

EPSS

EPSS: 0.00024