CVE-2025-38086
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.
CVSS Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Threat Intelligence
Weaknesses 1
Affected Products 14
| Vendor | Product | Version | Range |
|---|---|---|---|
| linux | linux_kernel | * | ≥4.3.1 – <5.4.295 |
| linux | linux_kernel | * | ≥5.5 – <5.10.239 |
| linux | linux_kernel | * | ≥5.11 – <5.15.186 |
| linux | linux_kernel | * | ≥5.16 – <6.1.142 |
| linux | linux_kernel | * | ≥6.2 – <6.6.95 |
| linux | linux_kernel | * | ≥6.7 – <6.12.35 |
| linux | linux_kernel | * | ≥6.13 – <6.15.4 |
| linux | linux_kernel | 4.3 | any |
| linux | linux_kernel | 4.3 | any |
| linux | linux_kernel | 4.3 | any |
| linux | linux_kernel | 4.3 | any |
| linux | linux_kernel | 4.3 | any |
| linux | linux_kernel | 4.3 | any |
| debian | debian_linux | 11.0 | any |
References 10
- git.kernel.org https://git.kernel.org/stable/c/119766de4930ff40db9f36b960cb53b0c400e81b
- git.kernel.org https://git.kernel.org/stable/c/33163c68d2e3061fa3935b5f0a1867958b1cdbd2
- git.kernel.org https://git.kernel.org/stable/c/4da7fcc098218ff92b2e83a43f545c02f714cedd
- git.kernel.org https://git.kernel.org/stable/c/6bd2569d0b2f918e9581f744df0263caf73ee76c
- git.kernel.org https://git.kernel.org/stable/c/9a350f30d65197354706b7759b5c89d6c267b1a9
- git.kernel.org https://git.kernel.org/stable/c/9ad0452c0277b816a435433cca601304cfac7c21
- git.kernel.org https://git.kernel.org/stable/c/9da3e442714f7f4393ff01c265c4959c03e88c2f
- git.kernel.org https://git.kernel.org/stable/c/cdaa6d1cb2ff1219c6c822b27655dd170ffb0f72
- lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Remediation
- git.kernel.org https://git.kernel.org/stable/c/119766de4930ff40db9f36b960cb53b0c400e81b
- git.kernel.org https://git.kernel.org/stable/c/33163c68d2e3061fa3935b5f0a1867958b1cdbd2
- git.kernel.org https://git.kernel.org/stable/c/4da7fcc098218ff92b2e83a43f545c02f714cedd
- git.kernel.org https://git.kernel.org/stable/c/6bd2569d0b2f918e9581f744df0263caf73ee76c
- git.kernel.org https://git.kernel.org/stable/c/9a350f30d65197354706b7759b5c89d6c267b1a9
- git.kernel.org https://git.kernel.org/stable/c/9ad0452c0277b816a435433cca601304cfac7c21
- git.kernel.org https://git.kernel.org/stable/c/9da3e442714f7f4393ff01c265c4959c03e88c2f
- git.kernel.org https://git.kernel.org/stable/c/cdaa6d1cb2ff1219c6c822b27655dd170ffb0f72