CVE-2025-38086

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.

• 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 • debian debian linux 11.0