CVE-2023-54266

Vulnerability

CVE-2023-54266 is a memory leak vulnerability in the Linux kernel's m920x driver, part of the DVB-USB media subsystem. The flaw resides in the m920x_i2c_xfer() function, which dynamically allocates a buffer read for receiving data. When a call to m920x_read() fails, the error path omits kfree(read), causing the allocated memory to remain unreferenced. The description notes that read is freed only when known to be NULL, but not on read errors, creating a small but persistent leak.

Exploitation

An attacker would need local access to the system (e.g., via a crafted USB device or user-initiated I2C transactions) to trigger the error condition. The vulnerability is not remotely exploitable without prior system access. The leak is triggered only when the underlying hardware or communication fails during an I2C read, making it a low-frequency issue under normal operation.

Impact

A local attacker or malicious USB device could repeatedly induce I2C read failures, causing the kernel to leak small amounts of memory over time. While each leak is only the size of a single buffer, repeated exploitation could exhaust system memory, potentially leading to denial of service. No privilege escalation or data corruption is described.

Mitigation

The official kernel stable tree has fixed this vulnerability in commits 2b6e20ef0585 and c0178e938f11 among others [1][2][3][4]. Users should update their kernel to include the patch. No workaround is available for unpatched systems.