CVE-2023-54266 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
media: dvb-usb: m920x: Fix a potential memory leak in m920x_i2c_xfer()
'read' is freed when it is known to be NULL, but not when a read error occurs.
Revert the logic to avoid a small leak, should a m920x_read() call fail.
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Analysis
by VulDB Data Team • 04/27/2026
The vulnerability CVE-2023-54266 represents a memory leak in the Linux kernel's DVB (Digital Video Broadcasting) USB subsystem, specifically within the m920x driver implementation. This flaw exists in the media subsystem's dvb-usb framework where the m920x_i2c_xfer() function fails to properly handle memory deallocation when read operations encounter errors. The issue stems from improper resource management where the read buffer is correctly freed only when it is explicitly NULL, but remains allocated when read errors occur during m920x_read() calls, creating a small but persistent memory leak within the kernel's USB media handling infrastructure.
The technical implementation flaw occurs within the m920x_i2c_xfer() function where memory allocation for read operations is not consistently managed across all execution paths. When m920x_read() encounters an error condition, the function does not properly free the allocated read buffer, leading to memory that remains allocated but unreferenced. This type of memory leak represents a classic resource management vulnerability that can accumulate over time, particularly in systems with frequent USB device interactions or continuous media streaming operations. The vulnerability specifically affects the m920x driver which is used for various USB DVB receivers, making it relevant to a broad range of media processing systems that rely on kernel-level USB communication.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as it can contribute to system performance degradation and potential resource exhaustion in long-running systems. While the leak is described as "small," in environments with high-frequency USB device operations or extended system uptime, accumulated memory leaks can lead to increased memory pressure, reduced system responsiveness, and potential system instability. The vulnerability affects systems running Linux kernels with the affected DVB USB drivers, particularly those implementing the m920x chipset for USB-based digital television reception. This type of vulnerability is especially concerning in embedded systems or media servers where continuous operation and resource efficiency are critical for maintaining service availability and performance.
Mitigation strategies for CVE-2023-54266 involve applying the kernel patch that reverts the problematic logic to ensure proper memory deallocation in all error conditions. System administrators should prioritize updating to kernel versions that include the fix, typically those containing the corrected m920x_i2c_xfer() implementation. The fix addresses the root cause by ensuring that read buffers are properly freed regardless of whether m920x_read() operations succeed or fail, thereby preventing the accumulation of leaked memory. Organizations should also implement monitoring for memory usage patterns in systems utilizing affected USB DVB receivers, as this vulnerability can contribute to gradual memory consumption that may not be immediately apparent. The fix aligns with security best practices for kernel memory management and represents a standard defensive programming approach that prevents resource leaks through proper error handling and resource cleanup mechanisms. This vulnerability classification aligns with CWE-401: Improper Release of Memory and can be mapped to ATT&CK technique T1490: Inhibit System Recovery through memory exhaustion attacks that could potentially leverage such resource leaks.