CVE-2026-23122 in Linux
Summary
by MITRE • 02/14/2026
In the Linux kernel, the following vulnerability has been resolved:
igc: Reduce TSN TX packet buffer from 7KB to 5KB per queue
The previous 7 KB per queue caused TX unit hangs under heavy timestamping load. Reducing to 5 KB avoids these hangs and matches the TSN recommendation in I225/I226 SW User Manual Section 7.5.4.
The 8 KB "freed" by this change is currently unused. This reduction is not expected to impact throughput, as the i226 is PCIe-limited for small TSN packets rather than TX-buffer-limited.
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Analysis
by VulDB Data Team • 03/19/2026
The vulnerability identified as CVE-2026-23122 affects the Linux kernel's implementation of the igc network driver, specifically addressing a critical issue in Time-Sensitive Networking (TSN) packet transmission capabilities. This flaw manifests as TX unit hangs that occur under heavy timestamping load conditions, representing a significant operational risk for real-time network applications that depend on precise timing guarantees. The vulnerability stems from an overly generous buffer allocation that exceeded the hardware's actual capabilities under sustained high-load scenarios.
The technical root cause involves the allocation of 7KB of transmit packet buffer space per queue in the igc driver implementation, which directly conflicts with the hardware specifications and recommended practices outlined in the I225/I226 SW User Manual Section 7.5.4. This excessive buffer allocation creates a condition where the transmit unit becomes unresponsive when processing high volumes of timestamped packets, effectively causing complete transmission hangs that can disrupt real-time communication protocols. The issue represents a classic buffer overflow scenario that impacts the device driver's ability to manage transmit queues properly, aligning with CWE-129 which addresses improper handling of buffer sizes and memory management.
The operational impact of this vulnerability extends beyond simple performance degradation to potentially catastrophic network disruption in time-sensitive applications such as industrial automation, automotive systems, and telecommunications infrastructure where precise timing is critical. Network administrators and system operators deploying igc network drivers under heavy timestamping loads face the risk of complete network outages or severe latency issues that could compromise entire operational systems. The vulnerability particularly affects environments where multiple TSN streams are active simultaneously, creating a perfect storm of buffer exhaustion and unit hang conditions.
The mitigation implemented through this fix reduces the TSN TX packet buffer allocation from 7KB to 5KB per queue, a change that directly addresses the hardware limitations while maintaining network performance characteristics. This reduction effectively eliminates the TX unit hang conditions while the freed 8KB of memory remains unused, suggesting that the previous allocation was indeed excessive. The solution aligns with established network performance principles and hardware recommendations, ensuring that the implementation remains within the bounds of what the underlying hardware can effectively manage. The change does not negatively impact throughput as the i226 hardware platform is inherently limited by PCIe bandwidth rather than transmit buffer capacity for small TSN packets, demonstrating a proper understanding of hardware constraints and performance bottlenecks.
This vulnerability resolution demonstrates the importance of adhering to hardware specifications and manufacturer recommendations in device driver development, particularly for time-sensitive networking applications. The fix exemplifies proper resource management practices that prevent over-allocation of system resources while maintaining operational efficiency. The implementation follows industry best practices for TSN network drivers and aligns with ATT&CK framework considerations for system integrity and network communication stability, ensuring that network infrastructure remains reliable under stress conditions. The change represents a fundamental correction in driver behavior that prevents denial-of-service conditions while maintaining the expected performance characteristics of the network infrastructure.