CVE-2026-74525 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
net: sxgbe: free TX rings on RX allocation failure
When RX descriptor ring allocation fails, init_dma_desc_rings() only frees the partially allocated RX rings and returns. The TX rings that were allocated earlier in the same function are leaked.
Rearrange error labels to clean up TX rings upon RX failures.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability exists within the linux kernel's sxgbe network driver implementation where a resource leak occurs during DMA descriptor ring initialization. The issue manifests when the init_dma_desc_rings() function encounters a failure during RX descriptor ring allocation, leaving TX rings that were previously allocated in an unreleased state. This represents a classic memory management error where error handling paths fail to properly clean up resources that were successfully allocated before the failure occurred. The vulnerability directly impacts system stability and resource utilization as leaked memory segments accumulate over time, particularly in high-traffic network environments where driver initialization may occur repeatedly.
The technical flaw stems from improper error handling within the DMA descriptor ring allocation routine. When RX descriptor allocation fails, the function executes cleanup only for the partially allocated RX rings while completely bypassing the cleanup of previously allocated TX rings. This creates a resource leak scenario that violates fundamental memory management principles and can lead to progressive system degradation. The issue is categorized under CWE-404 as improper resource release or unbalanced allocation, specifically manifesting as a failure to properly manage allocated resources during error conditions.
The operational impact of this vulnerability extends beyond simple memory consumption issues to potentially affect network performance and system reliability. In production environments with high network throughput, repeated driver initialization failures could lead to memory exhaustion, causing system instability or even complete system crashes. The leak accumulates over time as the driver repeatedly attempts to initialize DMA rings, with each failure leaving additional TX ring structures unreleased. This can particularly affect systems running multiple network interfaces or those experiencing frequent network configuration changes where driver reinitialization occurs regularly.
Mitigation strategies should focus on implementing proper error handling with comprehensive cleanup routines that ensure all allocated resources are released regardless of which allocation step fails. The solution involves rearranging the error labels and cleanup logic within init_dma_desc_rings() to guarantee that TX rings are freed when RX allocation fails, following established patterns in kernel development for resource management. This aligns with ATT&CK technique T1490 which covers resource exhaustion attacks, as this vulnerability could potentially be exploited to cause system instability through memory consumption. System administrators should monitor memory usage patterns and consider applying kernel updates that address this specific resource leak issue to prevent progressive degradation of network subsystem performance.