CVE-2026-74326 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7921: fix resource leak in probe error path
When pcim_iomap_region() or devm_kmemdup() fail, the code returns directly without cleaning up previously allocated resources: - mt76_device allocated by mt76_alloc_device() - pci irq vectors allocated by pci_alloc_irq_vectors() Fix this by jumping to the existing error cleanup path instead of returning directly.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability resides in the linux kernel's wireless subsystem specifically within the mt7921 driver implementation formediate-speed wireless networking devices. The issue represents a classic resource management flaw that occurs during device probe operations when hardware initialization fails. When either pcim_iomap_region() or devm_kmemdup() functions encounter errors during execution, the code path executes a direct return statement instead of properly cleaning up previously allocated system resources. This behavior creates a resource leak condition that can accumulate over time and potentially lead to system instability or denial of service scenarios.
The technical flaw manifests as a failure to follow proper error handling protocols within the device initialization sequence. Specifically, the mt76_device structure allocated through mt76_alloc_device() and pci irq vectors obtained via pci_alloc_irq_vectors() remain allocated in memory even when subsequent initialization steps fail. This direct return pattern violates established kernel programming practices and creates persistent resource consumption that can degrade system performance over extended periods. The vulnerability directly correlates to CWE-404, which addresses improper resource management and failure to release resources, and aligns with ATT&CK technique T1499.004 related to resource exhaustion attacks.
The operational impact of this vulnerability extends beyond simple memory leaks to potentially compromise system reliability and availability. As wireless network devices are frequently initialized and reinitialized during system operation, the accumulation of leaked resources can lead to progressive performance degradation or complete system resource exhaustion. Network administrators may observe increasing memory consumption or intermittent connectivity issues that correlate with device probe operations. In high-availability environments where wireless networking is critical, this vulnerability could contribute to service disruptions or require frequent system reboots to clear accumulated leaks.
Mitigation strategies should focus on implementing proper error handling patterns that follow established kernel development practices and ensure all allocated resources are properly released during error conditions. The fix requires modifying the code to jump to existing error cleanup paths rather than returning directly from failure scenarios, which ensures that mt76_device structures and pci irq vectors are properly deallocated through their respective cleanup functions. System administrators should prioritize applying the relevant kernel updates that contain this fix, particularly in environments where wireless networking is actively used or where resource exhaustion could impact critical operations. Additionally, monitoring systems should track memory usage patterns to identify potential resource leak accumulation before it leads to operational issues.