CVE-2026-68395 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
ata: sata_dwc_460ex: enable SATA interrupts only after IRQ handler is registered
sata_dwc_enable_interrupts() is called before platform_get_irq() and ata_host_activate(), leaving the SATA controller's interrupt mask enabled without a registered handler. If a later step fails (irq request, phy init, etc.) or if the controller asserts an interrupt during probe, the irq line may fire with no handler, causing a spurious interrupt storm.
Move sata_dwc_enable_interrupts() after ata_host_activate() so that interrupts are only unmasked once the handler is registered and the core is fully initialized.
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Analysis
by VulDB Data Team • 08/10/2026
This vulnerability exists in the linux kernel's sata_dwc_460ex driver where improper ordering of interrupt initialization leads to a race condition during device probe operations. The flaw occurs when sata_dwc_enable_interrupts() function is invoked before platform_get_irq() and ata_host_activate() calls, creating a scenario where the SATA controller's interrupt mask becomes enabled without an associated interrupt handler being registered in the kernel's interrupt subsystem. This fundamental timing issue represents a classic violation of proper device initialization sequences and can be categorized under CWE-691 as insufficient control flow management during hardware initialization.
The operational impact of this vulnerability manifests as a spurious interrupt storm condition where the interrupt line fires repeatedly without any handler to process the interrupts, leading to system instability and potential denial of service conditions. When the controller asserts an interrupt during the probe phase, the kernel receives interrupt signals but has no registered handler to process them, causing continuous interrupt generation that can overwhelm system resources and potentially crash the kernel. This type of vulnerability directly maps to ATT&CK technique T1489 which involves system shutdown or reboot through manipulation of system services, and T1070 which covers indicator removal on host systems.
The root cause stems from improper sequence management in the driver's probe function where interrupt enablement occurs before all necessary initialization steps are completed. The fix implemented moves sata_dwc_enable_interrupts() to execute after ata_host_activate(), ensuring that interrupts are only unmasked once the interrupt handler is properly registered and the core subsystem is fully initialized. This approach follows the established principle of "defer interrupt enabling until after handler registration" which is a fundamental best practice in embedded driver development and aligns with PCI device initialization standards where interrupt setup should occur after all device state is properly configured.
The vulnerability demonstrates how seemingly minor timing issues in kernel drivers can result in significant system reliability problems, particularly in embedded systems where hardware interrupts are frequently used for device communication. The fix addresses the core issue by ensuring proper dependency ordering and preventing premature interrupt enablement that could lead to unhandled interrupt storms. This type of vulnerability is commonly encountered in complex embedded systems where multiple initialization steps must occur in precise sequence to prevent race conditions and resource conflicts, making it particularly relevant to automotive, industrial control, and networking applications that rely heavily on SATA controller functionality.
Security implications extend beyond simple system stability concerns as this vulnerability could potentially be exploited by malicious actors to cause system crashes or to mask other underlying issues within the storage subsystem. The interrupt storm condition created by this flaw can make debugging difficult and may obscure other security-related problems in the system's device management layer. Modern kernel development practices emphasize proper initialization sequencing and interrupt handling as part of secure coding standards, with this particular issue representing a failure to maintain these fundamental principles during driver development. The solution reinforces proper kernel module development patterns that ensure all system resources are properly established before enabling potentially disruptive hardware features like interrupts, thereby preventing both immediate operational failures and potential security exploitation vectors.