CVE-2026-63906 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
usb: musb: omap2430: Fix use-after-free in omap2430_probe()
In omap2430_probe(), of_node_put(np) is called prematurely before the last access to np, leading to a use-after-free if the node's reference count drops to zero. Move the of_node_put() calls after the last use of np in both the success and error paths.
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Analysis
by VulDB Data Team • 07/19/2026
The vulnerability resides within the Linux kernel's USB subsystem specifically in the musb driver implementation for omap2430 hardware platforms. This represents a classic use-after-free condition that occurs during device probe operations when the kernel attempts to manage device tree node references. The flaw manifests in the omap2430_probe() function where improper reference counting leads to memory safety violations. The issue stems from calling of_node_put(np) before all accesses to the device tree node np have completed, creating a scenario where subsequent code attempts to dereference a freed memory location.
The technical implementation flaw involves incorrect ordering of reference counting operations within the driver's probe routine. When the kernel processes USB device initialization for omap2430 platforms, it must properly manage device tree node references through the standard of_node_put() and of_node_get() functions. In this case, the premature release of the node reference causes the kernel to invalidate memory that subsequent code paths still intends to access. This creates a race condition where memory deallocation occurs before all potential consumers have finished processing the node data.
Operationally, this vulnerability presents significant security implications for embedded systems running Linux kernels with omap2430 USB controllers. An attacker could potentially exploit this use-after-free condition to execute arbitrary code or cause system instability through carefully crafted device tree configurations during system boot. The impact extends beyond simple denial of service as the memory corruption could be leveraged for privilege escalation or information disclosure attacks, particularly in environments where kernel memory layout is predictable. Systems using OMAP2430-based USB controllers are particularly vulnerable as they represent a specific class of embedded hardware that follows this problematic code pattern.
The fix implements proper reference counting by repositioning of_node_put() calls to occur only after the final access to the device tree node np in both successful execution and error handling paths. This aligns with established kernel development practices for managing device tree references and prevents the premature deallocation that leads to use-after-free conditions. The solution follows CWE-416 which catalogs improper free vulnerabilities, and addresses techniques described in ATT&CK matrix under privilege escalation and denial of service tactics. This remediation ensures that all code paths properly maintain reference counts before releasing memory resources, thereby preventing the memory safety violation that could otherwise be exploited by malicious actors.