CVE-2026-68091 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
HID: wacom: stop hardware after post-start probe failures
wacom_parse_and_register() starts HID hardware before registering inputs and initializing pad LEDs/remotes. Those later steps can fail, but their error paths currently release Wacom resources without stopping the HID hardware.
Route post-hid_hw_start() failures through hid_hw_stop() before releasing driver resources.
This issue was identified during our ongoing static-analysis research while reviewing kernel code.
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Analysis
by VulDB Data Team • 08/10/2026
The vulnerability under discussion relates to a critical flaw in the Linux kernel's HID wacom driver implementation that could potentially lead to hardware resource mismanagement and system instability. This issue specifically affects the wacom_parse_and_register() function which handles the initialization process for Wacom tablet devices through the Human Interface Device subsystem. The problem manifests when the hardware initialization sequence begins before all subsequent setup steps complete successfully, creating a scenario where hardware resources may remain in an inconsistent state if later initialization phases fail.
The technical flaw occurs due to improper error handling within the device probe sequence where HID hardware is started before input registration and LED/remote initialization. When these later steps encounter failures, the current implementation releases driver resources but fails to properly shut down the HID hardware component through the appropriate cleanup mechanism. This creates a state where the hardware remains active while the driver believes it has been properly uninitialized, potentially leading to resource leaks or conflicts with subsequent device operations.
From an operational impact perspective, this vulnerability could result in persistent hardware access issues, driver instability, and potential system crashes when Wacom devices are connected or reconnected to systems running affected kernel versions. The failure to properly stop HID hardware after post-start probe failures creates a resource management gap that may manifest as device unresponsiveness, incorrect input handling, or even broader system stability concerns during device enumeration processes. Attackers could potentially exploit this timing issue to cause persistent device state corruption or denial of service conditions.
The fix implemented addresses this by ensuring proper error routing through hid_hw_stop() before releasing driver resources when post-hid_hw_start() failures occur. This change follows established kernel development practices for resource management and aligns with the common security principle of proper cleanup ordering in error conditions. The vulnerability is classified as a resource management issue that could be categorized under CWE-459, which deals with incomplete cleanup, and potentially relates to CWE-754, dealing with weakness in design for improper handling of error conditions.
This fix demonstrates the importance of proper resource lifecycle management in kernel drivers and reinforces the principle that hardware components must be properly stopped and released before driver resources are freed. The solution follows the ATT&CK framework's concept of privilege escalation through resource manipulation by ensuring that device hardware states are properly managed regardless of initialization success or failure conditions, thereby preventing potential exploitation scenarios where improper state management could lead to persistent access issues or system instability. The static analysis approach used to identify this vulnerability reflects modern security research methodologies that focus on code review and formal verification techniques to discover subtle resource management flaws in kernel subsystems.
The resolution represents a defensive programming improvement that ensures proper error handling boundaries are maintained throughout the device initialization process, preventing hardware state inconsistencies that could be leveraged by malicious actors or simply cause operational problems in legitimate use cases. This type of vulnerability highlights the complexity of kernel-level device drivers where multiple subsystems must coordinate properly during initialization and error recovery scenarios to maintain system stability and security guarantees.