CVE-2026-98663 in Linux
Summary
by MITRE • 10/18/2026
In the Linux kernel, the following vulnerability has been resolved:
iio: imu: adis16480: fix unprotected debugfs reads
The firmware_revision and firmware_date file operations are open coded and never call debugfs_file_get(), which debugfs_create_file_unsafe() requires. debugfs_remove_recursive() therefore does not wait for a read in progress, and unbind frees the iio_dev underneath it.
Use debugfs_create_file() instead.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/19/2026
The Linux kernel driver for the Analog Devices ADIS16480 inertial measurement unit contains a critical race condition vulnerability within its debug filesystem interface. This issue stems from an improper implementation of file operations that expose internal device structures to user space without adequate synchronization mechanisms. Specifically, the firmware_revision and firmware_date attributes are implemented using open-coded logic that bypasses standard kernel safety checks. The core technical flaw lies in the failure to invoke debugfs_file_get() during file opening operations. This function is a mandatory requirement when utilizing debugfs_create_file_unsafe(), as it serves to increment reference counts on the underlying device structure, ensuring its lifetime extends beyond the duration of the user space access attempt.
Without this protective call, there exists no mechanism to prevent the driver from being unloaded or unbound while a read operation is still in progress by a privileged process. When debugfs_remove_recursive() is executed during device removal, it does not wait for any pending reads to complete because the reference counting logic was omitted. Consequently, if a user space application has an open file descriptor and is actively reading from these attributes at the moment of unbind, the kernel will free the iio_dev structure associated with the device while that memory region remains in use by the ongoing read operation. This scenario creates a classic Use-After-Free condition where the kernel attempts to access freed memory, leading to potential data corruption or system instability.
The operational impact of this vulnerability is severe for systems relying on debugfs interfaces during development or diagnostics phases. Although debugfs is typically mounted with root-only permissions and intended primarily for debugging purposes, an attacker with local root access can exploit this race condition to trigger a kernel panic or cause undefined behavior by manipulating the timing between file reads and device unbinding events. This effectively allows a privileged user to crash the system or potentially escalate privileges if the memory reuse patterns allow for arbitrary code execution through heap corruption techniques. The vulnerability highlights the risks associated with using unsafe debugfs creation functions without adhering strictly to their required synchronization protocols, undermining the stability guarantees provided by the kernel's object lifetime management subsystems.
To mitigate this risk, developers must replace the use of debugfs_create_file_unsafe() with the standard debugfs_create_file() function for these specific attributes. The standard variant automatically handles reference counting and ensures that device structures remain valid throughout the entire duration of user space access. This change aligns the driver implementation with established kernel coding standards and prevents premature memory deallocation during active I/O operations. Furthermore, this fix reinforces adherence to CWE-416, which addresses Use After Free vulnerabilities resulting from improper resource management. From a threat modeling perspective, such race conditions in debug interfaces can be mapped to ATT&CK techniques involving local privilege escalation or denial of service via kernel exploitation, emphasizing the need for rigorous validation of file operation callbacks even within non-production debugging tools.