CVE-2024-26978 in Linux
Summary
by MITRE • 05/01/2024
In the Linux kernel, the following vulnerability has been resolved:
serial: max310x: fix NULL pointer dereference in I2C instantiation
When trying to instantiate a max14830 device from userspace:
echo max14830 0x60 > /sys/bus/i2c/devices/i2c-2/new_device
we get the following error:
Unable to handle kernel NULL pointer dereference at virtual address... ... Call trace: max310x_i2c_probe+0x48/0x170 [max310x]
i2c_device_probe+0x150/0x2a0 ...
Add check for validity of devtype to prevent the error, and abort probe with a meaningful error message.
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Analysis
by VulDB Data Team • 02/06/2026
The vulnerability CVE-2024-26978 represents a critical null pointer dereference flaw within the Linux kernel's max310x serial driver implementation, specifically affecting I2C device instantiation processes. This issue manifests when userspace attempts to create a new max14830 device instance through the I2C bus interface, triggering a kernel panic due to improper validation of device type parameters during the probe phase. The vulnerability resides in the kernel's serial communication subsystem where the max310x driver fails to validate device type information before proceeding with device initialization, creating a path for null pointer access that can lead to system instability and potential denial of service conditions.
The technical root cause stems from inadequate input validation within the max310x_i2c_probe function where the driver does not properly verify the validity of the device type parameter before attempting to dereference it. This flaw directly maps to CWE-476 which describes null pointer dereference vulnerabilities, and aligns with ATT&CK technique T1068 which involves exploitation of privilege escalation vulnerabilities through kernel-level flaws. When the I2C bus subsystem receives the device creation command through the sysfs interface, the driver's probe routine fails to check whether the device type structure is properly initialized, leading to immediate kernel panic upon attempting to access uninitialized memory locations. The call trace clearly demonstrates the execution path leading to the null pointer dereference originating from the max310x_i2c_probe function which is responsible for initializing I2C serial device instances.
The operational impact of this vulnerability extends beyond simple system crashes, as it can compromise the stability of embedded systems and industrial control environments where serial communication is critical. Attackers could potentially exploit this vulnerability to cause denial of service conditions, particularly in environments where automated device provisioning occurs through I2C bus interfaces. The vulnerability affects systems running Linux kernels that include the max310x driver, making it relevant to a wide range of embedded devices, industrial automation systems, and IoT platforms that utilize serial communication protocols. Systems utilizing the max14830 device type specifically face risk when userspace applications attempt device instantiation through the I2c bus interface, as the kernel's response to such operations could result in complete system hang or reboot conditions.
Mitigation strategies for this vulnerability require immediate kernel updates addressing the null pointer dereference issue through proper device type validation before memory access operations. The fix implemented in the patched kernel version involves adding explicit validation checks for device type parameters within the probe function, ensuring that the driver gracefully handles invalid device type information by returning appropriate error codes rather than attempting to dereference null pointers. System administrators should prioritize kernel updates and patch management processes to address this vulnerability across all affected Linux installations, particularly in production environments where serial communication stability is paramount. Additionally, monitoring for unusual I2C device instantiation attempts and implementing proper input validation at the userspace level can provide additional defensive measures against exploitation of this class of vulnerability, aligning with security best practices outlined in NIST SP 800-128 for kernel-level vulnerability management and remediation.