CVE-2022-49618 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: aspeed: Fix potential NULL dereference in aspeed_pinmux_set_mux()
pdesc could be null but still dereference pdesc->name and it will lead to a null pointer access. So we move a null check before dereference.
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Analysis
by VulDB Data Team • 02/26/2025
The vulnerability CVE-2022-49618 represents a critical null pointer dereference flaw within the Linux kernel's pinctrl subsystem, specifically affecting the Aspeed pinmux driver implementation. This issue resides in the aspeed_pinmux_set_mux() function where the code attempts to access the pdesc->name member without first validating whether the pdesc pointer itself is null. The flaw demonstrates a classic programming error pattern where developers fail to implement proper null pointer validation before dereferencing pointers, creating a potential system crash or denial of service condition.
The technical nature of this vulnerability aligns with CWE-476, which specifically addresses null pointer dereference conditions in software implementations. The root cause occurs when the function processes pin configuration requests but encounters a scenario where the pin description structure pdesc has not been properly initialized or allocated. This can happen during edge cases in the pinmux configuration process where the driver fails to properly establish the pin description context before attempting to access its members. The vulnerability creates an execution path where the kernel attempts to read from memory address zero or an invalid memory location, leading to immediate system termination or unpredictable behavior.
From an operational perspective, this vulnerability poses significant risks to embedded systems and server platforms that utilize Aspeed chipsets, particularly those implementing the pinctrl framework for hardware pin management. The impact extends beyond simple system crashes as it can affect the entire system stability, potentially allowing attackers to cause persistent denial of service conditions or create opportunities for privilege escalation. Systems relying on the aspeed pinmux driver for GPIO, UART, SPI, and other peripheral pin configurations are particularly vulnerable. The vulnerability is especially concerning in industrial control systems, network appliances, and embedded devices where system reliability is paramount, as a single null pointer dereference can compromise the entire operational environment.
Mitigation strategies for CVE-2022-49618 involve implementing proper null pointer validation before accessing any pointer members, a fundamental defensive programming practice that aligns with the principle of least privilege and robust error handling. The fix requires moving the null check for pdesc before any dereference operations, ensuring that the driver gracefully handles cases where pin description structures are not properly initialized. System administrators should prioritize applying the kernel patches that resolve this issue, particularly in production environments where the affected Aspeed-based systems operate. Additionally, implementing proper runtime monitoring and anomaly detection systems can help identify potential exploitation attempts or system instability caused by this vulnerability. The remediation approach should follow established security best practices including thorough testing of kernel updates, maintaining system integrity through proper patch management protocols, and ensuring that all embedded systems utilizing Aspeed chipsets receive timely security updates to prevent exploitation of this null pointer dereference condition.