CVE-2022-49832 is a vulnerability identified in the Linux kernel's pinctrl subsystem, specifically within the device tree handling code. The flaw arises from a null pointer dereference in the function pinctrl_dt_to_map, which is responsible for mapping pin control configurations from the device tree. The root cause is that the kasprintf() function, which internally calls kmalloc() to allocate memory, can return a NULL pointer if memory allocation fails. The vulnerable code does not properly check for this NULL pointer before using it, leading to a null pointer dereference. This is evidenced by the Kernel Address Sanitizer (KASAN) bug report showing a null pointer dereference in strcmp, which is called during device tree property lookup (__of_find_property and of_find_property). When kasprintf() returns NULL, the code attempts to use this pointer, causing a kernel crash or panic due to the null dereference. The fix involves adding a check for the NULL pointer and returning an ENOMEM error code if memory allocation fails, preventing the kernel from dereferencing a null pointer. The vulnerability affects multiple versions of the Linux kernel identified by the commit hash 57291ce295c0aca738dd284c4a9c591c09ebee71. No known exploits are reported in the wild, and no CVSS score has been assigned yet. This vulnerability is a stability and reliability issue that can lead to denial of service (DoS) conditions by crashing the kernel when processing device tree pinctrl configurations, especially under low-memory conditions.

For European organizations, this vulnerability primarily poses a risk of denial of service on Linux systems that utilize device tree-based pin control configurations, which are common in embedded systems, IoT devices, and some server environments. A kernel crash caused by this null pointer dereference can lead to system downtime, impacting availability of critical services. Organizations relying on Linux-based infrastructure, especially those deploying custom or embedded Linux kernels in industrial control systems, telecommunications, or network equipment, may experience unexpected reboots or service interruptions. While this vulnerability does not directly lead to privilege escalation or data breach, the resulting instability can disrupt operations, cause loss of productivity, and potentially impact safety-critical systems. The lack of known exploits reduces immediate risk, but the vulnerability should be addressed promptly to maintain system reliability and prevent potential exploitation in the future.

European organizations should apply the official Linux kernel patches that address this null pointer dereference as soon as they become available from their Linux distribution vendors or the upstream Linux kernel project. Specifically, ensure that the pinctrl subsystem code includes the NULL pointer check after kasprintf() calls and returns ENOMEM appropriately. For embedded and IoT devices running custom kernels, developers should backport the fix to their kernel versions. Additionally, organizations should implement robust memory monitoring and alerting to detect low-memory conditions that could trigger this vulnerability. Employ kernel crash dump analysis tools to quickly identify and diagnose any kernel panics related to pinctrl device tree processing. Where possible, test kernel updates in staging environments before production deployment to avoid unexpected downtime. Finally, maintain regular system backups and high availability configurations to minimize impact from potential kernel crashes.