CVE-2022-48703 is a vulnerability identified in the Linux kernel's thermal management subsystem, specifically within the int340x_thermal driver. The issue arises when the Generic Dynamic Data Vault (GDDV) returns a package containing a buffer with zero length. In this scenario, the kernel function kmemdup() returns a special pointer value ZERO_SIZE_PTR (0x10) instead of a typical NULL pointer. The vulnerable function data_vault_read() does not properly check for this ZERO_SIZE_PTR value and attempts to dereference it as if it were a valid pointer. This results in a NULL pointer dereference at address 0x10, causing a kernel BUG and likely a system crash (kernel panic). The root cause is the lack of proper validation for zero-length buffers returned by GDDV, leading to unsafe memory access. The patch for this vulnerability involves using the ZERO_OR_NULL_PTR() macro to correctly check for both NULL and ZERO_SIZE_PTR values before dereferencing the pointer, thereby preventing the NULL pointer dereference. This vulnerability affects Linux kernel versions identified by the given commit hashes, and it was publicly disclosed on May 3, 2024. There are no known exploits in the wild at the time of disclosure, and no CVSS score has been assigned yet.

For European organizations running Linux systems with the affected kernel versions, this vulnerability poses a risk of denial of service (DoS) due to kernel crashes triggered by the NULL pointer dereference. Systems relying on the int340x_thermal driver, which is typically used for thermal management on certain Intel-based platforms, could experience unexpected reboots or downtime. This can disrupt critical services, especially in environments where uptime and reliability are paramount, such as data centers, industrial control systems, and cloud infrastructure. Although this vulnerability does not appear to allow privilege escalation or remote code execution directly, the resulting system instability could be exploited by attackers to cause service interruptions or to facilitate further attacks by forcing system reboots. The absence of known exploits reduces immediate risk, but the vulnerability's presence in the widely deployed Linux kernel means that unpatched systems remain vulnerable to accidental or malicious triggering of the bug.

European organizations should promptly identify Linux systems running the affected kernel versions, especially those using Intel platforms with the int340x_thermal driver. Applying the official Linux kernel patch that introduces the ZERO_OR_NULL_PTR() check is the primary mitigation step. If immediate patching is not feasible, organizations should monitor system logs for kernel BUG messages referencing NULL pointer dereferences at address 0x10 and consider temporarily disabling or blacklisting the int340x_thermal driver if it is not critical to system operation. Additionally, implementing kernel crash monitoring and automated reboot prevention mechanisms can help reduce downtime. Organizations should also ensure that their incident response teams are aware of this vulnerability to quickly diagnose and respond to related system crashes. Finally, maintaining up-to-date kernel versions and subscribing to Linux kernel security advisories will help mitigate similar vulnerabilities in the future.