The vulnerability in the Linux kernel affects the ACPI APEI GHES error handling code for ARM architectures. Specifically, in the function ghes_handle_arm_hw_error(), the code incorrectly reduces the remaining length after skipping the cper_sec_proc_arm header by the size of a pointer instead of the size of the structure pointed to. This miscalculation leads to an overestimation of bytes left for cper_arm_err_info records, potentially allowing the parser to read past the CPER section boundary when the err_info_num is large relative to error_data_length. The fix involves using sizeof(*err) to correctly account for the structure size, aligning length accounting with pointer advancement and prior size checks.

If exploited, this vulnerability could cause the kernel's error parser to read beyond the intended memory bounds, potentially leading to memory corruption or information disclosure. However, no known exploits are reported in the wild. The impact is limited to ARM platforms using the affected ACPI error handling code.

A fix has been implemented in the Linux kernel source code to correct the length accounting in the affected function. Users should apply the official kernel updates that include this fix once available. Since this is a kernel-level issue, updating to a patched kernel version is the recommended remediation. Patch status is not explicitly confirmed in the provided data; check the vendor advisory or Linux kernel mailing lists for the official patch and update guidance.