In the Linux kernel, the following vulnerability has been resolved: s390/debug: Fix NULL pointer dereference in debug_info_copy() When… (CVE-2026-98593)

The vulnerability in the Linux kernel affects the s390/debug subsystem. When debug_register_static() fails, it clears the pointers active_pages and active_entries but does not update the area bounds. Subsequent operations that copy these areas, such as opening the view file or invoking debug_dump(), cause debug_info_copy() to dereference NULL pointers, leading to a potential crash or denial of service. The fix involves skipping the copy loop when the source has no areas, preventing the NULL pointer dereference.

This vulnerability can cause the Linux kernel on s390 architectures to dereference NULL pointers during debug operations, potentially leading to kernel crashes or denial of service conditions. There is no indication of code execution or privilege escalation from the provided data.

A fix has been implemented to skip the copy loop when the source has no areas, preventing the NULL pointer dereference. Users should apply the official Linux kernel patch that resolves this issue. Since no vendor advisory or patch link is provided, check the official Linux kernel repositories or security advisories for the patch and update accordingly.