In the Linux kernel, the following vulnerability has been resolved: s390/uv: Prevent potential out-of-bounds read When the system has more than 85… (CVE-2026-98648)

The Linux kernel s390/uv subsystem contained a vulnerability where an out-of-bounds read could occur in the find_secret_in_page function if the system had more than 85 secrets. The uv_secret_list struct array is limited to 85 items per page, but the code erroneously iterated over the total number of secrets instead of the number stored per sub-list, potentially reading beyond the array bounds. The fix involves adjusting the loop to iterate only over the number of stored secrets per sub-list, preventing out-of-bounds access.

An out-of-bounds read vulnerability can lead to information disclosure or system instability depending on how the invalid memory is accessed. However, no known exploits in the wild have been reported for this issue. The impact is limited to systems using the s390/uv subsystem with more than 85 secrets stored.

A fix for this vulnerability has been implemented in the Linux kernel. Users should apply the official kernel updates that include this correction. No additional mitigation steps are indicated.