Linux Kernel Bitmap Allocation Size Vulnerability in PowerPC XIVE SPAPR

A vulnerability in the Linux kernel's PowerPC XIVE SPAPR implementation has been identified, related to incorrect bitmap allocation sizes. This flaw was detected by KASAN, which reported a 'slab-out-of-bounds' error. The issue arises because the allocation mistakenly uses bits as the unit, rather than the appropriate size in bytes. As a result, the allocated memory can be smaller than expected, leading to invalid memory accesses. This vulnerability was introduced in version 5.19.0-rc2 and has been addressed in subsequent releases.

Impact

Exploitation of this vulnerability causes a 'slab-out-of-bounds' access, where memory beyond the allocated buffer is read, potentially leading to information disclosure or other memory corruption issues.