Linux Kernel Subtraction Overflow Vulnerability in drm/i915 Selftests

A subtraction overflow vulnerability has been identified in the Linux kernel's drm/i915 selftests. This issue arises on certain machines where the variable hole_end can be small enough to trigger a subtraction overflow. Conversely, in mock tests, the expression (addr + 2 * min_alignment) can also overflow. The vulnerability has been addressed in a patch that accommodates both scenarios.

Impact

Exploitation of this vulnerability could lead to a subtraction overflow, potentially causing undefined behavior or allowing for memory corruption.