Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: don’t allow mapping the MMIO HDP page with large pages
We don’t get the right offset in that case. The GPU has an unused 4K area of the register BAR space into which you can remap registers. We remap the HDP flush registers into this space to allow userspace (CPU or GPU) to flush the HDP when it updates VRAM. However, on systems with >4K pages, we end up exposing PAGE_SIZE of MMIO space.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Oracle Linux 7 ELS , Ubuntu 18.04 ELS
- Affected packages:
- linux @ 4.15.0 (+2 more)
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: don’t allow mapping the MMIO HDP page with large pages
We don’t get the right offset in that case. The GPU has an unused 4K area of the register BAR space into which you can remap registers. We remap the HDP flush registers into this space to allow userspace (CPU or GPU) to flush the HDP when it updates VRAM. However, on systems with >4K pages, we end up exposing PAGE_SIZE of MMIO space.