CVE-2026-68436

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: use kvzalloc to allocate struct dc

struct dc has grown large over time (most of it the two inlined

dc_scratch_space copies) and now sits close to the page allocator's 4 MiB

contiguous allocation limit. Its actual size is not fixed by the source

alone, it also depends on the compiler and the .config, so it can easily

cross 4 MiB, e.g. with a newer GCC or a config change.

dc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the

request is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER,

so the page allocator warns and returns NULL. dc_create() then fails, DM

init fails and amdgpu probe aborts with -EINVAL:

WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380

dc_create+0x38/0x660 [amdgpu]

amdgpu_dm_init+0x2d9/0x510 [amdgpu]

dm_hw_init+0x1b/0x90 [amdgpu]

amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu]

amdgpu_driver_load_kms+0x19/0x80 [a

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References