CVE-2026-68436
Vulnerability Scoring
Status: Received on 12 Aug 2026, 00:17 UTC
Published on: 12 Aug 2026, 00:17 UTC
CVSS Release:
CVE-2026-68436: 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 [amdgpu] amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu] dc_create() then returns NULL and DM init fails, which aborts the whole GPU init and makes amdgpu probe fail with -EINVAL ("hw_init of IP block <dm> failed -22"), leaving the display unusable. The subsequent amdgpu_irq_put() warnings during teardown are just fallout of unwinding a half-initialized device. struct dc is a software-only bookkeeping structure that is never handed to hardware DMA and is only ever kept as an opaque pointer, so it does not require physically contiguous memory. Allocate it with kvzalloc() (and free it with kvfree()) so that the allocator can fall back to vmalloc() when a contiguous allocation of that size is not available, which also avoids the MAX_PAGE_ORDER warning entirely. v2: - Rebase to amd-staging-drm-next. (cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)
The exploitability of CVE-2026-68436 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
No exploitability data is available for CVE-2026-68436.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-68436, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-68436, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
Unknown
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