# CVE-2026-68436: drm/amd/display: use kvzalloc to allocate struct dc CVE-2026-68436 is fixed in 11 products on 1 platform, first by DEBIAN-CVE-2026-68436, released August 13, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-68436 - Priority: Routine - CVSS: 4.1 (Moderate) - EPSS: 0.0016 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 12, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68436 ## 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 [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 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) ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.90.1.150700.17.51.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_24 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-68436](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68436.md) | Aug 13, 2026 | | Linux | linux Debian 14 | 7.1.6-1 | [DEBIAN-CVE-2026-68436](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68436.md) | Aug 13, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.