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CVE-2026-46276 Linux CVE debrief

A vulnerability was discovered in the Linux kernel related to the initialization of zero-size GDS range on RDNA4 hardware. The RDNA4 (GFX 12) hardware removes the GDS, GWS, and OA on-chip memory resources. However, the gfx_v12_0 initialization code correctly sets the sizes of these resources to zero to reflect this. The issue arises when amdgpu_ttm_init() unconditionally calls amdgpu_ttm_init_on_chip() for each of these resources, regardless of their size. When the size is zero, amdgpu_ttm_init_on_chip() calls ttm_range_man_init(), which in turn calls drm_mm_init(mm, 0, 0). This leads to a crash during the modprobe of amdgpu on an RX 9070 XT due to a DRM_MM_BUG_ON() assertion. To fix this, a check was added to return 0 early from amdgpu_ttm_init_on_chip() when the size is zero, preventing the registration of TTM resource managers for absent hardware resources.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-08
Original CVE updated
2026-07-23
Advisory published
2026-06-08
Advisory updated
2026-07-23

Who should care

Users of Linux kernel with RDNA4 hardware, specifically those with AMD GPUs like the RX 9070 XT.

Technical summary

The vulnerability is caused by the unconditional call to amdgpu_ttm_init_on_chip() for GDS, GWS, and OA resources, even when their sizes are zero. This leads to a crash due to a DRM_MM_BUG_ON() assertion. The fix involves adding a check to return early from amdgpu_ttm_init_on_chip() when the size is zero.

Defensive priority

Medium

Recommended defensive actions

  • Update the Linux kernel to a version that includes the fix for CVE-2026-46276.
  • Use resourceLinkAnnotations for more information: {cve-org} and {nvd}.

Evidence notes

The CVE record and NVD detail can be found at {cve-org} and {nvd}, respectively.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-46276 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-46276

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-46276 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-46276

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/095a8b0ad3c3b5cdc3850d961adb8a8f735220bb

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/0e21db1a77967bc15df662efdca8ea8a61d124ea

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/1f5d33e7b0a9a2a140f46e22fb52eede323c5946

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/30c000a49094ec568c9b51b7421f7a4a3f0b0298

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/36f9602fb22ede69fcc8b422be0cf8105bf655ad

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/3e26c76891ab99fa173e9c501119fbb5c9f4600f

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/9bc925759c05feae7dfa9570e77131d54729c8ea

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.