CVE-2026-46276
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
In the Linux kernel amdgpu driver, a bug causes a system crash during initialization of RDNA4 GPUs (e.g., RX 9070 XT). The issue occurs when amdgpu_ttm_init_on_chip() calls ttm_range_man_init() with zero size for absent GDS, GWS, and OA resources, triggering a DRM_MM_BUG_ON assertion and kernel panic. The fix adds an early return when size is zero, skipping TTM resource manager registration for non-existent hardware.
Risk Assessment
Organizations using AMD RDNA4 GPUs (RX 9000 series) with CONFIG_DRM_DEBUG_MM enabled in the kernel config will experience an immediate system crash when loading the amdgpu module. This can prevent system boot or disrupt applications relying on graphics acceleration.
Recommendation
Update the Linux kernel to a version containing commit 5719ce5865279cad4fd5f01011fe037168503f2d or later. If an update is not possible, temporarily disable CONFIG_DRM_DEBUG_MM in the kernel configuration.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix zero-size GDS range init on RDNA4 RDNA4 (GFX 12) hardware removes the GDS, GWS, and OA on-chip memory resources. The gfx_v12_0 initialisation code correctly leaves adev->gds.gds_size, adev->gds.gws_size, and adev->gds.oa_size at zero to reflect this. amdgpu_ttm_init() unconditionally calls amdgpu_ttm_init_on_chip() for each of these resources regardless of size. When the size is zero, amdgpu_ttm_init_on_chip() forwards the call to ttm_range_man_init(), which calls drm_mm_init(mm, 0, 0). drm_mm_init() immediately fires DRM_MM_BUG_ON(start + size <= start) -- trivially true when size is zero -- crashing the kernel during modprobe of amdgpu on an RX 9070 XT. Guard against this by returning 0 early from amdgpu_ttm_init_on_chip() when size_in_page is zero. This skips TTM resource manager registration for hardware resources that are absent, without affecting any other GPU type. DRM_MM_BUG_ON() only asserts if CONFIG_DRM_DEBUG_MM is enabled in the kernel config. This is apparently rarely enabled as these chips have been in the market for over a year and this issue was only reported now. Oops-Analysis: http://oops.fenrus.org/reports/bugzilla.korg/221376/report.html (cherry picked from commit 5719ce5865279cad4fd5f01011fe037168503f2d)