GHSA-VHC7-6HRM-49VV
Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-10 15:33In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix aperture mapping leak
amdgpu_pci_remove() calls drm_dev_unplug() before invoking the driver fini routines. This causes drm_dev_enter() in amdgpu_ttm_fini() to always return false, so iounmap(aper_base_kaddr) never runs on normal driver unload, leaving an orphaned entry in the x86 PAT interval tree.
On connected_to_cpu hardware, the aperture is mapped write-back (WB) via ioremap_cache(). On reload, IP discovery calls memremap(..., MEMREMAP_WC) over the same range. The WC vs WB conflict causes:
ioremap error for 0x..., requested 0x1, got 0x0 amdgpu: discovery failed: -2
Fix by switching to devres-managed mappings so cleanup is guaranteed regardless of drm_dev_enter() state:
-
connected_to_cpu path: devm_memremap(MEMREMAP_WB). For IORESOURCE_SYSTEM_RAM ranges this takes the try_ram_remap() shortcut, returning __va(offset) from the existing kernel direct map. No new ioremap VA or PAT entry is created, so there is nothing to orphan.
-
dGPU path: devm_ioremap_wc() registers iounmap() as a devres action, guaranteeing cleanup at device_del() time.
Also remove iounmap(aper_base_kaddr) from amdgpu_device_unmap_mmio() since the mapping is now devres-owned.
v2: Remove redundant x86_64 guard (Lijo)
(cherry picked from commit d871e99879cb5fd1fa798b006b4888887e63a17a)
{
"affected": [],
"aliases": [
"CVE-2026-68102"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-10T13:19:54Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: fix aperture mapping leak\n\namdgpu_pci_remove() calls drm_dev_unplug() before invoking the driver\nfini routines. This causes drm_dev_enter() in amdgpu_ttm_fini() to\nalways return false, so iounmap(aper_base_kaddr) never runs on normal\ndriver unload, leaving an orphaned entry in the x86 PAT interval tree.\n\nOn connected_to_cpu hardware, the aperture is mapped write-back (WB) via\nioremap_cache(). On reload, IP discovery calls memremap(..., MEMREMAP_WC)\nover the same range. The WC vs WB conflict causes:\n\n ioremap error for 0x..., requested 0x1, got 0x0\n amdgpu: discovery failed: -2\n\nFix by switching to devres-managed mappings so cleanup is guaranteed\nregardless of drm_dev_enter() state:\n\n- connected_to_cpu path: devm_memremap(MEMREMAP_WB). For\n IORESOURCE_SYSTEM_RAM ranges this takes the try_ram_remap() shortcut,\n returning __va(offset) from the existing kernel direct map. No new\n ioremap VA or PAT entry is created, so there is nothing to orphan.\n\n- dGPU path: devm_ioremap_wc() registers iounmap() as a devres action,\n guaranteeing cleanup at device_del() time.\n\nAlso remove iounmap(aper_base_kaddr) from amdgpu_device_unmap_mmio()\nsince the mapping is now devres-owned.\n\nv2: Remove redundant x86_64 guard (Lijo)\n\n(cherry picked from commit d871e99879cb5fd1fa798b006b4888887e63a17a)",
"id": "GHSA-vhc7-6hrm-49vv",
"modified": "2026-08-10T15:33:35Z",
"published": "2026-08-10T15:33:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68102"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6405c4e75b3bcf0e72bd7a0ff5f1ed0c475e23aa"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/67bc3647e418e23dc0d17604bdba634a73de809f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a343d028ad6c174da8dc6af560c51e6d140a6727"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ea772a440d56b285f4d491affac50ecd41f6b402"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f5988b5c300a32ff751724ffd33d5a8d5873e4a7"
}
],
"schema_version": "1.4.0",
"severity": []
}
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