Bug 2420421 (CVE-2025-40339)

Summary: CVE-2025-40339 kernel: drm/amdgpu: fix nullptr err of vm_handle_moved
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A NULL pointer dereference flaw was found in the Linux kernel's AMD GPU (amdgpu) driver. In the amdgpu_vm_handle_moved() function, when processing amdgpu_bo_va entries that are part of fpriv->prt_va (partially resident texture virtual address), the associated buffer object (bo) is always NULL. Dereferencing this NULL pointer causes a kernel crash. A local user with access to AMD GPU resources could trigger this condition, resulting in a denial of service.
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Description OSIDB Bzimport 2025-12-09 05:02:15 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: fix nullptr err of vm_handle_moved

If a amdgpu_bo_va is fpriv->prt_va, the bo of this one is always NULL.
So, such kind of amdgpu_bo_va should be updated separately before
amdgpu_vm_handle_moved.
Comment 1 Alexander B 2025-12-09 13:08:51 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025120911-CVE-2025-40339-82ee@gregkh/T