Bug 2513146 (CVE-2026-68234)

Summary: CVE-2026-68234 kernel: drm/amdgpu: fix bo->pin leaking in amdgpu_bo_create_reserved
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `drm/amdgpu` component. The `amdgpu_bo_create_reserved` function unconditionally increments a pin counter for a Buffer Object (BO) even if it is already pinned. This occurs when the function is called multiple times with the same BO, such as during firmware buffer re-loading. As a result, the pin count never drops to zero, preventing the Translation Table Manager (TTM) from properly managing memory. This leads to memory leaks and can cause a Denial of Service (DoS) due to resource exhaustion.
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Description OSIDB Bzimport 2026-08-10 12:21:44 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: fix bo->pin leaking in amdgpu_bo_create_reserved

amdgpu_bo_create_reserved() only allocates a new BO when
*bo_ptr (struct amdgpu_bo **bo_ptr as input parameter) is
NULL, it simply skips creation when *bo_ptr is non-NULL.
But it unconditionally reserves, pins, gart allocates
and maps the BO afterwards.

When the same non-NULL BO pointer is passed in again,
for example firmware buffers that live in adev and are
re-loaded on every resume / cp_resume / start
under AMDGPU_FW_LOAD_DIRECT, amdgpu_bo_pin() just increases
pin_count unconditionally, however the matching teardown only unpins
once, so pin_count never drops to zero, so TTM is not able
to move, swap or evict a BO, causing BO leaks.

This commit fixes this issue by only pinning the bo
once at creation, and repeated calls no longer
take additional pin references.

(cherry picked from commit 3ddc0ae76202c447b6aec61e907b852bc94671cf)
Comment 1 gkamathe 2026-08-11 10:54:00 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081017-CVE-2026-68234-c71a@gregkh/T