In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Avoid double-unpin of DOORBELL/MMIO BOs on free
amdgpu_amdkfd_gpuvm_free_memory_of_gpu() unpinned DOORBELL and MMIO
remap BOs (which are pinned at allocation time) before checking whether
the BO is still mapped to the GPU. When the BO is still mapped, the
function returns -EBUSY and leaves the BO alive, but it has already
been unpinned. The BO is then unpinned again when it is finally freed
during process teardown, triggering a ttm_bo_unpin() underflow warning:
WARNING: CPU: 18 PID: 15066 at ttm/ttm_bo.c:650 amdttm_bo_unpin+0x6d/0x80 [amdttm]
Workqueue: kfd_process_wq kfd_process_wq_release [amdgpu]
RIP: 0010:amdttm_bo_unpin+0x6d/0x80 [amdttm]
Call Trace:
amdgpu_bo_unpin+0x1a/0x90 [amdgpu]
amdgpu_amdkfd_gpuvm_unpin_bo+0x31/0xb0 [amdgpu]
amdgpu_amdkfd_gpuvm_free_memory_of_gpu+0x3bf/0x460 [amdgpu]
kfd_process_free_outstanding_kfd_bos+0xd4/0x170 [amdgpu]
kfd_process_wq_release+0x109/0x1b0 [amdgpu]
process_one_work+0x1e2/0x3b0
worker_thread+0x50/0x3a0
kthread+0xdd/0x100
ret_from_fork+0x29/0x50
Move the unpin after the mapped_to_gpu_memory check so it only happens
once we are committed to freeing the BO.
(cherry picked from commit 927c5b2defb9b09856444d94bebfd056a002bd75)
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the BOD 26-04 block below.
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it