In the Linux kernel, the following vulnerability has been resolved:
drm/panthor: Fix handling of partial GPU mapping of BOs
This commit fixes the bug in the handling of partial mapping of the
buffer objects to the GPU, which caused kernel warnings.
Panthor didn't correctly handle the case where the partial mapping
spanned multiple scatterlists and the mapping offset didn't point
to the 1st page of starting scatterlist. The offset variable was
not cleared after reaching the starting scatterlist.
Following warning messages were seen.
WARNING: CPU: 1 PID: 650 at drivers/iommu/io-pgtable-arm.c:659 __arm_lpae_unmap+0x254/0x5a0
pc : __arm_lpae_unmap+0x254/0x5a0
lr : __arm_lpae_unmap+0x2cc/0x5a0
Call trace:
__arm_lpae_unmap+0x254/0x5a0
__arm_lpae_unmap+0x108/0x5a0
__arm_lpae_unmap+0x108/0x5a0
__arm_lpae_unmap+0x108/0x5a0
arm_lpae_unmap_pages+0x80/0xa0
panthor_vm_unmap_pages+0xac/0x1c8 [panthor]
panthor_gpuva_sm_step_unmap+0x4c/0xc8 [panthor]
op_unmap_cb.isra.23.constprop.30+0x54/0x80
__drm_gpuvm_sm_unmap+0x184/0x1c8
drm_gpuvm_sm_unmap+0x40/0x60
panthor_vm_exec_op+0xa8/0x120 [panthor]
panthor_vm_bind_exec_sync_op+0xc4/0xe8 [panthor]
panthor_ioctl_vm_bind+0x10c/0x170 [panthor]
drm_ioctl_kernel+0xbc/0x138
drm_ioctl+0x210/0x4b0
__arm64_sys_ioctl+0xb0/0xf8
invoke_syscall+0x4c/0x110
el0_svc_common.constprop.1+0x98/0xf8
do_el0_svc+0x24/0x38
el0_svc+0x34/0xc8
el0t_64_sync_handler+0xa0/0xc8
el0t_64_sync+0x174/0x178
panthor : [drm] drm_WARN_ON(unmapped_sz != pgsize * pgcount)
WARNING: CPU: 1 PID: 650 at drivers/gpu/drm/panthor/panthor_mmu.c:922 panthor_vm_unmap_pages+0x124/0x1c8 [panthor]
pc : panthor_vm_unmap_pages+0x124/0x1c8 [panthor]
lr : panthor_vm_unmap_pages+0x124/0x1c8 [panthor]
panthor : [drm] *ERROR* failed to unmap range ffffa388f000-ffffa3890000 (requested range ffffa388c000-ffffa3890000)
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-07). 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
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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