In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix WARN_ON in iommu probe path
Commit 1a75cc710b95 ("iommu/vt-d: Use rbtree to track iommu probed
devices") adds all devices probed by the iommu driver in a rbtree
indexed by the source ID of each device. It assumes that each device
has a unique source ID. This assumption is incorrect and the VT-d
spec doesn't state this requirement either.
The reason for using a rbtree to track devices is to look up the device
with PCI bus and devfunc in the paths of handling ATS invalidation time
out error and the PRI I/O page faults. Both are PCI ATS feature related.
Only track the devices that have PCI ATS capabilities in the rbtree to
avoid unnecessary WARN_ON in the iommu probe path. Otherwise, on some
platforms below kernel splat will be displayed and the iommu probe results
in failure.
WARNING: CPU: 3 PID: 166 at drivers/iommu/intel/iommu.c:158 intel_iommu_probe_device+0x319/0xd90
Call Trace:
? __warn+0x7e/0x180
? intel_iommu_probe_device+0x319/0xd90
? report_bug+0x1f8/0x200
? handle_bug+0x3c/0x70
? exc_invalid_op+0x18/0x70
? asm_exc_invalid_op+0x1a/0x20
? intel_iommu_probe_device+0x319/0xd90
? debug_mutex_init+0x37/0x50
__iommu_probe_device+0xf2/0x4f0
iommu_probe_device+0x22/0x70
iommu_bus_notifier+0x1e/0x40
notifier_call_chain+0x46/0x150
blocking_notifier_call_chain+0x42/0x60
bus_notify+0x2f/0x50
device_add+0x5ed/0x7e0
platform_device_add+0xf5/0x240
mfd_add_devices+0x3f9/0x500
? preempt_count_add+0x4c/0xa0
? up_write+0xa2/0x1b0
? __debugfs_create_file+0xe3/0x150
intel_lpss_probe+0x49f/0x5b0
? pci_conf1_write+0xa3/0xf0
intel_lpss_pci_probe+0xcf/0x110 [intel_lpss_pci]
pci_device_probe+0x95/0x120
really_probe+0xd9/0x370
? __pfx___driver_attach+0x10/0x10
__driver_probe_device+0x73/0x150
driver_probe_device+0x19/0xa0
__driver_attach+0xb6/0x180
? __pfx___driver_attach+0x10/0x10
bus_for_each_dev+0x77/0xd0
bus_add_driver+0x114/0x210
driver_register+0x5b/0x110
? __pfx_intel_lpss_pci_driver_init+0x10/0x10 [intel_lpss_pci]
do_one_initcall+0x57/0x2b0
? kmalloc_trace+0x21e/0x280
? do_init_module+0x1e/0x210
do_init_module+0x5f/0x210
load_module+0x1d37/0x1fc0
? init_module_from_file+0x86/0xd0
init_module_from_file+0x86/0xd0
idempotent_init_module+0x17c/0x230
__x64_sys_finit_module+0x56/0xb0
do_syscall_64+0x6e/0x140
entry_SYSCALL_64_after_hwframe+0x71/0x79
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.9): severity, escalated by confirmed exploitation. This CVE's 5.9 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.9 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 2026-10-25). 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