In the Linux kernel, the following vulnerability has been resolved:
cxl/region: Fill first free targets[] slot during auto-discovery
Any invalid endpoint decoder pointer in the target array of an active
region is not allowed by cxl driver. This means cxl driver always
assumes the first p->nr_targets entries of the target array in an
auto-assembly region are valid. However, there are scenarios that could
leave NULL endpoint decoder pointer holes in the target array.
- When cxl_cancel_auto_attach() removes an endpoint decoder from a
target array, the target slot is set to NULL. If the removed endpoint
decoder is not the last element in the target array, the target array
will contain a NULL hole.
- When a auto-assembly region removes an assigned endpoint decoder, if
the removed endpoint decoder is not the last element in the target
array, always remains a NULL hole in the target array.
When a NULL pointer hole exists in a region's target array, it
introduces two potential problems:
- Access an endpoint decoder via a NULL pointer. it always trigger
calltrace like that.
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN PTI
RIP: 0010:cxl_calc_interleave_pos+0x26/0x810 [cxl_core]
Call Trace:
cxl_region_attach+0xc50/0x2140 [cxl_core]
cxl_add_to_region+0x321/0x2330 [cxl_core]
discover_region+0x92/0x150 [cxl_port]
device_for_each_child+0xf3/0x170
cxl_port_probe+0x150/0x200 [cxl_port]
cxl_bus_probe+0x4f/0xa0 [cxl_core]
really_probe+0x1c8/0x960
__driver_probe_device+0x323/0x450
driver_probe_device+0x45/0x120
__device_attach_driver+0x15d/0x280
bus_for_each_drv+0x10f/0x190
- Not having enough valid endpoint decoders attached to an
auto-assembly region. if an auto-assembly region is created with lock
flag or assigned endpoint decoder with lock flag, which means
assigned endpoint decoder will not be reset during detaching, they
could re-attach to the auto-assembly region again. But cxl region
driver relies on p->nr_targets to verify whether the required number
of endpoint decoders has been attached, and NULL endpoint decoder
pointers are still counted in that case.
To fix above issues, adjust cxl_region_attach_auto() logic to find the
first free target slot for endpoint decoder attachment, this ensures
NULL holes in the target array are filled, rather than adding new
endpoint decoders at the tail of the target array.
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 2026-10-17). 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