In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix locally exploitable BUG_ON in amdxdna_insert_pages()
In amdxdna_insert_pages(), vm_flags_mod() sets VM_MIXEDMAP and clears
VM_PFNMAP. If an unprivileged userspace process mmaps a non-imported GEM
object and then calls madvise(MADV_DONTNEED), the PTEs will be
successfully cleared because VM_MIXEDMAP allows this (unlike VM_PFNMAP).
When userspace subsequently accesses the memory, drm_gem_shmem_fault()
handles the page fault and attempts to map the backing shmem page via
vmf_insert_pfn() which calls vmf_insert_pfn_prot(). Because the backing
shmem page is normal system memory (pfn_valid(pfn) is true) and the VMA
now has VM_MIXEDMAP set, won't this predictably trigger the explicit
assertion BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn))
Fix by removing the vm_flags_mod() call and replacing the vm_insert_pages()
pre-population with the handle_mm_fault() loop that was already used for
the import (dma-buf) path.
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 2026-10-24). 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