CVE-2026-74721

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

accel/amxdna: Fix page-insertion errors in amdxdna_insert_pages()

Two error paths in amdxdna_insert_pages() called vma->vm_ops->close(vma)

before returning an error code to the caller. This is incorrect:

amdxdna_gem_obj_mmap() registers an HMM interval notifier before calling

amdxdna_insert_pages(), and on a hard error it jumps to hmm_unreg to undo

that registration. Calling vm_ops->close() manually — which drops the

shmem pages_pin_count and the GEM object reference that backs the VMA —

before the mmap syscall has even returned causes those resources to be

released while the VMA is still alive. The kernel VMA teardown will call

vm_ops->close() a second time when the process later unmaps the range,

producing a reference count underflow.

Replace both hard-error returns with a deferred-fault approach that keeps

the VMA alive and retries page insertion through the HMM range-fault path.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References