CVE-2026-97947

/// Technical description

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

x86/amd_node: Fix potential NULL pointer dereference

amd_smn_read/write() are exported functions around __amd_smn_rw(), so

they are always available even if amd_smn_init() fails. In that case,

'amd_roots' is NULL and __amd_smn_rw() will access uninitialized memory.

Then, commit:

83518453074d ("x86/amd_node: Add SMN offsets to exclusive region access")

added the 'smn_exclusive' flag, which indicated the calls to

pci_request_config_region_exclusive() succeeded, to prevent

concurrent userspace access.

Commit:

0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")

re-ordered initialization so pci_request_config_region_exclusive() is

called earlier and a failure exits amd_smn_init() before allocating

'amd_roots'. The setting of 'smn_exclusive' moved to the end of

amd_smn_init(), after 'amd_roots' is allocated. It became redundant

and can be removed.

Replace 'smn_exclusive' with directly checking 'amd_roots'

/// 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