CVE-2026-97947

A flaw was found in the Linux kernel's x86 AMD node component, which may lead to a Denial of Service (DoS). If initialization of the AMD System Management Network (SMN) interface fails, exported read and write functions remain accessible without validating that internal device structures were allocated. A local attacker can exploit this flaw to trigger a NULL pointer dereference, resulting in a kernel crash.

A low impact NULL pointer dereference flaw was found in the Linux kernel's x86 AMD node (System Management Network, SMN) code. If initialization of the SMN interface fails during boot, for example when an exclusive PCI configuration region request fails, the internal 'amd_roots' root device array is never allocated, yet the exported amd_smn_read() and amd_smn_write() helper functions remain available to other kernel components. A local attacker who can trigger a kernel code path that performs an SMN access on such a system can cause a NULL pointer dereference in __amd_smn_rw(), resulting in a kernel crash and a local denial of service. Confidentiality and integrity are not affected. The vulnerable code is present in Red Hat Enterprise Linux 9 (9.8, 9.9, 9.10), Red Hat Enterprise Linux 10 (10.2, 10.3, 10.4), Red Hat In-Vehicle OS 2.0 and 2.1, and OpenShift Container Platform 4.22, 4.23, 5.0, and 5.1 (RHEL CoreOS 9) kernels. Red Hat Enterprise Linux 6, 7, and 8, RHEL 9.2, 9.4, 9.6, and 10.0, and earlier OpenShift Container Platform releases are not affected because the reworked x86/amd_node SMN code is not present in those kernels. The fix for the affected streams is deferred to a future update; the residual risk of this deferral is low because triggering the flaw requires both supported AMD hardware and an uncommon SMN initialization failure at boot, and the worst outcome is a local denial of service. Although the CVSS:3.1 base score is 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), Red Hat rates the impact of this flaw as Low because reliable exploitation depends on a prior, atypical initialization failure.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.