CVE-2026-97947
Description
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.
Statement
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.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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