CVE-2026-80651
Description
A flaw was found in the Linux kernel's crypto: ccp/sev-dev-tsm module. The dsm_create() function fails to properly validate the pdev->bus pointer, leading to a null pointer dereference. A local attacker could exploit this vulnerability to trigger a kernel crash, resulting in a Denial of Service (DoS).
Statement
A flaw of moderate severity was found in the Linux kernel's crypto: ccp/sev-dev-tsm module (drivers/crypto/ccp/sev-dev-tsm.c). The dsm_create() function conditionally handles a NULL pdev->bus pointer when computing the PCI segment ID, but the following statements dereference pdev->bus unconditionally through pcie_find_root_port() and pci_dev_id(). A local attacker able to reach the SEV TIO setup path with a PCI device whose pdev->bus is NULL could trigger this null pointer dereference, causing a kernel crash and resulting in a denial of service. The Red Hat CVSS v3.1 severity is moderate, with a score of 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). The affected SEV TSM code was introduced in the upstream Linux kernel in version 6.19 and is not present in any shipped Red Hat Enterprise Linux or Red Hat In-Vehicle OS kernel. All Red Hat kernel and kernel-rt offerings have therefore been assessed as not affected, because the vulnerable code is not present in the shipped kernels.
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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