CVE-2022-50470
Description
A null pointer/list corruption flaw was found in the Linux kernel USB xHCI host controller code. When the xHCI host is dying or being removed, some device endpoints may remain on the software bandwidth list. Later cleanup deletes entries that were already freed, corrupting the list and crashing the kernel. A local user could use this flaw to crash system, causing denial of service.
Statement
This vulnerability is limited to systems using software bandwidth checking, noted as affecting Intel Panther Point PCH (Ivy Bridge) xHC; other hosts perform bandwidth checks in hardware. The crash occurs when endpoints aren’t dropped cleanly as the controller is removed/dies, leaving them on the bandwidth list; subsequent free-path cleanup (xhci_mem_cleanup) attempts to delete already-freed endpoints, corrupting the list and triggering a kernel crash.
Mitigation
To mitigate this issue, prevent module xhci_pci from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | 7.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
