CVE-2022-50858

Description

A flaw was found in the Linux kernel's Alcor Micro MMC card reader driver. When mmc_add_host() fails, its return value is not checked, causing memory allocated by mmc_alloc_host() to leak. Additionally, the remove path may attempt to delete a device that was never added, leading to a kernel crash.

Statement

This bug manifests only when mmc_add_host() fails during driver initialization, which is an uncommon error condition. The memory leak and potential crash affect systems with Alcor Micro card readers encountering initialization failures, representing a limited attack surface that requires specific hardware.

Mitigation

To mitigate this issue, prevent the alcor module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.

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 HatNVDcve.org
Base Score3.3N/AN/A
Attack VectorLocalN/AN/A
Attack ComplexityLowN/AN/A
Privileges RequiredLowN/AN/A
User InteractionNoneN/AN/A
ScopeUnchangedN/AN/A
ConfidentialityNoneN/AN/A
Integrity ImpactNoneN/AN/A
Availability ImpactLowN/AN/A

Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Understanding the Weakness (CWE)

CWE-252

Availability,Integrity

Technical Impact: Unexpected State; DoS: Crash, Exit, or Restart

An unexpected return value could place the system in a state that could lead to a crash or other unintended behaviors.

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