CVE-2024-42300

Description

A flaw was found in the Linux kernel's erofs filesystem. A race condition in the z_erofs_get_gbuf() function could allow a local attacker to trigger a kernel bug, leading to a system crash and a Denial of Service (DoS).

Mitigation

To mitigate this issue, prevent the 'erofs' kernel module from loading. This can be achieved by blacklisting the module. Note that this will prevent the system from mounting EROFS filesystems.

Create a file named `/etc/modprobe.d/blacklist-erofs.conf` with the following content:

blacklist erofs

After creating the file, regenerate the initramfs to ensure the blacklist is applied on boot. The exact command varies by distribution, but common examples include:

For systems using Dracut:
`sudo dracut -f -v`

For systems using mkinitcpio:
`sudo mkinitcpio -P`

A system reboot is required for the changes to take effect.

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 HatNVDcve.org
Base Score4.74.77.8
Attack VectorLocalLocalLocal
Attack ComplexityHighHighLow
Privileges RequiredLowLowLow
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityNoneNoneHigh
Integrity ImpactNoneNoneHigh
Availability ImpactHighHighHigh

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:H/PR:L/UI:N/S:U/C:N/I:N/A:H

cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)

When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion.

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability

When a race condition allows multiple control flows to access a resource simultaneously, it might lead the product(s) into unexpected states, possibly resulting in a crash.

Confidentiality,Integrity

Technical Impact: Read Files or Directories; Read Application Data

When a race condition is combined with predictable resource names and loose permissions, it may be possible for an attacker to overwrite or access confidential data (CWE-59).

Access Control

Technical Impact: Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Bypass Protection Mechanism

This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.

Frequently Asked Questions

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