CVE-2024-53176
Description
A flaw was found in the Linux kernel's SMB/CIFS client. A race condition can occur during unmount operations when closing cached directories while concurrent background directory cleanup or server reconnection tasks are underway. This timing error prevents cached directory entries from being released properly, triggering a kernel crash. An authorized local user can trigger this issue during share unmount operations, resulting in a Denial of Service (DoS).
Mitigation
Prevent loading of the `cifs` kernel module if SMB/CIFS network file systems are not required.
1. Blacklist the kernel module by creating a configuration file:
# echo "install cifs /bin/true" > /etc/modprobe.d/disable-cifs.conf
2. If the module is currently loaded and no SMB shares are mounted, unload it:
# rmmod cifs
Caveats: Disabling this module prevents the system from mounting or accessing CIFS/SMB network shares.
Warning: If CIFS shares are currently mounted or the module is actively in use, a system reboot is required for this change to take full 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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 4.7 | 9.8 |
| Attack Vector | Local | Local | Network |
| Attack Complexity | Low | High | Low |
| Privileges Required | Low | Low | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | High |
| Integrity Impact | None | None | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity
Technical Impact: Read Application Data; Modify Application Data; Read Files or Directories; Modify Files or Directories
An attacker could gain access to or modify sensitive data or system resources. This could allow access to protected files or directories including configuration files and files containing sensitive information.
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