CVE-2023-53629
Description
A flaw was found in the Linux kernel, specifically within the Distributed Lock Manager (DLM) midcomms component. A timing issue, known as a race condition, can occur during message processing. This can lead to a 'use-after-free' vulnerability, where the system attempts to use memory that has already been released. Exploitation of this flaw can cause the kernel to crash, resulting in a Denial of Service (DoS) for the affected system.
Statement
A race in DLM midcomms (dlm_midcomms_commit_mhandle() for v3.2) could free a message handle upon an early ACK while it’s still being used, leading to a kernel UAF and crash. The fix surrounds the commit path with RCU read locking to prevent premature reclamation.
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 | 6.7 | 7.8 | 9.8 |
| Attack Vector | Adjacent Network | Local | Network |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | Low | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | Low | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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