CVE-2022-50479
Description
A memory leak was found in the Linux kernel's AMD display driver in the clock source initialization logic. When the initialization function encounters an error in its final return path, allocated memory for the clk_src structure is not freed before returning NULL. This results in leaked memory that accumulates with repeated initialization attempts, leading to resource exhaustion and denial of service.
Statement
The AMD display driver allocates memory for clock source structures during hardware initialization. In one particular error path—specifically, when the function reaches its last return NULL statement—the code fails to free the previously allocated clk_src memory. While this appears to be a straightforward oversight, it can become significant during scenarios where initialization repeatedly fails, such as during hardware probing, driver reload cycles, or error recovery attempts. Each failed initialization leaves behind orphaned memory that cannot be reclaimed. The leak is specific to AMD display hardware and manifests during driver initialization rather than during normal runtime operation.
Mitigation
To mitigate this issue, prevent the amdgpu module from being loaded. See https://access.redhat.com/solutions/41278 for instructions on blacklisting kernel modules.
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 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
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:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Frequently Asked Questions
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