CVE-2023-53568
Description
A resource leak was found in the Linux kernel's s390 cryptographic device driver in the device creation path. When the dev_set_name function fails during creation of a zcrypt device node, the zcdn_create function returns an error without freeing the newly allocated device structure and associated resources. This creates a permanent memory leak, leading to resource exhaustion and denial of service.
Statement
The z/Architecture cryptographic device interface allows creation of additional device nodes for accessing crypto hardware. The zcdn_create function allocates a device structure and attempts to assign it a name using dev_set_name. If this naming operation fails—perhaps due to name collisions, memory allocation failures, or invalid characters—the function immediately returns an error code. At this point, the device structure has been allocated but never registered with the device core, so there's no automatic cleanup mechanism in place. The allocated memory, along with any other resources acquired during partial initialization, becomes orphaned. While dev_set_name failures are presumably rare in practice, any failure creates a leak that persists until system reboot. This is specific to s390 architecture systems with cryptographic hardware.
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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