CVE-2026-23123
Description
A flaw was found in the Linux kernel's interconnect debugfs test client. This vulnerability arises from the use of uninitialized pointers when handling debugfs entries. A local user with sufficient privileges could exploit this by accessing these debugfs entries. Successful exploitation could lead to a kernel crash, causing a local denial of service (DoS). There is also a theoretical risk of memory corruption.
Statement
The issue is in the interconnect debugfs test client. The debugfs_create_str API assumes that the backing pointer is either NULL or points to valid dynamically allocated memory. Before this change src_node and dst_node could be left uninitialized, meaning they might contain arbitrary stack or global garbage values. When the debugfs files are accessed, the debugfs str ing helpers may dereference the pointer to print the string, or may attempt to update it on write. With an uninitialized pointer this can lead to a kernel crash due to an invalid dereference, producing a local denial of service. Depending on the exact debugfs string implementation and write path behavior, there is also a more theoretical risk of memory corruption if the subsystem attempts to treat the garbage pointer as a valid allocation. Access requires local privileges sufficient to read or write the debugfs entries. In many deployments debugfs is restricted to root and may not be mounted.
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 | 4.4 | 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 | Low | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L
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,Integrity,Other
Technical Impact: Other
Initial variables usually contain junk, which can not be trusted for consistency. This can lead to denial of service conditions, or modify control flow in unexpected ways. In some cases, an attacker can "pre-initialize" the variable using previous actions, which might enable code execution. This can cause a race condition if a lock variable check passes when it should not.
Authorization,Other
Technical Impact: Other
Strings that are not initialized are especially dangerous, since many functions expect a null at the end -- and only at the end -- of a string.
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