CVE-2023-54258
Description
A flaw was found in the Linux kernel's Common Internet File System (CIFS) client. A race condition can occur when the system handles file closes and network lease breaks simultaneously with an unmount operation. This timing issue can lead to a kernel crash, resulting in a Denial of Service (DoS) for the affected system. While a remote server can influence this, local system conditions are also required to trigger the vulnerability.
Statement
A race in the CIFS client oplock break worker can lead to a kernel oops when deferred close and lease break handling overlap with an unmount that tears down the session and server pointers. This happens because cifs_oplock_break may attempt to issue an oplock_response while the tree disconnect path is concurrently invalidating tcon ses and server state. The issue can be influenced by a remote SMB server that sends lease break events but it is not a pure network only attack because the race requires local teardown timing. Impact is denial of service via kernel crash.
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 | 5.8 | N/A | 9.8 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/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)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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