CVE-2023-52811
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: scsi: ibmvfc: Remove BUG_ON in the case of an empty event pool In practice the driver should never send more commands than are allocated to a queue's event pool. In the unlikely event that this happens, the code asserts a BUG_ON, and in the case that the kernel is not configured to crash on panic returns a junk event pointer from the empty event list causing things to spiral from there. This BUG_ON is a historical artifact of the ibmvfc driver first being upstreamed, and it is well known now that the use of BUG_ON is bad practice except in the most unrecoverable scenario. There is nothing about this scenario that prevents the driver from recovering and carrying on. Remove the BUG_ON in question from ibmvfc_get_event() and return a NULL pointer in the case of an empty event pool. Update all call sites to ibmvfc_get_event() to check for a NULL pointer and perfrom the appropriate failure or recovery action.
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 | N/A | 5.5 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: 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: 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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