CVE-2022-48811
Description
A vulnerability was found in the Linux kernel's ibmvnic driver, where the __ibmvnic_open() function improperly releases NAPI structures on error. This occurs when the function encounters an issue while setting the link state, leading to a NULL pointer dereference. The impact of this vulnerability could result in system crashes, disrupting network operations.
Statement
A denial of service vulnerability was found in the Linux kernel's ibmvnic driver in Red Hat Enterprise Linux 8 and 9 (kernel and kernel-rt) and in Red Hat's Hosted OpenShift offerings (ARO and OSD). When __ibmvnic_open() encounters an error such as a failure while setting the link state, it calls release_resources(), which frees NAPI structures that are still referenced on later open attempts. On IBM Power systems using an ibmvnic interface, repeatedly adding or removing a vNIC (for example via the drmgr command) can drive a reset path that dereferences the released structures, causing a kernel NULL pointer dereference and a system crash that disrupts network operations. Red Hat rates this flaw Moderate severity (CVSS 3.1: 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H); only availability is affected, and triggering the crash requires local privileged access to an affected system. This matches the NIST CVSS assessment. The affected Red Hat Enterprise Linux maintenance update streams have been marked as won't fix for this issue, so the residual risk of a local denial of service remains on those streams. Red Hat Enterprise Linux 7 Extended Lifecycle Support is out of support scope, and Red Hat Enterprise Linux 6 Extended Lifecycle Support and Fedora are marked not affected by this flaw.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 5.5 | 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: 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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