CVE-2026-23064
Description
A NULL pointer dereference vulnerability was found in the Linux kernel's traffic control IFE (Inter-FE) action module. The tcf_ife_encode() function fails to verify that ife_encode() returns a valid pointer before use. When ife_encode() returns NULL, subsequent calls to ife_tlv_meta_encode() attempt to dereference the NULL pointer, triggering a kernel crash during packet processing.
Statement
This vulnerability was discovered by syzkaller and affects systems using the tc (traffic control) IFE action for inter-forwarding-element metadata encapsulation. Triggering this flaw requires the ability to configure traffic control rules, typically requiring root or CAP_NET_ADMIN privileges. The impact is denial of service through a kernel crash during packet transmission.
Mitigation
To mitigate this issue, prevent the act_ife module from being loaded if IFE traffic control actions are not required. See https://access.redhat.com/solutions/41278 for instructions on how to blacklist a kernel module.
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 | High | 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:H/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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