CVE-2021-33630
kernel: net/sched: cbs NULL pointer dereference when offloading is enabled
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · January 18, 2024
Updated · August 7, 2026
Description
A NULL pointer dereference flaw was found in the Linux kernel's network scheduler. This issue occurs when offloading is enabled, the cbs instance is not added to the list. The code also incorrectly handles the case when offload is disabled without removing the qdisc. This could allow a local user to cause a denial of service condition.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
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.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-476 · NULL Pointer Dereference