In the Linux kernel, the following vulnerability has been resolved: sch_htb: fix refcount leak in htb_parent_to_leaf_offload The commit ae81feb7338c ("sch_htb: fix null pointer dereference on a null new_q") fixes a NULL pointer dereference bug, but it is not correct. Because htb_graft_helper properly handles the case when new_q is NULL, and after the previous patch by skipping this call which creates an inconsistency : dev_queue->qdisc will still point to the old qdisc, but cl->parent->leaf.q will point to the new one (which will be noop_qdisc, because new_q was NULL). The code is based on an assumption that these two pointers are the same, so it can lead to refcount leaks. The correct fix is to add a NULL pointer check to protect qdisc_refcount_inc inside htb_parent_to_leaf_offload.
History

Tue, 05 Nov 2024 08:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-03-15T20:14:30.285Z

Updated: 2024-11-04T11:59:54.271Z

Reserved: 2024-03-04T18:12:48.839Z

Link: CVE-2021-47125

cve-icon Vulnrichment

Updated: 2024-08-04T05:24:39.885Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-03-15T21:15:07.307

Modified: 2024-03-17T22:38:29.433

Link: CVE-2021-47125

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-03-15T00:00:00Z

Links: CVE-2021-47125 - Bugzilla