In the Linux kernel, the following vulnerability has been resolved: net/l2tp: fix warning in l2tp_exit_net found by syzbot In l2tp's net exit handler, we check that an IDR is empty before destroying it: WARN_ON_ONCE(!idr_is_empty(&pn->l2tp_tunnel_idr)); idr_destroy(&pn->l2tp_tunnel_idr); By forcing memory allocation failures in idr_alloc_32, syzbot is able to provoke a condition where idr_is_empty returns false despite there being no items in the IDR. This turns out to be because the radix tree of the IDR contains only internal radix-tree nodes and it is this that causes idr_is_empty to return false. The internal nodes are cleaned by idr_destroy. Use idr_for_each to check that the IDR is empty instead of idr_is_empty to avoid the problem.
History

Mon, 30 Dec 2024 01:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Fri, 27 Dec 2024 14:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net/l2tp: fix warning in l2tp_exit_net found by syzbot In l2tp's net exit handler, we check that an IDR is empty before destroying it: WARN_ON_ONCE(!idr_is_empty(&pn->l2tp_tunnel_idr)); idr_destroy(&pn->l2tp_tunnel_idr); By forcing memory allocation failures in idr_alloc_32, syzbot is able to provoke a condition where idr_is_empty returns false despite there being no items in the IDR. This turns out to be because the radix tree of the IDR contains only internal radix-tree nodes and it is this that causes idr_is_empty to return false. The internal nodes are cleaned by idr_destroy. Use idr_for_each to check that the IDR is empty instead of idr_is_empty to avoid the problem.
Title net/l2tp: fix warning in l2tp_exit_net found by syzbot
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-12-27T13:49:57.169Z

Updated: 2025-05-04T09:56:00.933Z

Reserved: 2024-11-19T17:17:25.020Z

Link: CVE-2024-53211

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2024-12-27T14:15:29.017

Modified: 2024-12-27T14:15:29.017

Link: CVE-2024-53211

cve-icon Redhat

Severity : Low

Publid Date: 2024-12-27T00:00:00Z

Links: CVE-2024-53211 - Bugzilla