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.
Metrics
Affected Vendors & Products
References
History
Mon, 30 Dec 2024 01:30:00 +0000
Type | Values Removed | Values Added |
---|---|---|
References |
| |
Metrics |
threat_severity
|
cvssV3_1
|
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 |
|

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

No data.

Status : Received
Published: 2024-12-27T14:15:29.017
Modified: 2024-12-27T14:15:29.017
Link: CVE-2024-53211
