In the Linux kernel, the following vulnerability has been resolved:
l2tp: prevent possible tunnel refcount underflow
When a session is created, it sets a backpointer to its tunnel. When
the session refcount drops to 0, l2tp_session_free drops the tunnel
refcount if session->tunnel is non-NULL. However, session->tunnel is
set in l2tp_session_create, before the tunnel refcount is incremented
by l2tp_session_register, which leaves a small window where
session->tunnel is non-NULL when the tunnel refcount hasn't been
bumped.
Moving the assignment to l2tp_session_register is trivial but
l2tp_session_create calls l2tp_session_set_header_len which uses
session->tunnel to get the tunnel's encap. Add an encap arg to
l2tp_session_set_header_len to avoid using session->tunnel.
If l2tpv3 sessions have colliding IDs, it is possible for
l2tp_v3_session_get to race with l2tp_session_register and fetch a
session which doesn't yet have session->tunnel set. Add a check for
this case.
References
Configurations
History
13 Nov 2024, 13:26
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/24256415d18695b46da06c93135f5b51c548b950 - Patch | |
| References | () https://git.kernel.org/stable/c/f7415e60c25a6108cd7955a20b2e66b6251ffe02 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| First Time |
Linux
Linux linux Kernel |
|
| CWE | NVD-CWE-noinfo | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
21 Oct 2024, 18:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2024-10-21 18:15
Updated : 2024-11-13 13:26
NVD link : CVE-2024-49940
Mitre link : CVE-2024-49940
JSON object : View
Products Affected
linux
- linux_kernel
CWE