UBUNTU-CVE-2025-38097
In the Linux kernel, the following vulnerability has been resolved: espintcp: remove encap socket caching to avoid reference leak The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket.
02 / AFFECTED SOFTWARE
Affected packages
4 explicit affected versions
3 explicit affected versions
8 explicit affected versions
10 explicit affected versions
7 explicit affected versions
37 explicit affected versions
13 explicit affected versions
37 explicit affected versions
26 explicit affected versions
5 explicit affected versions
80 explicit affected versions
79 explicit affected versions
13 explicit affected versions
4 explicit affected versions
11 explicit affected versions
89 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
19 explicit affected versions
6 explicit affected versions
100 explicit affected versions
24 explicit affected versions
85 explicit affected versions
84 explicit affected versions
86 explicit affected versions
76 explicit affected versions
10 explicit affected versions
28 explicit affected versions
26 explicit affected versions
90 explicit affected versions
7 explicit affected versions
84 explicit affected versions
32 explicit affected versions
13 explicit affected versions
35 explicit affected versions
35 explicit affected versions
51 explicit affected versions
50 explicit affected versions
18 explicit affected versions
42 explicit affected versions
64 explicit affected versions
37 explicit affected versions
13 explicit affected versions
10 explicit affected versions
23 explicit affected versions
43 explicit affected versions
1 explicit affected versions
21 explicit affected versions
9 explicit affected versions
16 explicit affected versions
39 explicit affected versions
8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
5 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
45 explicit affected versions
7 explicit affected versions
9 explicit affected versions
12 explicit affected versions
12 explicit affected versions
32 explicit affected versions
7 explicit affected versions
23 explicit affected versions
25 explicit affected versions
10 explicit affected versions
68 explicit affected versions
10 explicit affected versions
13 explicit affected versions
31 explicit affected versions
2 explicit affected versions
10 explicit affected versions
5 explicit affected versions
26 explicit affected versions
3 explicit affected versions
13 explicit affected versions
37 explicit affected versions
29 explicit affected versions
13 explicit affected versions
6 explicit affected versions
96 explicit affected versions
32 explicit affected versions
32 explicit affected versions
92 explicit affected versions
55 explicit affected versions
33 explicit affected versions
77 explicit affected versions
23 explicit affected versions
60 explicit affected versions
10 explicit affected versions
11 explicit affected versions
10 explicit affected versions
11 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
69 explicit affected versions
93 explicit affected versions
10 explicit affected versions
26 explicit affected versions
31 explicit affected versions
1 explicit affected versions
38 explicit affected versions
5 explicit affected versions
13 explicit affected versions
37 explicit affected versions
51 explicit affected versions
16 explicit affected versions
91 explicit affected versions
41 explicit affected versions
3 explicit affected versions
7 explicit affected versions
2 explicit affected versions
18 explicit affected versions
33 explicit affected versions
12 explicit affected versions
71 explicit affected versions
80 explicit affected versions
27 explicit affected versions
66 explicit affected versions
34 explicit affected versions
8 explicit affected versions
55 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
3 explicit affected versions
3 explicit affected versions
39 explicit affected versions
44 explicit affected versions
16 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
42 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
11 explicit affected versions
30 explicit affected versions
13 explicit affected versions
92 explicit affected versions
8 explicit affected versions
7 explicit affected versions
81 explicit affected versions
1 explicit affected versions
1 explicit affected versions
1 explicit affected versions
91 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
36 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
10 explicit affected versions
30 explicit affected versions
80 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: espintcp: remove encap socket caching to avoid reference leak The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/028363685bd0b7a19b4a820f82dd905b1dc83999
- https://git.kernel.org/stable/c/028363685bd0b7a19b4a820f82dd905b1dc83999
- https://git.kernel.org/stable/c/74fd327767fb784c5875cf7c4ba1217f26020943
- https://git.kernel.org/stable/c/9cbca30102028f9ad3d2098f935c4368f581fd07
- https://git.kernel.org/stable/c/b58a295d10065960bcb9d60cb8ca6ead9837cd27
- https://git.kernel.org/stable/c/e4cde54b46a87231c77256a633be1bef62687d69
- https://ubuntu.com/security/CVE-2025-38097
- https://ubuntu.com/security/notices/USN-7769-1
- https://ubuntu.com/security/notices/USN-7769-2
- https://ubuntu.com/security/notices/USN-7769-3
- https://ubuntu.com/security/notices/USN-7770-1
- https://ubuntu.com/security/notices/USN-7771-1
- https://ubuntu.com/security/notices/USN-7789-1
- https://ubuntu.com/security/notices/USN-7789-2
- https://ubuntu.com/security/notices/USN-8028-1
- https://ubuntu.com/security/notices/USN-8028-2
- https://ubuntu.com/security/notices/USN-8028-3
- https://ubuntu.com/security/notices/USN-8028-4
- https://ubuntu.com/security/notices/USN-8028-5
- https://ubuntu.com/security/notices/USN-8028-6
- https://ubuntu.com/security/notices/USN-8028-7
- https://ubuntu.com/security/notices/USN-8028-8
- https://ubuntu.com/security/notices/USN-8031-1
- https://ubuntu.com/security/notices/USN-8031-2
- https://ubuntu.com/security/notices/USN-8031-3
- https://ubuntu.com/security/notices/USN-8052-1
- https://ubuntu.com/security/notices/USN-8052-2
- https://ubuntu.com/security/notices/USN-8074-1
- https://ubuntu.com/security/notices/USN-8074-2
- https://ubuntu.com/security/notices/USN-8126-1
- https://www.cve.org/CVERecord?id=CVE-2025-38097