UBUNTU-CVE-2024-26826
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix data re-injection from stale subflow When the MPTCP PM detects that a subflow is stale, all the packet scheduler must re-inject all the mptcp-level unacked data. To avoid acquiring unneeded locks, it first try to check if any unacked data is present at all in the RTX queue, but such check is currently broken, as it uses TCP-specific helper on an MPTCP socket. Funnily enough fuzzers and static checkers are happy, as the accessed memory still belongs to the mptcp_sock struct, and even from a functional perspective the recovery completed successfully, as the short-cut test always failed. A recent unrelated TCP change - commit d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") - exposed the issue, as the tcp field reorganization makes the mptcp code always skip the re-inection. Fix the issue dropping the bogus call: we are on a slow path, the early optimization proved once again to be evil.
02 / AFFECTED SOFTWARE
Affected packages
9 explicit affected versions
29 explicit affected versions
41 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
18 explicit affected versions
6 explicit affected versions
50 explicit affected versions
36 explicit affected versions
47 explicit affected versions
36 explicit affected versions
10 explicit affected versions
43 explicit affected versions
7 explicit affected versions
44 explicit affected versions
11 explicit affected versions
35 explicit affected versions
3 explicit affected versions
14 explicit affected versions
18 explicit affected versions
5 explicit affected versions
30 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
21 explicit affected versions
9 explicit affected versions
16 explicit affected versions
10 explicit affected versions
7 explicit affected versions
12 explicit affected versions
34 explicit affected versions
12 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
12 explicit affected versions
10 explicit affected versions
37 explicit affected versions
11 explicit affected versions
10 explicit affected versions
23 explicit affected versions
26 explicit affected versions
13 explicit affected versions
4 explicit affected versions
29 explicit affected versions
13 explicit affected versions
47 explicit affected versions
45 explicit affected versions
7 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
11 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
36 explicit affected versions
28 explicit affected versions
44 explicit affected versions
10 explicit affected versions
26 explicit affected versions
1 explicit affected versions
13 explicit affected versions
16 explicit affected versions
47 explicit affected versions
37 explicit affected versions
3 explicit affected versions
2 explicit affected versions
51 explicit affected versions
1 explicit affected versions
12 explicit affected versions
34 explicit affected versions
27 explicit affected versions
20 explicit affected versions
8 explicit affected versions
8 explicit affected versions
5 explicit affected versions
8 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
7 explicit affected versions
39 explicit affected versions
10 explicit affected versions
12 explicit affected versions
12 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
33 explicit affected versions
37 explicit affected versions
12 explicit affected versions
38 explicit affected versions
37 explicit affected versions
9 explicit affected versions
36 explicit affected versions
11 explicit affected versions
44 explicit affected versions
8 explicit affected versions
7 explicit affected versions
18 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
42 explicit affected versions
11 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
9 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix data re-injection from stale subflow When the MPTCP PM detects that a subflow is stale, all the packet scheduler must re-inject all the mptcp-level unacked data. To avoid acquiring unneeded locks, it first try to check if any unacked data is present at all in the RTX queue, but such check is currently broken, as it uses TCP-specific helper on an MPTCP socket. Funnily enough fuzzers and static checkers are happy, as the accessed memory still belongs to the mptcp_sock struct, and even from a functional perspective the recovery completed successfully, as the short-cut test always failed. A recent unrelated TCP change - commit d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") - exposed the issue, as the tcp field reorganization makes the mptcp code always skip the re-inection. Fix the issue dropping the bogus call: we are on a slow path, the early optimization proved once again to be evil.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/b6c620dc43ccb4e802894e54b651cf81495e9598
- https://git.kernel.org/stable/c/624902eab7abcb8731b333ec73f206d38d839cd8
- https://git.kernel.org/stable/c/6673d9f1c2cd984390550dbdf7d5ae07b20abbf8
- https://git.kernel.org/stable/c/6f95120f898b40d13fd441225ef511307853c9c2
- https://git.kernel.org/stable/c/b609c783c535493aa3fca22c7e40a120370b1ca5
- https://git.kernel.org/stable/c/b6c620dc43ccb4e802894e54b651cf81495e9598
- https://ubuntu.com/security/CVE-2024-26826
- https://ubuntu.com/security/notices/USN-6766-1
- https://ubuntu.com/security/notices/USN-6766-2
- https://ubuntu.com/security/notices/USN-6766-3
- https://ubuntu.com/security/notices/USN-6795-1
- https://ubuntu.com/security/notices/USN-6828-1
- https://ubuntu.com/security/notices/USN-6895-1
- https://ubuntu.com/security/notices/USN-6895-2
- https://ubuntu.com/security/notices/USN-6895-3
- https://ubuntu.com/security/notices/USN-6895-4
- https://ubuntu.com/security/notices/USN-6900-1
- https://www.cve.org/CVERecord?id=CVE-2024-26826