CVE-2022-50071
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: mptcp: move subflow cleanup in mptcp_destroy_common() If the mptcp socket creation fails due to a CGROUP_INET_SOCK_CREATE eBPF program, the MPTCP protocol ends-up leaking all the subflows: the related cleanup happens in __mptcp_destroy_sock() that is not invoked in such code path. Address the issue moving the subflow sockets cleanup in the mptcp_destroy_common() helper, which is invoked in every msk cleanup path. Additionally get rid of the intermediate list_splice_init step, which is an unneeded relic from the past. The issue is present since before the reported root cause commit, but any attempt to backport the fix before that hash will require a complete rewrite.
Statement
The issue leads to a memory/socket leak when an MPTCP socket fails to initialize due to a CGROUP_INET_SOCK_CREATE eBPF hook. Subflows are not cleaned up in this failure path, resulting in leaked resources. The bug is not directly exploitable and causes minor local denial of service in rare configurations.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 2.3 | 7.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | High | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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