Bug 2373564 (CVE-2022-50071)

Summary: CVE-2022-50071 kernel: mptcp: move subflow cleanup in mptcp_destroy_common()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: low    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-06-18 12:08:32 UTC 
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.
Comment 1 Avinash Hanwate 2025-06-19 11:36:29 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025061853-CVE-2022-50071-874c@gregkh/T