Local denial of service via MPTCP timer self-deadlock
Published May 28, 2026 · Updated May 28, 2026
Denial of service in affected Linux Kernel releases starting at 5.10 allows local users to hang systems via MPTCP ADD_ADDR retransmission. In net/mptcp/pm.c, the retransmission timer releases its held socket with __sock_put(); using sock_put() on the final reference instead invokes sk_free(), whose sk_stop_timer_sync() waits on the currently executing timer. Reachability requires low-privileged local access, MPTCP socket creation, and an ADD_ADDR retransmission that drops the socket's final reference; the self-wait then hangs the affected kernel path.
Summary
What happened
Denial of service in affected Linux Kernel releases starting at 5.10 allows local users to hang systems via MPTCP ADD_ADDR retransmission. In net/mptcp/pm.c, the retransmission timer releases its held socket with __sock_put(); using sock_put() on the final reference instead invokes sk_free(), whose sk_stop_timer_sync() waits on the currently executing timer. Reachability requires low-privileged local access, MPTCP socket creation, and an ADD_ADDR retransmission that drops the socket's final reference; the self-wait then hangs the affected kernel path.
The record
- CVE
- CVE-2026-46170
- Published
- May 28, 2026
- Updated
- May 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 28, 2026CVE publishedPublication date reported by the CVE source.
- May 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=00cfd77b9063dcdf3628a7087faba60de85a9cc8 <8143a224785ceaf2b0856e08d4498916f38228fb
- Affected versionversion=00cfd77b9063dcdf3628a7087faba60de85a9cc8 <b74ad20198652b6b39a761c277ba65ae82b1e107
- Affected versionversion=00cfd77b9063dcdf3628a7087faba60de85a9cc8 <b7b9a461569734d33d3259d58d2507adfac107ed
- Affected versionversion=5.10
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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