Kernel service interruption via MPTCP signedness error
Published May 21, 2024 · Updated May 11, 2026
Incorrect comparison in Linux kernel MPTCP 5.14.7 through 5.14.8 allows local users to trigger a kernel warning and service interrupt. In mptcp_sendmsg_frag, subtracting unsigned skb length from signed size_goal makes an oversized buffer appear below the goal, skips transmit-cache refill, and leaves a core TCP buffer without the required MPTCP extension. Low-privileged local access and an MPTCP send path are required; the documented consequence is availability loss, with no confidentiality or integrity impact.
Summary
What happened
Incorrect comparison in Linux kernel MPTCP 5.14.7 through 5.14.8 allows local users to trigger a kernel warning and service interrupt. In mptcp_sendmsg_frag, subtracting unsigned skb length from signed size_goal makes an oversized buffer appear below the goal, skips transmit-cache refill, and leaves a core TCP buffer without the required MPTCP extension. Low-privileged local access and an MPTCP send path are required; the documented consequence is availability loss, with no confidentiality or integrity impact.
The record
- CVE
- CVE-2021-47370
- Published
- May 21, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-697, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 21, 2024CVE publishedPublication date reported by the CVE source.
- May 11, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1094c6fe7280e17e0e87934add5ad2585e990def <977d293e23b48a1129830d7968605f61c4af71a0
- Affected versionversion=5.14.7 <5.14.9
- Affected versionversion=e35820fb56415be6924bf552ec223ed5f347b4be <f8ff625a8082db8c2b58dcb5229b27928943b94b
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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