Kernel crash via negative send length return
Published Sep 18, 2024 · Updated May 12, 2026
Improper value handling in the Linux kernel allows local users to crash the system through a corked TCP BPF socket message. During a drop verdict, tcp_bpf_send_verdict subtracts the flushed message length and delta from copied, allowing tcp_bpf_sendmsg to return a negative byte count that violates the socket send contract and reaches a kernel BUG. Exploitation requires local low-privilege access and the TCP BPF verdict path; the demonstrated consequence is a system crash, not data access or modification.
Summary
What happened
Improper value handling in the Linux kernel allows local users to crash the system through a corked TCP BPF socket message. During a drop verdict, tcp_bpf_send_verdict subtracts the flushed message length and delta from copied, allowing tcp_bpf_sendmsg to return a negative byte count that violates the socket send contract and reaches a kernel BUG. Exploitation requires local low-privilege access and the TCP BPF verdict path; the demonstrated consequence is a system crash, not data access or modification.
The record
- CVE
- CVE-2024-46783
- Published
- Sep 18, 2024
- Updated
- May 12, 2026
- Vendor
- Siemens
- Product
- SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family
- Classifications
- CWE-229, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 18, 2024CVE publishedPublication date reported by the CVE source.
- May 12, 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=0 <V3.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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