Task hang via duplicate action index loop
Published Jul 12, 2024 · Updated May 12, 2026
Infinite loop in Linux allows local users with network-admin privileges to hang tasks through duplicate traffic-control action indexes. tcf_idr_check_alloc() retries allocation indefinitely when a second action in one request reuses an index reserved by the first. Creating traffic-control actions requires network-administration privilege, and the loop holds rtnl_lock, blocking unrelated networking work.
Summary
What happened
Infinite loop in Linux allows local users with network-admin privileges to hang tasks through duplicate traffic-control action indexes. tcf_idr_check_alloc() retries allocation indefinitely when a second action in one request reuses an index reserved by the first. Creating traffic-control actions requires network-administration privilege, and the loop holds rtnl_lock, blocking unrelated networking work.
The record
- CVE
- CVE-2024-40995
- Published
- Jul 12, 2024
- Updated
- May 12, 2026
- Vendor
- Siemens
- Product
- SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
- Classifications
- CWE-835, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 12, 2024CVE publishedPublication date reported by the CVE source.
- May 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=0 <*
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Published CVSS scores
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Attacks
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Technologies
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