Kernel crash or memory corruption via QFQ race
Published Jul 28, 2025 · Updated Aug 5, 2026
Race condition in Linux QFQ scheduling allows local users to crash the kernel or corrupt memory through concurrent class operations. The qfq_change_agg path modifies a qfq_aggregate during enqueue while qfq_dump_class and qfq_delete_class read or free it without the scheduler tree lock. Exploitation requires local low-privileged access and concurrent QFQ class operations; the observed outcomes are a kernel crash or use-after-free memory corruption.
Summary
What happened
Race condition in Linux QFQ scheduling allows local users to crash the kernel or corrupt memory through concurrent class operations. The qfq_change_agg path modifies a qfq_aggregate during enqueue while qfq_dump_class and qfq_delete_class read or free it without the scheduler tree lock. Exploitation requires local low-privileged access and concurrent QFQ class operations; the observed outcomes are a kernel crash or use-after-free memory corruption.
The record
- CVE
- CVE-2025-38477
- Published
- Jul 28, 2025
- Updated
- Aug 5, 2026
- Vendor
- Siemens
- Product
- SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
- Classifications
- CWE-362
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 28, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=V3.1.5 <*
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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