Syscall arguments can be misleading because the value captured in user space is not always the value the kernel uses. Relative paths can resolve differently, symbolic links can point somewhere else, and TOCTOU races can change input between check and use. Monitoring that depends only on syscall arguments can miss the true execution path and weaken detection quality.
Why syscall arguments alone do not tell the full truth
Syscall arguments are only the user space view of an operation. By the time the kernel resolves a path, applies mount rules, follows or rejects symlinks, or checks permissions, the effective target can differ from what was originally passed in. That gap matters because monitoring built on raw arguments can misrepresent what actually happened.
The main issue is that a syscall argument often names intent, not outcome. A path string may point to one object at capture time and another at execution time, and a race can change the object between inspection and use. For detection, the kernel-resolved result is usually more important than the text that arrived from the process.
How path resolution and timing gaps create blind spots
Relative paths depend on the current working directory, so the same argument can resolve to different files across processes or even within the same process if state changes. Symbolic links and mount namespaces add another layer of indirection, which means two identical-looking syscalls may touch different endpoints. Those differences are operationally important when you are reconstructing behavior.
TOCTOU conditions make the problem worse because the object checked and the object used are not guaranteed to be the same. A monitor that records only the argument string may conclude that a benign file was accessed when the kernel actually operated on a different target. In practice, this can weaken correlation, enrichment, and alert triage.
What higher-fidelity monitoring needs to capture
Effective Linux detection usually needs more than the argument list. Kernel-observed context such as resolved paths, inode or object identity, namespace context, and the before/after relationship between open, rename, exec, and follow-on operations gives a truer picture of activity. That is what lets analysts distinguish a harmless lookup from a meaningful access path.
This is especially important when you are looking for persistence, evasion, or suspicious file access patterns. A process may use an argument that looks routine while the real execution path lands on a sensitive location through resolution rules or a race. The detection value comes from reconstructing the actual object chain, not just the initial API surface.
Risk and Threat Considerations
Argument-only monitoring creates exposure because it can be bypassed through ordinary filesystem semantics rather than exotic malware. Attackers can exploit resolution differences, timing windows, and indirection to make one object appear in telemetry while another is actually used.
Failure mechanism: The monitor trusts the syscall input string as if it were the authoritative target, but the kernel may resolve that input into a different object after symlink traversal, namespace lookup, or a race between check and use. The detection pipeline then correlates on the wrong asset or misses the real action entirely.
Impact: Analysts can miss malicious file execution, misclassify sensitive access, or fail to connect related events across a sequence. Over time, that reduces confidence in host telemetry and creates blind spots in alerting and forensic reconstruction.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while CIS Controls v8, NIST SP 800-53 Rev 5 and OWASP ASVS set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| MITRE ATT&CK | T1005 — Data from Local System | Path and file access monitoring depend on accurate host event reconstruction. |
| Recommendation — Correlate file events with resolved object context before flagging suspicious access. | ||
| CIS Controls v8 | CIS-8 — Audit Log Management | Syscall telemetry quality affects whether logs support reliable detection and investigation. |
| Recommendation — Collect host telemetry with enough context to reconstruct the true accessed object. | ||
| NIST SP 800-53 Rev 5 | AU-2 — Event Logging | Detection quality depends on logging events with the context needed to interpret host actions. |
| SI-4 — System Monitoring | Monitoring must account for resolution and race conditions to detect the real execution path. | |
| Recommendation — Log host events with resolved targets and related context needed for analysis. Monitor system activity using context that reflects the kernel's actual operation. | ||
| OWASP ASVS | V16 — Security Logging and Error Handling | The core issue is log fidelity, where raw inputs can differ from authoritative execution results. |
| Recommendation — Capture security-relevant runtime context rather than relying on input strings alone. | ||
Practitioner Guidance
What to verify: Treat syscall arguments as a starting point, then confirm the kernel-resolved target and the execution context that produced it. For file activity, the most useful evidence is the resolved object identity and the sequence of related operations, not just the original string.
Common mistake: Teams often overfit detection logic to path text because it is easy to parse and search. That is acceptable for rough filtering, but it is not sufficient for high-confidence alerting when symlinks, relative paths, namespaces, or races can change the true target.
Practitioner takeaway: The best Linux monitoring assumes the argument is provisional until the kernel has resolved it, because detection quality depends on the object actually touched, not the one the process claimed to touch.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on September 26, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
