Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: clean up potential...
In the Linux kernel, the following vulnerability has been resolved:
nfsd: clean up potential nfsd_file refcount leaks in COPY codepath
There are two different flavors of the nfsd4_copy struct. One is
embedded in the compound and is used directly in synchronous copies. The
other is dynamically allocated, refcounted and tracked in the client
struture. For the embedded one, the cleanup just involves releasing any
nfsd_files held on its behalf. For the async one, the cleanup is a bit
more involved, and we need to dequeue it from lists, unhash it, etc.
There is at least one potential refcount leak in this code now. If the
kthread_create call fails, then both the src and dst nfsd_files in the
original nfsd4_copy object are leaked.
The cleanup in this codepath is also sort of weird. In the async copy
case, we'll have up to four nfsd_file references (src and dst for both
flavors of copy structure). They are both put at the end of
nfsd4_do_async_copy, even though the ones held on behalf of the embedded
one outlive that structure.
Change it so that we always clean up the nfsd_file refs held by the
embedded copy structure before nfsd4_copy returns. Rework
cleanup_async_copy to handle both inter and intra copies. Eliminate
nfsd4_cleanup_intra_ssc since it now becomes a no-op.
Impact
CVE-2023-53606 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2023-53606? CVE-2023-53606 is a medium-severity security vulnerability. No fixed version is listed yet.
- How severe is CVE-2023-53606? CVE-2023-53606 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2023-53606? No fixed version is listed for CVE-2023-53606 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2023-53606 exploitable, and should I be worried? Whether CVE-2023-53606 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-53606 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.