Summary
In the Linux kernel, the following vulnerability has been resolved: s390/cio: fix out-of-bounds...
In the Linux kernel, the following vulnerability has been resolved:
s390/cio: fix out-of-bounds access on cio_ignore free
The channel-subsystem-driver scans for newly available devices whenever
device-IDs are removed from the cio_ignore list using a command such as:
echo free >/proc/cio_ignore
Since an I/O device scan might interfer with running I/Os, commit
172da89ed0ea ("s390/cio: avoid excessive path-verification requests")
introduced an optimization to exclude online devices from the scan.
The newly added check for online devices incorrectly assumes that
an I/O-subchannel's drvdata points to a struct io_subchannel_private.
For devices that are bound to a non-default I/O subchannel driver, such
as the vfio_ccw driver, this results in an out-of-bounds read access
during each scan.
Fix this by changing the scan logic to rely on a driver-independent
online indication. For this we can use struct subchannel->config.ena,
which is the driver's requested subchannel-enabled state. Since I/Os
can only be started on enabled subchannels, this matches the intent
of the original optimization of not scanning devices where I/O might
be running.
Impact
A read operation accesses a memory location beyond the intended buffer boundary. Typical impact: sensitive data disclosure or crash.
CVE-2022-50307 has a CVSS score of 7.1 (High). 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-2022-50307? CVE-2022-50307 is a high-severity out-of-bounds read vulnerability. No fixed version is listed yet. A read operation accesses a memory location beyond the intended buffer boundary.
- How severe is CVE-2022-50307? CVE-2022-50307 has a CVSS score of 7.1 (High). 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-2022-50307? No fixed version is listed for CVE-2022-50307 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2022-50307 exploitable, and should I be worried? Whether CVE-2022-50307 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-2022-50307 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.