medium CVSS 5.5 EPSS <0.1%

CVE-2021-47423·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau/debugfs: fix file release memory leak When using single_open() for opening, single_release() should be called, otherwise the 'op' allocated in single_open() will be leaked.

Severity
medium
Software
Kernel
Fixed in
5.14.12
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 6% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Affected versions

From: 5.11

Until: 5.14.12

Fixed in: 5.14.12

How to fix this CVE

Update your Linux kernel to version 5.14.12 or later to resolve a memory leak in the nouveau GPU driver's debugfs interface. The vulnerability occurs when the debugfs file release handler fails to properly deallocate memory allocated during file open operations, potentially causing kernel memory exhaustion over time. Apply the patch immediately to prevent denial-of-service conditions from accumulated memory leaks.

sudo dnf update kernel kernel-devel kernel-headers

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed kernel version: uname -r (vulnerable if between 5.11 and 5.14.11)
  2. Verify nouveau driver is loaded: lsmod | grep nouveau (if output is empty, component is not exposed)
  3. Check for debugfs nouveau access in audit logs: ausearch -m open -F dir=/sys/kernel/debug/dri -ts recent
  4. Confirm kernel update applied: uname -r should show 5.14.12 or later

FAQ

What is CVE-2021-47423?

This is a memory leak vulnerability in the Linux kernel's nouveau GPU driver debugfs implementation where the file release handler fails to call the proper cleanup function, causing allocated memory structures to persist indefinitely.

Is CVE-2021-47423 being actively exploited?

No, this vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog and no public exploits are available. However, the memory leak can be reliably triggered by repeatedly accessing debugfs files.

What versions of Kernel are affected by CVE-2021-47423?

Linux kernel versions 5.11 through 5.14.11 are affected. Version 5.14.12 and later contain the fix.

How do I check if my server is vulnerable to CVE-2021-47423?

Run 'uname -r' to check your kernel version. If it shows 5.11 to 5.14.11 and 'lsmod | grep nouveau' returns output, your system is vulnerable.

Does Defensia detect CVE-2021-47423?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2021-47423 will appear in your dashboard with remediation steps.

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References

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