Linux KernelOperating system · Linux
CVE-2021-47205
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: clk: sunxi-ng: Unregister clocks/resets when unbinding Currently, unbinding a CCU driver unmaps the device's MMIO region, while leaving its clocks/resets and their providers registered. This can cause a page fault later when some clock operation tries to perform MMIO. Fix this by separating the CCU initialization from the memory allocation, and then using a devres callback to unregister the clocks and resets. This also fixes a memory leak of the `struct ccu_reset`, and uses the correct owner (the specific platform driver) for the clocks and resets. Early OF clock providers are never unregistered, and limited error handling is possible, so they are mostly unchanged. The error reporting is made more consistent by moving the message inside of_sunxi_ccu_probe.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisAllocated memory is never released on some path, so a long-running service or a repeatedly triggered request steadily consumes memory until performance degrades or the process crashes. Attackers exploit it by simply driving the leaking path. Remediation is pairing every allocation with a release and using ownership patterns or tooling to catch what leaks.
General guidance for the memory leak class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
< 5.15.5CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.15.5
Linux Kernel 5.15.5 or later stable release
- Identify the current Linux kernel version running on affected systems using 'uname -r' or 'cat /proc/version'
- Download or obtain Linux kernel 5.15.5 or a later stable release from kernel.org or your distribution's package repositories
- Apply the kernel upgrade following your distribution's standard kernel update procedure (e.g., 'apt-get dist-upgrade', 'yum update', or compiling from source)
- Reboot systems into the new kernel version
- Verify the fix is applied by checking the kernel version with 'uname -r' and confirming it is >= 5.15.5
- For embedded/custom systems using the sunxi-ng CCU driver, ensure the device tree or board configuration does not conflict with the updated driver
Generated from the published advisory — verify against the referenced sources before acting.
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Free · runs locallyCheck whether your project pulls in CVE-2021-47205 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-47205 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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