Linux KernelOperating system · Linux
CVE-2024-43856
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: dma: fix call order in dmam_free_coherent dmam_free_coherent() frees a DMA allocation, which makes the freed vaddr available for reuse, then calls devres_destroy() to remove and free the data structure used to track the DMA allocation. Between the two calls, it is possible for a concurrent task to make an allocation with the same vaddr and add it to the devres list. If this happens, there will be two entries in the devres list with the same vaddr and devres_destroy() can free the wrong entry, triggering the WARN_ON() in dmam_match. Fix by destroying the devres entry before freeing the DMA allocation. kokonut //net/encryption http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03
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 analysisThe application allocates memory, connections, or handles in response to a request without enforcing any cap, so a modest amount of malicious traffic exhausts the resource and denies service to everyone else. The fix is enforcing quotas, limits, and timeouts on what any single request or client can consume.
General guidance for the resource allocation without limits 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
>= 2.6.21, < 4.19.320>= 4.20, < 5.4.282>= 5.5, < 5.10.224>= 5.11, < 5.15.165>= 5.16, < 6.1.103>= 6.2, < 6.6.44>= 6.7, < 6.10.3CVSS 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 · scoped4.19.3205.4.2825.10.224
Upgrade to kernel version 4.19.320+ (for 4.19.x base), 5.4.282+ (for 5.4.x base), 5.10.224+ (for 5.10.x base), or 5.15.165+ (for 5.15.x base)
- Identify the current kernel version using `uname -r` or `cat /proc/version`
- Download or obtain the kernel source for your current version from https://www.kernel.org/
- Apply the fix by modifying the `dmam_free_coherent` function in the appropriate DMA-related source file (typically in `lib/dma-debug.c` or similar DMA management code)
- The fix involves reordering the calls: call `devres_destroy()` BEFORE `dma_free_coherent()` instead of after
- Alternatively, if your distribution provides kernel updates, upgrade to version 4.19.320 or higher, 5.4.282 or higher, 5.10.224 or higher, or 5.15.165 or higher depending on your base version
- Reboot into the patched/updated kernel and verify the fix resolves the race condition
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-43856 — 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-2024-43856 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
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- Version or environment caveats, and links to real fixes
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