Linux KernelOperating system · Linux
CVE-2016-8440
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 · uneditedPossible buffer overflow in SMMU system call. Improper input validation in ADSP SID2CB system call may result in hypervisor memory overwrite. Product: Android. Versions: Kernel 3.18. Android ID: A-31625306. References: QC-CR#1036747.
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 analysis · moderate confidenceA buffer overflow vulnerability exists in the SMMU (System Memory Management Unit) system call within Android kernel 3.18. The ADSP SID2CB system call lacks proper input validation, allowing an attacker to potentially overwrite hypervisor memory through this privilege-escalation vector.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
= 3.18CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the running kernel versionRun 'uname -r' or check /proc/version to obtain the exact kernel versionAffected if The kernel version is exactly 3.18 (not a later or earlier version)
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Verify SMMU driver is presentCheck for SMMU-related kernel modules or configuration: lsmod | grep -i smmu or check /boot/config-$(uname -r) for CONFIG_ARM_SMMU or similar SMMU optionsAffected if The SMMU driver is compiled as a module or built-in kernel support
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Confirm ADSP subsystem is enabledCheck kernel config for ADSP-related options (CONFIG_MSM_ADSPRPC or similar) or verify the ADSP device node exists at /dev/adsprpc-smd or /dev/qcom_adspAffected if The ADSP subsystem is present and accessible on the device
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Identify SMMU system call availabilityExamine /sys/kernel/debug/smmu or similar debugfs entries, or check for SMMU device files in /dev/ that expose the system call interfaceAffected if The SMMU system call interface is exposed to userspace applications
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Verify the device is Android-basedCheck /system/build.prop or run 'getprop ro.build.version.sdk' to confirm Android environmentAffected if The device runs Android with kernel 3.18, as this is Android-specific
A device is affected if it runs Android kernel 3.18 exactly, has SMMU support enabled, and exposes the ADSP SID2CB system call interface to userspace.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataImplement rigorous input validation and bounds checking in the ADSP SID2CB system call to prevent buffer overflows. Apply vendor-provided kernel patches for Android and ensure hypervisor memory boundaries are properly enforced.
Fix this in Linux Kernel
Scoped from the published advisory
- Consultation6.0 h
- Implementation12.0 h
- Testing10.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,504.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-8440 — 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-2016-8440 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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