CVE-2017-6899
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 · uneditedThe msm_bus_dbg_update_request_write function in drivers/platform/msm/msm_bus/msm_bus_dbg.c in android_kernel_huawei_msm8916 through 2017-06-16 in LineageOS, and possibly other kernels for MSM devices, allows attackers to cause a denial of service (NULL pointer dereference and device crash) via a crafted /sys/kernel/debug/msm-bus-dbg/client-data/update-request write request.
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 NULL pointer dereference vulnerability exists in the msm_bus_dbg_update_request_write function within the MSM bus debugging driver (msm_bus_dbg.c). The function fails to properly validate a pointer before dereferencing it when processing write requests to the debugfs interface at /sys/kernel/debug/msm-bus-dbg/client-data/update-request. An attacker can trigger this by sending specially crafted input, causing kernel panic and device crash.
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<= 2017-06-16CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Confirm LineageOS build dateCheck the ROM build date in Settings > About Phone > Build number or by running 'getprop ro.build.date' in a terminalAffected if Build date is on or before June 16, 2017 (2017-06-16)
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Verify MSM bus driver is presentCheck if the msm_bus debugging driver file exists by looking for msm_bus_dbg.c in /sys/kernel/debug/ or check for 'msm-bus-dbg' entry in debugfs: 'ls -la /sys/kernel/debug/msm-bus-dbg/'Affected if The debugfs directory /sys/kernel/debug/msm-bus-dbg exists and contains client-data/update-request
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Confirm vulnerable debugfs interface existsVerify the specific vulnerable path exists: 'ls -la /sys/kernel/debug/msm-bus-dbg/client-data/update-request'Affected if The file /sys/kernel/debug/msm-bus-dbg/client-data/update-request exists and is writable
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Check if device uses Qualcomm MSM SoCCheck SoC info via 'getprop ro.board.platform' or 'cat /proc/cpuinfo' to identify if the device uses a Qualcomm MSM (Mobile Station Modem) processorAffected if Device uses a Qualcomm MSM-based SoC and runs vulnerable LineageOS builds
The device is affected if it runs a LineageOS build dated on or before 2017-06-16 on a Qualcomm MSM SoC and has the msm-bus-dbg debugfs interface present and accessible.
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 dataRestrict or disable access to the msm-bus-dbg debugfs interface in production builds; apply vendor/kernel upstream patches that add proper pointer validation before use; consider disabling debugfs entirely on production devices.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-6899 — 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-2017-6899 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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