* [CVE-2026-98732][MODERATE REGULAR] Bluetooth: btintel: fix buffer over-read in btintel_hw_error()
@ 2026-10-19 5:38 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-10-19 5:38 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-98732
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: Bluetooth: btintel: fix buffer over-read in btintel_hw_error()
Commit: bbc7de352f3f3864369c904aac944c7de84c6e7b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bbc7de352f3f3864369c904aac944c7de84c6e7b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98732
Analysis date: Mon, 19 Oct 2026 01:38:04 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate
Manual review required: NO
Summary:
A non-NUL-terminated Intel Bluetooth exception payload can make btintel_hw_error read and log bytes beyond the skb payload, causing limited information exposure and a less likely kernel fault.
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ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98732 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98732
The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.
This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.
The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.
Published priority for this report: MODERATE REGULAR
Manual review required: NO
A detailed explanation of the methodology and priority rules is included
at the end of this message.
======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================
CVE-2026-98732 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98732 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=1 LEGACY=MODERATE RESULT=DIFF V39_AEGIS_ONE_STEP_UP=LOW->MODERATE TEMP_DISTANCE_MERGE_SKIP=AEGIS_NO_POSITIVE_SEVERITY_EVIDENCE (final Legacy and Aegis differ; FINAL: MODERATE, Aegis: MODERATE_KPANIC) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H';CWE-126;CWE-125;CWE-170;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N';BEST CVSS score: '5.3';DESCR 'A buffer over-read occurs in btintel_hw_error because a fixed length Bluetooth exception payload is passed to the percent s formatter even though it is not guaranteed to be NULL-terminated. The kernel can continue reading beyond the end of the skb payload until a zero byte is found and may expose adjacent kernel data through the kernel log. In a less likely case the invalid read may cross an unsafe memory boundary and cause a kernel fault or crash. For the CVSS the PR:L value is used because a local process and permitted access to the Bluetooth interface are expected for practical triggering. AC:H reflects the additional requirement to provoke an Intel controller hardware error with a payload that lacks an early zero byte. The issue is not proven to be remotely reachable from an ordinary Bluetooth peer because the vulnerable path processes controller exception information rather than normal peer supplied packet data. Impact is primarily limited information disclosure and the paranoid case includes denial of service. No write primitive or direct privilege escalation path is established. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 5.3 and the production ActionableScore returned 2 with recommendation Ordinary Moderate. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were final reconciliation stage LOW to MODERATE because KP specialist did not establish a qualifying panic and the cross model evidence reconciliation rule was applied. The legacy KP specialist has no review artifact for this run. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were KPANIC_UNSUPPORTED_REMOVED and V39_AEGIS_ONE_STEP_UP and MANUAL_REVIEW_REQUIRED. The independent weaker Aegis shadow evaluated CVSS 2.0 and ActionableScore 1 with primitive class CLASS_C and manual review RECOMMENDED. Its independently reconciled impact was MODERATE_KPANIC. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is MODERATE.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) MAYBE SIMPLEFIX ERRORPATH SKB HARDWARE LINUS KPANIC_UNSUPPORTED_REMOVED V39_AEGIS_ONE_STEP_UP MANUAL_REVIEW_REQUIRED - - checked
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ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO
1. ActionableScore
* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 2
* Paranoid score: 2
* No floor or cap applied.
* Final recommended bucket: **Ordinary Moderate**::
2. Signal breakdown
Conservative signals:
* +1 Confidentiality plausible. The unbounded percent s conversion reads beyond the non-NUL-terminated payload and emits the resulting bytes to the kernel log, providing a concrete disclosure sink.
* +0 Weak corruption concern. This is a read-only overrun with no write, UAF, refcount mutation, or control-flow primitive.
Paranoid additional signal:
* +1 Potential strong DoS. An unbounded kernel string read could cross an inaccessible memory boundary and fault, although no crash is demonstrated by the patch.
Not awarded:
* No remote-reachability point. Ordinary Bluetooth traffic is not shown to control the Intel controller exception response.
* No firmware-mediated point. Controller mediation is established, but attacker influence over the controller response is not.
* No integrity or LPE point. There is no write primitive, active-state corruption, authorization bypass, or lifetime violation.
* No broad-exposure point. Intel Bluetooth is common, but this hardware-error response path is exceptional.
* B5-R is inapplicable because there is no heap OOB write or retry-accumulated offset.
* B3-PENDING is inapplicable because no shared-backing write exists.
* B4-PENDING is inapplicable because no authorization decision changes from DENY to ALLOW.
Arithmetic:
* Conservative: confidentiality disclosure path +1 = 1.
* Paranoid: confidentiality +1 and possible kernel fault +1 = 2.
3. Reachability analysis
The payload originates from an Intel Bluetooth controller response processed by `btintel_hw_error()`. The supplied evidence does not establish that an ordinary nearby Bluetooth peer can directly trigger the hardware error or control the exception bytes.
A local process may be able to exercise Bluetooth interfaces, but the complete sequence required to provoke this vendor-specific hardware-error response is unresolved. Host-administrator privilege is therefore not positively required or excluded. No evidence establishes that the complete trigger is available through attacker-created user or network namespaces. Intel Bluetooth hardware and the affected driver are prerequisites, but the hardware is not shown to be rare.
There is no race. Exploitation instead depends on reaching the hardware-error path, receiving a payload without an early NUL byte, and potentially gaining access to the resulting kernel log output.
4. Primitive and severity interpretation
The exact primitive is an unbounded heap-buffer over-read caused by treating `skb->data + 1` as a NUL-terminated string. Adjacent bytes can be consumed by the formatting operation and written to the kernel log.
This is not active structured-state corruption, a UAF, a shared-backing write, or an authorization bypass. The demonstrated consequence is unintended reading and logging beyond the payload boundary. A kernel fault is technically possible but not demonstrated. No useful write, controlled target, privilege-escalation mechanism, or security-boundary transition is established.
`PrimitiveClass=CLASS_C` is appropriate because the issue provides a limited invalid-read and possible crash primitive rather than active corruption. `ImportantCandidate=NO` follows from the absence of a write, lifetime violation, substantial disclosure, or boundary bypass. `AutoDowngradeAllowed=YES` is appropriate, although manual confirmation of triggerability and log visibility is recommended.
5. One-sentence report phrase
A non-NUL-terminated Intel Bluetooth exception payload can make btintel_hw_error read and log bytes beyond the skb payload, causing limited information exposure and a less likely kernel fault.
6. Manual review recommendation
MANUAL CHECK RECOMMENDED
Confirm whether an untrusted local or nearby actor can provoke the Intel hardware-error response and whether the resulting adjacent bytes are observable through kernel logs in the evaluated product.
7. Call-site confidence
Call-site confidence: medium
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: Bluetooth: btintel: fix buffer over-read in btintel_hw_error()
Commit: bbc7de352f3f3864369c904aac944c7de84c6e7b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bbc7de352f3f3864369c904aac944c7de84c6e7b
Commit description:
The "Exception info %s" print uses skb->data + 1, but the 12-byte
payload is not guaranteed to be NUL-terminated and can be read past
its end.
Bound the print with "%.*s" and skb->len - 1.
Fixes: 973bb97 ("Bluetooth: btintel: Add generic function for handling hardware errors")
Cc: [email protected]
Signed-off-by: Chandrashekar Devegowda <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Changed files:
drivers/bluetooth/btintel.c
Diff excerpt:
Not included in this email. See the upstream URL for the full patch.
Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bbc7de352f3f3864369c904aac944c7de84c6e7b
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98732 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98732
The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.
The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.
This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.
The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.
Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:
Conservative CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H
The Best / paranoid CVSS score: 5.3
The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.
CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.
A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.
Conservative ActionableScore: 1
Paranoid ActionableScore: 2
The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.
For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:
ActionableScore below 5 -> MODERATE REGULAR
ActionableScore 5 or more -> MODERATE 7.0
The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.
There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).
KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.
AL-KERNEL base severity for this report: MODERATE
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): MODERATE REGULAR
These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).
Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is [email protected] (and both
send reply to CVE record itself too and see "reply" button below for howto reply).
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