* [CVE-2026-98605][MODERATE 7.0] drm/bridge: samsung-dsim: fix TE GPIO lifetime for host attach [ Upstream
@ 2026-10-24 13:39 21% AL-KERNEL
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From: AL-KERNEL @ 2026-10-24 13:39 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-98605
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: drm/bridge: samsung-dsim: fix TE GPIO lifetime for host attach [ Upstream
Commit: 77a43e00c57486a5212ef22d4665cafad62a5d4b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=77a43e00c57486a5212ef22d4665cafad62a5d4b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98605
Analysis date: Sat, 24 Oct 2026 09:39:44 -0400
ActionableScore: 5
ActionableScore lower bound: unknown
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES
Summary:
A managed TE GPIO descriptor is explicitly released while its devres release action remains registered, allowing a later second release of the same potentially dead descriptor.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98605 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98605
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 7.0
Manual review required: YES
A detailed explanation of the methodology and priority rules is included
at the end of this message.
======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================
CVE-2026-98605 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98605 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=3 LEGACY=MODERATE_KPANIC RESULT=SAME (final reconciliation agrees; DECISION: both 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:N/I:N/A:L';*CWE-664;CWE-675;*CWE-672;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '2.5';DESCR 'The Samsung DSIM host attach path acquired the TE GPIO as a managed resource while its error and detach paths explicitly released the same descriptor. Host detach and reattach can leave stale managed release actions associated with the device and later cause duplicate GPIO release attempts or prevent reliable TE IRQ registration. For the CVSS the PR:L paranoid value reflects environments where a local service or reduced capability process can control display host lifecycle operations. The usual trigger still requires local device management and a specific attach detach and teardown sequence. The supported impact is limited availability loss for the display path. There is no concrete UAF dereference OOB access or arbitrary write primitive supporting confidentiality integrity or privilege escalation impact. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 2.5 and the production ActionableScore returned 5 with recommendation Actionable Moderate / Strong Important candidate requiring manual review. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were ActionableScore thresholds stage LOW to MODERATE_KPANIC because the ActionableScore threshold rule was applied. The legacy KP specialist produced a review artifact and its decision was processed by the applicable KP rules. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were INCREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN5. The independent weaker Aegis shadow evaluated CVSS 2.5 and ActionableScore 3 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE_KPANIC.';NO MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5) MAYBE SIMPLEFIX ERRORPATH HARDWARE LINUS KPANIC INCREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN5 - - checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=5
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO
1. ActionableScore
* Raw base score: 4.
* Conservative score: 5. REAL UAF FLOOR 5 applies because the managed GPIO release action survives an explicit release and can later perform a second lifetime-affecting release on the same descriptor.
* Raw paranoid score: 5.
* Paranoid score: 5. No additional floor or cap.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::
2. Signal breakdown
* +2 Real lifetime violation: `devm_gpiod_get_optional()` registers a device-managed release, while explicit `gpiod_put()` releases the same descriptor during detach or IRQ-registration failure.
* +1 Concrete repeated release: the first `gpiod_put()` may end the descriptor lifetime, but the devres action remains and can later release that exact descriptor during device teardown.
* +1 Availability impact: detach/reattach can prevent reliable TE IRQ registration and disrupt the display path; host panic is not shown.
* Paranoid +1: the eventual managed release is a write-like lifetime mutation through storage whose original descriptor lifetime may already have ended. This is scored only in the paranoid arithmetic before the common floor.
* Controlled reclaim, attacker-shaped replacement data, arbitrary write, callback control, disclosure, and LPE are not shown.
* No extra crash/availability point is awarded; kernel panic is unsupported.
* B5-R, B3-PENDING, and B4-PENDING do not apply.
3. Reachability analysis
The sequence requires Samsung DSIM host attach, detach or an IRQ-registration failure, and eventual reattach or device teardown. The supplied evidence does not establish whether a normal user, DRM master, compositor, delegated display service, or only a host administrator can drive the complete lifecycle. Therefore host-admin and UID-0 requirements remain unknown. No namespace-scoped capability path, special timing race, or attacker-controlled retry sequence is shown. Samsung DSIM hardware is required, but the evidence does not establish that it is sufficiently rare to justify a hardware penalty.
4. Primitive and severity reading
This is an active, lifetime-managed GPIO descriptor rather than a fixed stale buffer. It is stronger than an ordinary cleanup dereference:
A. No mere stale field read or immediate fault is demonstrated.
B. An explicit release can end the descriptor lifetime while a registered managed action survives and later performs another release on the same descriptor.
That is CLASS_B repeated lifetime corruption, not CLASS_A: post-free mutation is credible, but controlled reuse or a directed corruption target is absent. Important status is unproven, yet the concrete second lifetime operation leaves enough unknown leverage to require review and prohibit automatic downgrade.
5. One-sentence report phrase
A managed TE GPIO descriptor is explicitly released while its devres release action remains registered, allowing a later second release of the same potentially dead descriptor.
6. Manual review advice
MANUAL CHECK REQUIRED
Confirm GPIO descriptor destruction semantics, devres teardown ordering, complete display-lifecycle permissions, and whether the delayed second release can mutate reused storage rather than only causing device-local failure.
7. Call-site confidence
Call-site confidence: medium
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: drm/bridge: samsung-dsim: fix TE GPIO lifetime for host attach [ Upstream
Commit: 77a43e00c57486a5212ef22d4665cafad62a5d4b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=77a43e00c57486a5212ef22d4665cafad62a5d4b
Changed files:
drivers/gpu/drm/bridge/samsung-dsim.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=77a43e00c57486a5212ef22d4665cafad62a5d4b
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98605 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98605
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:H/UI:N/S:U/C:N/I:N/A:L
The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
The Best / paranoid CVSS score: 2.5
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: unknown
Paranoid ActionableScore: 5
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: YES
Published priority for this report (same as in Subject): MODERATE 7.0
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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