* [CVE-2026-89625][MODERATE 7.0] HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind
@ 2026-09-11 23:41 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-09-11 23:41 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-89625
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind
Commit: 114a58640aaf3c2eb97b5b01c75ab5e541d15d9c
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=114a58640aaf3c2eb97b5b01c75ab5e541d15d9c
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89625
Analysis date: Fri, 11 Sep 2026 19:41:49 -0400
ActionableScore: 4
ActionableScore lower bound: unknown
Actionable bucket: Borderline / manual review recommended
Manual review required: YES
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-89625 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89625
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-2026-89625 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-89625 CHECK WITH IMPACT FROM ORIG NN IMPORTANT Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H';*CWE-416;CWE-362;*CWE-672;Other CVSS 'AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '6.4';DESCR 'A use-after-free can occur in the HID Sony GHL teardown path because timer_delete_sync() does not prevent the GHL poke timer from being rearmed and usb_free_urb() does not kill an in flight URB. A URB completion can run after the timer delete step, rearm ghl_poke_timer, and later make the timer callback access the freed sony_sc object after driver unbind or device removal. For the CVSS the PR:N because a physical attacker with a controlled USB device does not need a local account on the victim, although local unbind or rmmod based triggering would normally require administrator privileges. The issue is not network reachable and requires access to the affected USB HID device path. Impact is at least denial of service via kernel crash. Because the primitive is a kernel use-after-free in a timer softirq path, worst case confidentiality and integrity impact should be reviewed manually even though practical exploitation beyond DoS is likely difficult.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 4) YES READ USB INIT RACE ERRORPATH UAF TIMER LINUS KPANIC LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS NO NO checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=4
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=NO
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
1. ActionableScore
* Raw conservative score: 4
* Conservative score: 4
* Raw paranoid score: 4
* Paranoid score: 4
* Final recommended bucket: **Borderline / manual review recommended**::
No floor or cap was applied.
2. Signal breakdown
Positive signals:
* +2 Real UAF / active lifetime violation. The timer embedded in `sony_sc` can be rearmed after `sony_remove()` returns, and the later timer callback accesses freed `sony_sc` memory.
* +1 Reliable kernel crash / strong DoS. KASAN shows `slab-use-after-free in ghl_magic_poke()` from timer softirq after the object was freed.
* +1 External physical device influence. A controlled or emulated GHL USB device can influence the URB completion timing and teardown sequence without needing host administrator privileges.
Negative or limiting signals:
* No -2 host-admin penalty. Physical device removal can reach the driver remove path without host administrator privileges, although rmmod or manual unbind would require admin.
* No -1 hard race penalty. The issue is a race, but the supplied reproducer shows the URB can be held in flight and released after teardown, so the ordering is meaningfully influenceable.
* No physical-only penalty was applied. Physical USB access is required, but USB HID exposure is a normal local attack surface and the device can be emulated.
* Controlled reclaim not demonstrated.
* Arbitrary write not demonstrated.
* Callback or function-pointer control not demonstrated.
* Concrete repeated release/refcount mutation not established. `usb_free_urb()` drops a reference, but the demonstrated stale use is the rearmed timer accessing freed `sony_sc`, not a second concrete lifetime mutation on the exact same dangling object.
* Structured stale-object leverage not awarded. The stale object is a driver context, but the demonstrated stale operation is a timer callback dereference leading to crash, with no shown attacker-shaped replacement object.
* Weak LPE not awarded solely from UAF.
* Extra Availability not awarded because the same kernel crash is already counted.
* C/I not awarded because no disclosure, controlled write, or useful post-free replacement primitive is established.
Repeated-release/refcount checklist:
* First release can end lifetime: `sony_sc` is freed after `sony_remove()` returns through devres cleanup.
* Exact same reference survives: the rearmed timer embedded in the freed `sony_sc` survives logically as a scheduled callback.
* Second operation is a real lifetime/refcount mutation: NO. The second demonstrated operation is stale timer callback execution and dereference, not a second put/free/refcount mutation.
* Concrete repeated release/refcount +1 awarded: NO.
* Paranoid repeated-refcount leverage +1 awarded: NO.
* FLOOR 5 applied: NO.
3. Reachability analysis
The realistic attacker is a physical or local-peripheral attacker with a controlled GHL-compatible USB HID device, or an attacker using USB gadget emulation in a test setup. The device can cause the driver to bind, keep the poke URB in flight, and participate in the teardown timing that lets the completion rearm the timer after `timer_delete_sync()`.
Host administrator privilege is not required for the physical-device attack model because plugging or removing a USB device can invoke probe and remove paths. However, a software-only trigger using driver unbind or rmmod would normally require administrator privilege. There is no namespace-scoped privilege path here. There is no network reachability.
Prior host setup is not required beyond having the affected HID Sony driver available and accepting the device. The affected hardware identity is specialized, but the device can be emulated with a USB gadget. The race is a disconnect/unbind teardown race, but the supplied context indicates the key ordering can be forced in testing by holding the URB in flight and releasing it after removal.
4. Primitive and severity interpretation
The exact primitive is a real kernel use-after-free: a timer callback associated with `sc->ghl_poke_timer` can execute after the containing `sony_sc` object has been freed. This is an async post-teardown lifetime bug involving a timer and URB completion callback.
This is closer to fixed async stale storage than to a strong active structured-object exploitation primitive. The stale storage is the driver context and embedded timer state. The demonstrated consequence is a KASAN UAF and likely kernel crash. There is no demonstrated controlled reclaim, no attacker-controlled replacement object, no arbitrary read/write, no information disclosure, and no privilege-escalation chain.
PrimitiveClass is CLASS_B because this is a concrete kernel lifetime violation, not just a NULL dereference or passive invalid state. ImportantCandidate is NO because the current evidence supports constrained crash/DoS behavior rather than meaningful unresolved exploitation leverage. AutoDowngradeAllowed is YES because this is a constrained async teardown UAF with demonstrated crash-only behavior and no concrete repeated refcount mutation or security-boundary primitive.
Likely operational severity is Borderline to Actionable Moderate from a kernel triage perspective, but not a strong Important candidate based on the supplied evidence.
5. One-sentence report phrase
A teardown race in the HID Sony GHL driver can let an in-flight URB completion rearm a timer after driver removal, causing the timer callback to access freed driver state and crash the kernel.
6. Manual review recommendation
MANUAL CHECK RECOMMENDED
Reason: this is a real kernel UAF in a timer softirq path, but current evidence shows a constrained physical USB teardown crash without controlled reclaim, arbitrary write, repeated refcount mutation, or privilege-escalation evidence.
7. Call-site confidence
Call-site confidence: high
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind
Commit: 114a58640aaf3c2eb97b5b01c75ab5e541d15d9c
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=114a58640aaf3c2eb97b5b01c75ab5e541d15d9c
Commit description:
For GHL (Guitar Hero Live) dongles, sony_probe() arms a periodic timer:
ghl_magic_poke() (the timer callback) submits sc->ghl_urb, and the URB
completion ghl_magic_poke_cb() re-arms the timer with mod_timer().
sony_remove() drained the timer with timer_delete_sync() and then freed
the URB with usb_free_urb():
timer_delete_sync(&sc->ghl_poke_timer);
usb_free_urb(sc->ghl_urb);
timer_delete_sync() does not block re-arming, and while the URB is in
flight the timer is not pending, so the sync delete is a no-op. A URB
completion that runs after the delete re-arms the timer, and usb_free_urb()
only drops a reference -- it does not kill an in-flight URB. sc is
allocated with devm_kzalloc() and freed once sony_remove() returns, so the
re-armed ghl_poke_timer (embedded in sc) then fires on freed memory, a
use-after-free from timer softirq. This is a disconnect/rmmod race.
Poison the URB first, then shut the timer down, before freeing the URB.
usb_poison_urb() kills any in-flight URB and permanently rejects further
submissions, so a poke timer that is still pending cannot re-submit the
URB from ghl_magic_poke() in the window before timer_shutdown_sync() runs.
usb_kill_urb() would not suffice: it only cancels the in-flight URB and
leaves it submittable once it returns, so the pending timer could
re-submit it and put a fresh URB in flight over the freed sc.
timer_shutdown_sync() then drains any last callback and blocks re-arming.
The probe error path is unaffected: it is only reached before the timer
is armed.
Reproduced under KASAN on next-20260710 via dummy_hcd + raw-gadget
emulation of the GHL PS4 dongle (VID 0x1430 / PID 0x07bb): hid-sony binds
and arms the poke timer, the poke URB is held in flight, the driver is
unbound (freeing sc), then the URB is released. The completion re-arms the
timer on the freed sc, and the re-armed timer fires ~8 s later:
BUG: KASAN: slab-use-after-free in ghl_magic_poke+0x98/0xb0
Read of size 8 at addr ffff88810b02fd50 by task swapper/0/0
ghl_magic_poke+0x98/0xb0
call_timer_fn+0x35/0x2b0
__run_timers+0x69c/0x9a0
run_timer_softirq+0x173/0x2a0
Allocated by task 169: sony_probe
Freed by task 338: devres_release_group <- hid_device_remove (sony_remove)
Found by 0sec ( https://0sec.ai ) using automated source analysis.
Fixes: cc894ac ("HID: sony: support for ghlive ps3/wii u dongles")
Cc: [email protected]
Assisted-by: 0sec:multi-model
Signed-off-by: Doruk Tan Ozturk <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Changed files:
drivers/hid/hid-sony.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=114a58640aaf3c2eb97b5b01c75ab5e541d15d9c
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-89625 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89625
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:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
The Best / paranoid CVSS vector: AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
The Best / paranoid CVSS score: 6.4
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: 4
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
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please use reply email interface to add additional manual analyses
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And please, please, let me know when you see Lows instead of Importants
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My contact email for such notifications is [email protected] (and both
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