* [CVE-2026-89848][MODERATE 7.0] scsi: qla2xxx: Quiesce response IRQ before freeing request queue
@ 2026-09-16 19:16 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-09-16 19:16 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-89848
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: scsi: qla2xxx: Quiesce response IRQ before freeing request queue
Commit: 7ac5be2a8609679fc6bbfea881360444a5ce8202
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7ac5be2a8609679fc6bbfea881360444a5ce8202
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89848
Analysis date: Wed, 16 Sep 2026 15:16:47 -0400
ActionableScore: 5
ActionableScore lower bound: 4
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-89848 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89848
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-2026-89848 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-89848 CHECK WITH IMPACT FROM ORIG NN LOW Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H';*CWE-416;CWE-362;CWE-667;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7.5';DESCR 'A use-after-free race in the qla2xxx teardown path can occur because qla2xxx_delete_qpair deletes the request queue before the response queue IRQ is quiesced. During this window a late response MSI-X interrupt can queue qpair q_work, and qla_do_work can process the response queue while rsp req still points to request queue memory that has already been freed. For the CVSS the PR:N is used for the paranoid network adjacent scenario because an attacker that controls or impersonates a Fibre Channel peer may not need a local account on the host, although reliable triggering still depends on hitting the teardown or reset timing window. The issue is not reachable from ordinary IP networks and normally applies to hosts with affected QLogic Fibre Channel hardware and an exposed or attacker influenced storage fabric. Impact is at least denial of service via kernel crash and in worst case may allow broader confidentiality or integrity impact due to kernel use-after-free memory corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5) YES INIT UAF DMAorINTERRUPT HARDWARE LINUS KPANIC KPANIC INCREASED_TO_MODERATE7_BASED_ON_GUESSCVSS NO NO checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=5
ActionableScoreLower=4
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
1. ActionableScore
* Raw conservative score: 2
* Conservative score: 4
* Applied conservative floor: 2 -> 4 because a real active-object kernel UAF is established and host-admin-only reachability is not positively proven.
* Raw paranoid score: 3
* Paranoid score: 5
* Applied paranoid floor: 3 -> 5 because the stale pointer is consumed by nontrivial response-queue processing, not only by a shallow cleanup fault, and storage-fabric timing may influence late completions.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::
2. Signal breakdown
Positive signals:
* +2 Real UAF / active lifetime violation. The request queue is freed by qla25xx_delete_req_que(), while rsp->req can still be reached by a late response interrupt and queued qpair work.
* +1 Reliable kernel crash / strong DoS. The stale rsp->req dereference in qla_do_work() -> qla24xx_process_response_queue() can fault or crash the kernel.
* +1 paranoid firmware-mediated external influence. A Fibre Channel peer or storage-fabric condition may influence completions and response IRQ timing, but this is mediated by hardware, firmware, and driver state rather than ordinary IP network input.
Negative signals:
* -1 hard timing / teardown window. The stale use depends on a late response IRQ or queued work occurring after request-queue free and before response-queue IRQ quiescence.
Important non-awarded signals:
* Controlled reclaim not demonstrated.
* Arbitrary read/write not demonstrated.
* Direct remote IP network reachability not established.
* Strong LPE leverage not awarded because no attacker-shaped replacement object, callback control, or directed corruption is shown.
* Structured stale-object leverage is not separately awarded because attacker control over replacement or consumed post-free contents is not established.
* Extra Availability is not awarded because the same kernel crash is already counted.
* Confidentiality and Integrity are not awarded as positive ActionableScore signals merely because a UAF could theoretically corrupt reused memory.
* Concrete repeated release/refcount signal is not awarded. The first lifetime operation can free req, and the stale reference survives, but the later operation is a dereference/response processing path, not a second put/release/refcount mutation on the exact same reference.
* FLOOR 5 is applied only for the paranoid score, not because UAF automatically implies LPE, but because the stale request queue is used in active response handling and the storage-fabric influence remains unresolved.
3. Reachability analysis
The vulnerable sequence occurs during qpair teardown in the qla2xxx Fibre Channel SCSI driver. A local host administrator can likely trigger relevant teardown, reset, or driver-management paths, but the supplied evidence does not positively prove that host-admin-equivalent privilege is always required for the complete vulnerable sequence.
A remote ordinary IP attacker cannot directly reach this path. The plausible external influence is network-adjacent storage-fabric input or timing through Fibre Channel completions and MSI-X response interrupts. This is firmware/device-mediated rather than direct socket/network reachability.
Namespace-scoped privilege is not applicable based on the supplied context. This is a physical Fibre Channel driver path, not a network namespace, user namespace, or container-local control-plane object.
Special hardware is required in the practical sense that affected QLogic Fibre Channel hardware and the qla2xxx driver path must be present. I did not apply a rare-hardware penalty because the prompt requires concrete evidence before using such a reducing signal, and enterprise Fibre Channel adapters are specialized but not enough by itself to erase a real kernel UAF.
Race repeatability is uncertain. The bug requires a teardown window plus a late response interrupt or pending work item, so timing is meaningful and receives one reducing point.
4. Primitive and severity interpretation
The exact primitive is a use-after-free of the request queue referenced through rsp->req. The stale object is active structured kernel state used by qla24xx_process_response_queue(), including paths for LOGINOUT, CT, ELS, and status processing.
This is not fixed stale storage like a simple DMA buffer. It is also not merely a second cleanup put/free operation. The important operation after free is active response processing through a stale request-queue reference.
PrimitiveClass is CLASS_B. A concrete kernel lifetime violation exists, but the evidence does not establish controlled reclaim, attacker-selected replacement contents, arbitrary write, callback hijack, information disclosure, or demonstrated privilege escalation.
The demonstrated consequence is kernel crash / DoS. The speculative consequence is broader memory corruption impact from processing a freed structured object, but that remains unresolved and requires manual review.
ImportantCandidate is YES because this is an active-object UAF in an interrupt/workqueue driver path with unresolved storage-fabric influence and nontrivial stale processing. AutoDowngradeAllowed is NO because automatically treating it as ordinary crash-only cleanup would risk losing a real unresolved lifetime-corruption primitive.
Likely operational severity is Actionable Moderate, with Important review justified. It is not a confirmed Strong Important case without stronger evidence of controlled reuse, corruption beyond crash, or below-host-admin reliable triggering.
5. One-sentence report phrase
A qla2xxx teardown race can leave the response IRQ active after the request queue is freed, allowing late response work to dereference stale rsp req state and crash the kernel, with broader UAF exploitation impact unresolved.
6. Manual review recommendation
MANUAL CHECK REQUIRED
Reason: this is a real kernel UAF in active response-queue processing, not just a harmless warning or resource leak, and the complete storage-fabric reachability and post-free exploitation leverage are unresolved.
7. Call-site confidence
Call-site confidence: high
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: scsi: qla2xxx: Quiesce response IRQ before freeing request queue
Commit: 7ac5be2a8609679fc6bbfea881360444a5ce8202
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7ac5be2a8609679fc6bbfea881360444a5ce8202
Commit description:
qla2xxx_delete_qpair() deletes the request queue before the response
queue. qla25xx_delete_req_que() frees the request queue memory
(kfree(req) in qla25xx_free_req_que()), but the response-queue MSI-X is
only released later, in qla25xx_free_rsp_que(). In that window the
response interrupt can still fire, qla2xxx_msix_rsp_q() queues
qpair->q_work, and qla_do_work() -> qla24xx_process_response_queue()
dereferences the now-freed rsp->req (LOGINOUT/CT/ELS entries and the
status path), a use-after-free.
The cancel_work_sync() added for the qpair teardown lives in the
response free path, which runs after the request queue is already freed,
so it does not protect rsp->req.
Release the response-queue interrupt and flush qpair->q_work before
deleting the request queue, so no late completion can reach the freed
request queue. Clearing have_irq makes the subsequent
qla25xx_free_rsp_que() skip its free_irq(), and the firmware
queue-delete order (request then response) is preserved; the
request-delete mailbox completes on the default vector and is unaffected
by dropping the qpair response interrupt early.
Fixes: d745952 ("scsi: qla2xxx: Add multiple queue pair functionality.")
Cc: [email protected]
Reported-by: Sashiko <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Martin K. Petersen (Oracle) <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Changed files:
drivers/scsi/qla2xxx/qla_init.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=7ac5be2a8609679fc6bbfea881360444a5ce8202
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-89848 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-89848
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:H
The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
The Best / paranoid CVSS score: 7.5
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: 4
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).
^ permalink raw reply [relevance 21%]
Results 1-1 of 1 | reverse | sort options + mbox downloads above
-- links below jump to the message on this page --
2026-09-16 19:16 21% [CVE-2026-89848][MODERATE 7.0] scsi: qla2xxx: Quiesce response IRQ before freeing request queue AL-KERNEL
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox