* [CVE-2026-80944][MODERATE 7.0] wifi: mwifiex: Detach sync cmd buffer on interrupted wait
@ 2026-09-11 20:12 21% AL-KERNEL
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From: AL-KERNEL @ 2026-09-11 20:12 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-80944
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: wifi: mwifiex: Detach sync cmd buffer on interrupted wait
Commit: 20ee9c03f261bf6ac59331e2ca7b46b23646412a
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=20ee9c03f261bf6ac59331e2ca7b46b23646412a
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80944
Analysis date: Fri, 11 Sep 2026 16:12:22 -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-2026-80944 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80944
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-2026-80944 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-80944 CHECK WITH IMPACT FROM ORIG NN IMPORTANT Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-416;CWE-825;*CWE-664;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'A stale stack backed buffer in mwifiex synchronous command handling can remain attached to the current command after wait_event_interruptible_timeout is interrupted. A late firmware response can then write through cmd_node data_buf after the waiting caller has returned, corrupting freed kernel stack memory and causing stack protector panic or bad pointer dereference. For the CVSS the PR:L is used for the paranoid score because a local user or local network management process may be able to trigger WiFi control plane commands and interrupt the waiting path, even though some direct operations may require CAP_NET_ADMIN in locked down deployments. The issue is not directly network reachable and is not triggered by normal packet traffic alone. Impact is at least local denial of service via kernel crash and in worst case may allow confidentiality or integrity impact due to kernel stack memory corruption, so manual review is recommended.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5) YES REMOTE OOB LOCK DANGER UAF NETWORK DEBUGFS KPANIC KPANIC DECREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCORELOWERTHAN6 NO NO checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=5
ActionableScoreLower=4
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
1. ActionableScore
* Raw conservative score: 4
* Conservative score: 4
* Raw paranoid score: 5
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::
No floor or cap changed the conservative or paranoid score.
2. Signal breakdown
Conservative positive signals:
* +2 Real UAF / lifetime violation. `cmd_node->data_buf` can point to caller-owned stack storage after the waiting caller returned.
* +1 Constrained kernel overwrite. A late firmware response can copy data through the stale `data_buf` pointer into expired kernel stack memory.
* +1 Reliable kernel crash / strong DoS. The supplied trace shows stack protector panic and bad pointer dereference.
Paranoid additional signal:
* +1 Attacker-influenced repeatable lifetime condition. The issue was observed during repeated association and disassociation cycles, and the interrupted wait plus late response sequence appears repeatable enough to require review beyond ordinary crash-only cleanup.
Non-awarded signals:
* +2 Strong exploitation leverage not awarded. No controlled reclaim, arbitrary write, callback control, or attacker-selected target is demonstrated.
* Remote reachable +2 not awarded. This is WiFi control-plane and firmware-response mediated, not normal network packet-triggered remote reachability.
* Local unprivileged trigger +1 not awarded conservatively. Below-host-admin reachability is plausible but not fully established from the supplied patch.
* Extra availability +1 not awarded. The same panic is already counted as reliable kernel crash.
* Confidentiality and integrity bonuses not awarded directly. They remain unresolved worst-case concerns from stack corruption, not demonstrated disclosure or unauthorized modification primitives.
* Concrete repeated release/refcount +1 not awarded. There is no first put/release followed by a second lifetime mutation on the same dangling reference.
* Paranoid repeated-refcount leverage not awarded.
* FLOOR 5 for repeated release/refcount not applied.
3. Reachability analysis
The likely trigger is local WiFi control-plane activity involving mwifiex synchronous commands, interruption of `wait_event_interruptible_timeout()`, and a later firmware response. Repeated association and disassociation cycles are explicitly mentioned.
Host-admin-equivalent privilege is not positively established, but complete below-host-admin reachability is also not fully proven. Some WiFi association or driver-control operations may be mediated by privileged network-management services or require `CAP_NET_ADMIN` depending on deployment. Therefore `HostAdminRequired=UNKNOWN`.
Namespace-scoped privilege is unresolved. The supplied evidence does not show that the complete WiFi device control path is available inside attacker-created namespaces.
Prior setup exists in the practical sense that affected Marvell mwifiex hardware and firmware must be present. I did not apply a rare-hardware penalty because the patch only establishes hardware specificity, not rare or physical-only attacker access.
The timing involves an interrupted wait and a late firmware response. I did not subtract a hard-race penalty because repeated association/disassociation cycles produced the corruption, suggesting the sequence is practically reproducible enough for security triage.
4. Primitive and severity interpretation
The exact primitive is an asynchronous post-lifetime write through a stale caller-owned stack buffer pointer. This is a real lifetime violation and use-after-scope style UAF.
The stale storage is a stack-backed buffer rather than a heap object with demonstrated controlled reclaim. However, the stale use is not a shallow cleanup dereference: the response path writes firmware response data into expired kernel stack memory, and the observed result is kernel stack corruption.
This is `CLASS_B`: real kernel lifetime/corruption primitive requiring exploitation-leverage review. It is not `CLASS_A` because arbitrary write, controlled replacement, or demonstrated privilege escalation is not established.
Demonstrated consequence: kernel crash / DoS via stack protector panic and bad pointer dereference.
Speculative consequence: confidentiality or integrity impact may be possible in worst case because kernel stack corruption can affect control data, but the supplied evidence does not establish a reliable exploit primitive.
ImportantCandidate=YES because concrete kernel stack corruption via a stale pointer is stronger than ordinary crash-only invalid dereference.
AutoDowngradeAllowed=NO because automatically closing this as ordinary Moderate would lose a real post-lifetime stack corruption primitive with unresolved exploitation leverage.
5. One-sentence report phrase
A stale stack-backed buffer in mwifiex synchronous command handling can remain attached to the current command after an interrupted wait, allowing a late firmware response to write into expired kernel stack memory and cause kernel stack corruption and DoS.
6. Manual review recommendation
MANUAL CHECK REQUIRED
Reason: this is a real post-lifetime kernel stack write with observed stack corruption, not merely a NULL dereference or resource leak.
7. Call-site confidence
Call-site confidence: medium
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: wifi: mwifiex: Detach sync cmd buffer on interrupted wait
Commit: 20ee9c03f261bf6ac59331e2ca7b46b23646412a
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=20ee9c03f261bf6ac59331e2ca7b46b23646412a
Commit description:
mwifiex synchronous commands keep the caller-provided data buffer in
cmd_node->data_buf. Several callers pass stack-allocated objects there.
If wait_event_interruptible_timeout() is interrupted, the caller can
return and release that stack object while the firmware command is still
the current command. A late firmware response then reaches the normal
response handler, which can copy data through cmd_node->data_buf into the
stale stack address.
This fixes a stack corruption observed during repeated association and
disassociation cycles. The panic trace showed the command wait being
interrupted immediately before a bad pointer dereference:
cmd_wait_q terminated: -512
Unable to handle kernel paging request at virtual address 002c583837384662
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted
...
Tainted: [M]=MACHINE_CHECK
The fault address decodes as little-endian ASCII:
0x002c583837384662 -> "bF878X,\0"
which is a fragment of the VERSION_EXT firmware string exposed as
debugfs "verext":
w8997o-V4, RF878X, FP92, 16.92.21.p153.7
The same runs also showed corrupted control data containing:
0x2400372e333531 -> "153.7\0$"
which is the tail of the same VERSION_EXT string. This points at a late
VERSION_EXT response writing through a stale stack-backed data_buf after
the interrupted wait returned.
After cancelling pending commands on an interrupted or timed-out wait,
detach the caller-owned data buffer from the still-current command. This
preserves the existing command cancellation behaviour while preventing a
late response from writing through a pointer whose lifetime ended with the
waiting caller.
Tested on an i.MX8MP board using an 88W8997.
Cc: [email protected]
Fixes: 3d026d0 ("mwifiex: cancel pending commands for signal")
Signed-off-by: Fabio Estevam <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Changed files:
drivers/net/wireless/marvell/mwifiex/sta_ioctl.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=20ee9c03f261bf6ac59331e2ca7b46b23646412a
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-80944 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80944
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:L/A:H
The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
The Best / paranoid CVSS score: 7
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).
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