* [CVE-2026-80949][LOW] wifi: brcmfmac: Fix memory leak in brcmf_sdio_read_control()
@ 2026-09-11 21:52 21% AL-KERNEL
0 siblings, 0 replies; 1+ results
From: AL-KERNEL @ 2026-09-11 21:52 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-80949
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: wifi: brcmfmac: Fix memory leak in brcmf_sdio_read_control()
Commit: fdb880a7d575efe8b5c7b5b819b96d9251a3937f
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fdb880a7d575efe8b5c7b5b819b96d9251a3937f
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80949
Analysis date: Fri, 11 Sep 2026 17:52:45 -0400
ActionableScore: 2
ActionableScore lower bound: 1
Actionable bucket: Ordinary Moderate
Manual review required: NO
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-80949 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80949
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: LOW
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-2026-80949 LOW https://www.kernelcve.org/list/?q=CVE-2026-80949 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:N/I:N/A:H';*CWE-401;*CWE-772;**CWE-400;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L';BEST CVSS score: '4.7';DESCR 'brcmf_sdio_read_control() can leak a dynamically allocated control frame buffer on some error paths in the brcmfmac SDIO Wi-Fi driver. The issue is a resource leak rather than a memory corruption primitive because the patch only fixes missing vfree handling and does not indicate UAF, OOB access, or arbitrary write. For the CVSS the PR:L is used for the paranoid case because reliable triggering is expected to require a local user or process able to influence Wi-Fi driver activity rather than only passive network reachability. The issue is not directly network reachable from normal IP traffic and would usually depend on local Wi-Fi management activity, firmware behavior, or a faulty device. Impact is denial of service via gradual memory exhaustion under repeated failures.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 2) YES REMOTE LEAK ERRORPATH UAF NETWORK LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN4 DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3 NO NO checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=2
ActionableScoreLower=1
PrimitiveClass=NONE
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=NO
ImportantCandidate=NO
ManualReview=NO
AutoDowngradeAllowed=YES
1. ActionableScore
* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 2
* Paranoid score: 2
* Final recommended bucket: **Ordinary Moderate**::
No floor or cap changed the score.
2. Signal breakdown
* +1 conservative. Concrete persistent kernel resource leak. The patch directly shows that a dynamically allocated control frame buffer may be lost on some error paths and fixes this by adding common `vfree(buf)` handling.
* +1 paranoid. Firmware or device mediated influence is plausible because this is an SDIO Wi-Fi control-frame receive path, but this is not direct network reachability from normal IP traffic.
Important non-awarded signals:
* RealUAF not awarded. The patch fixes a missing free, not use after free.
* CLASS_A or CLASS_B corruption not awarded. No OOB access, arbitrary write, stale active object use, double release, or refcount mutation is established.
* Reliable kernel crash not awarded. The demonstrated issue is a leak, not an immediate panic or fatal fault.
* Extra resource-exhaustion escalation not awarded conservatively. Sustained repeated failures could consume memory, but host-wide exhaustion is not shown as immediate or reliably reachable.
* C/I impact not awarded. No disclosure path or unauthorized modification primitive is established.
* Remote reachability not awarded. Device or firmware mediation is material, and normal network packets are not shown to directly reach the vulnerable operation.
3. Reachability analysis
The likely trigger is activity in the brcmfmac SDIO Wi-Fi control path combined with error paths in `brcmf_sdio_read_control()`. The supplied evidence does not prove that a normal remote Wi-Fi peer can directly and reliably trigger the leak through ordinary traffic. It also does not prove that host-admin-equivalent privileges are required. Therefore HostAdminRequired is UNKNOWN.
No namespace-scoped privilege path is involved or established. Prior setup requires affected Broadcom SDIO Wi-Fi hardware and the brcmfmac driver. Special hardware is relevant, but it is ordinary device-specific driver exposure rather than a rare physical-only attack requirement. No race or narrow timing requirement is established.
4. Primitive and severity interpretation
The exact primitive is a memory/resource leak of a dynamically allocated control frame buffer. This is not active structured stale-object use and not fixed stale storage UAF. There is no concrete repeated release/refcount operation. There is no evidence that the first lifetime operation frees an object and a second operation mutates the same dangling reference.
PrimitiveClass is NONE because the patch establishes resource leakage, not kernel memory corruption, authorization bypass, COW violation, or semantic security-boundary primitive. The demonstrated consequence is gradual memory consumption. The speculative consequence is denial of service via memory exhaustion if the error path can be repeated enough. ImportantCandidate is NO because no meaningful exploitation leverage beyond resource exhaustion is established. AutoDowngradeAllowed is YES because this is a low-end resource leak with no unresolved corruption or boundary primitive.
5. One-sentence report phrase
A missing `vfree()` in `brcmf_sdio_read_control()` can leak SDIO Wi-Fi control-frame buffers on error paths, potentially causing gradual memory exhaustion but not establishing memory corruption or privilege escalation.
6. Manual review recommendation
NO MANUAL CHECK NEEDED
Reason: this is a concrete but low-end resource leak with no UAF, no repeated lifetime mutation, no direct remote trigger, and no C/I/security-boundary primitive.
7. Call-site confidence
Call-site confidence: medium
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: wifi: brcmfmac: Fix memory leak in brcmf_sdio_read_control()
Commit: fdb880a7d575efe8b5c7b5b819b96d9251a3937f
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fdb880a7d575efe8b5c7b5b819b96d9251a3937f
Commit description:
The memory allocated for buf is not freed in some of the error paths in
brcmf_sdio_read_control(). Fix that by adding vfree() calls.
Cc: [email protected]
Fixes: dd43a01 ("brcmfmac: use dynamically allocated control frame buffer")
Signed-off-by: Abdun Nihaal <[email protected]>
[arend: rework as suggested by Johannes]
Signed-off-by: Arend van Spriel <[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/broadcom/brcm80211/brcmfmac/sdio.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=fdb880a7d575efe8b5c7b5b819b96d9251a3937f
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-80949 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80949
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: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:H
The Best / paranoid CVSS score: 4.7
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: 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: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW
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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