[CVE-2024-42301][MODERATE 7.0] dev/parport: fix the array out-of-bounds risk

[CVE-2024-42301][MODERATE 7.0] dev/parport: fix the array out-of-bounds risk

[AL-KERNEL]

CVE: CVE-2024-42301
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: dev/parport: fix the array out-of-bounds risk
Commit: 7f4da759092a1a6ce35fb085182d02de8cc4cc84
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7f4da759092a1a6ce35fb085182d02de8cc4cc84
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2024-42301
Analysis date: Mon, 12 Oct 2026 20:17:30 -0400
ActionableScore: 5
ActionableScore lower bound: 3
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-2024-42301 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2024-42301

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-2024-42301	MODERATE	https://www.kernelcve.org/list/?q=CVE-2024-42301 CHECK WITH IMPACT FROM ORIG NN IMPORTANT | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=2 LEGACY=MODERATE_KPANIC RESULT=SAME (legacy and Aegis reconciliation agree; 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:H/I:H/A:H';CWE-121;*CWE-787;CWE-120;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'The parport procfs handlers used unbounded sprintf operations to place device attributes and hardware address values into fixed size kernel stack buffers. Reading an affected procfs entry with sufficiently long formatted data can overwrite the end of the buffer. The observed failure reached the stack protector in do_hardware_base_addr and caused a kernel panic. For the CVSS the PR:L value assumes that an unprivileged local user can read the exposed parport procfs files without permission to reconfigure the device. The issue is not directly network reachable and normally requires a configured parport device with values or identification strings large enough to reach the overflow. Impact is at least a local denial of service through kernel stack corruption. In the worst case the out of bounds write may affect confidentiality and integrity or support local privilege escalation, although stack protection and limited control over the formatted data make reliable exploitation difficult.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 4)	MAYBE	WRITE OOB DANGER HARDWARE LINUS KPANIC  KPANIC DECREASED_TO_MODERATE70_BASED_ON_ACTIONABLESCORELOWERTHAN5	-	-	checked

======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=5
ActionableScoreLower=3
PrimitiveClass=CLASS_B
RealUAF=NO
HostAdminRequired=NO
NamespaceScopedPrivilege=NO
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
RequiresHostUID0=NO
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw conservative score: 3
* Conservative score: 3. No floor or cap applied.
* Raw paranoid score: 4
* Paranoid score: 5. The manual-review safety floor raises 4 to 5 because the stronger interpretation establishes an attacker-influenced kernel stack overwrite whose exploitation leverage remains unresolved.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

NEW52 B5-R does not apply. This is a stack overwrite without retry-accumulated indexing.

2. Signal breakdown

Conservative signals:

* +1 Constrained kernel buffer overwrite. Unbounded `sprintf()` performs confirmed writes beyond fixed stack buffers, but the demonstrated `base` values offer limited payload and target control.
* +1 Reliable kernel crash. The supplied trace confirms stack-canary corruption followed by kernel panic.
* +1 Local unprivileged trigger. The vulnerable procfs handlers are read handlers, and writing is explicitly rejected. Reading these parport status entries normally does not require host-administrator powers.
* Total: 3.

Paranoid signals:

* +2 Strong corruption primitive, replacing the conservative +1. The `do_autoprobe()` paths format variable-length device identification strings into a fixed stack buffer, providing a defensible attacker-influenced length and content interpretation when peripheral data can shape those strings.
* +1 Reliable kernel crash.
* +1 Local unprivileged trigger.
* Total: 4 before the safety floor.
* Applied paranoid floor: 4 -> 5.

Important non-awarded signals:

* No UAF, stale object, repeated release, or refcount mutation exists.
* Arbitrary target selection and arbitrary kernel write are not demonstrated.
* Controlled reclaim, callback control, credential corruption, and completed LPE are not demonstrated.
* No confidentiality or integrity point is awarded merely because stack corruption might theoretically support LPE.
* No extra Availability point is awarded because it would double-count the same panic.
* Remote reachability is not established.
* No race or retry-accumulation point applies.
* No authorization bypass, B3-PENDING, B4-PENDING, or B5-R profile applies.
* No hardware penalty is applied because the demonstrated crash came from a local read on an already configured system. Attacker-controlled peripheral descriptors remain relevant only to the paranoid interpretation.

3. Reachability analysis

An ordinary local process can trigger the demonstrated path by reading an affected parport procfs entry after a parport device has been registered. Numeric UID 0 and effective host-administrator capabilities are not required for the read operation under normal parport procfs permissions.

The system must already expose a parport instance. Device registration or physical provisioning can require prior administrator or platform setup, but that is separate from the subsequent vulnerable read. Namespace-scoped privilege is not relevant because this is a host procfs and device interface, not a namespace-created control path.

The demonstrated `do_hardware_base_addr()` panic does not require a race. Exploitation beyond panic depends on buffer contents, stack layout, stack-canary defenses, architecture, and whether device-derived autoprobe strings provide useful control. There is no direct network trigger.

4. Primitive and severity interpretation

The exact demonstrated primitive is an out-of-bounds write past a fixed-size kernel stack buffer caused by unbounded formatted output. This is real kernel memory corruption, not an OOB read or hypothetical bounds issue.

The conservative interpretation treats it as a constrained overwrite because the observed `do_hardware_base_addr()` payload consists of formatted kernel-held address values and the destination is a fixed local stack buffer. The demonstrated consequence is stack-canary detection and kernel panic.

The paranoid interpretation considers the separate `do_autoprobe()` writes, where variable-length device identification strings are concatenated into a fixed stack buffer. Those strings can plausibly be influenced by peripheral-provided identification data, making the overwrite stronger than the observed fixed numeric write. However, no chosen adjacent victim, arbitrary destination, reliable control-flow hijack, or privilege escalation is established.

This is CLASS_B rather than CLASS_A because a concrete overwrite exists but strong attacker-directed exploitation control is not independently proven. ImportantCandidate is YES because a real kernel stack overwrite with potentially influenced contents should not be automatically reduced to crash-only severity without examining input provenance and stack layout.

AutoDowngradeAllowed is NO because meaningful corruption leverage remains unresolved. Manual review is also required because the sequential `snprintf(buffer + len, sizeof(buffer) - len, ...)` conversion may itself be unsafe if `snprintf()` truncates and returns the larger would-have-written length, allowing `len` to exceed the buffer and the next remaining-size calculation to underflow.

5. One-sentence report phrase

Unbounded parport procfs formatting can overwrite a kernel stack buffer and cause a confirmed panic, while variable-length device identification strings leave potentially stronger corruption and local privilege-escalation leverage requiring manual review.

6. Manual review recommendation

MANUAL CHECK REQUIRED

Review the provenance and maximum lengths of all autoprobe strings, actual procfs permissions, affected stack layouts, and the correctness of the new cumulative `snprintf()` length handling.

7. Call-site confidence

Call-site confidence: medium

======================================================================
UPSTREAM PATCH SUMMARY
======================================================================

Patch: dev/parport: fix the array out-of-bounds risk
Commit: 7f4da759092a1a6ce35fb085182d02de8cc4cc84
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7f4da759092a1a6ce35fb085182d02de8cc4cc84

Commit description:

Fixed array out-of-bounds issues caused by sprintf
by replacing it with snprintf for safer data copying,
ensuring the destination buffer is not overflowed.

Below is the stack trace I encountered during the actual issue:

[ 66.575408s] [pid:5118,cpu4,QThread,4]Kernel panic - not syncing: stack-protector:
Kernel stack is corrupted in: do_hardware_base_addr+0xcc/0xd0 [parport]
[ 66.575408s] [pid:5118,cpu4,QThread,5]CPU: 4 PID: 5118 Comm:
QThread Tainted: G S W O 5.10.97-arm64-desktop #7100.57021.2
[ 66.575439s] [pid:5118,cpu4,QThread,6]TGID: 5087 Comm: EFileApp
[ 66.575439s] [pid:5118,cpu4,QThread,7]Hardware name: HUAWEI HUAWEI QingYun
PGUX-W515x-B081/SP1PANGUXM, BIOS 1.00.07 04/29/2024
[ 66.575439s] [pid:5118,cpu4,QThread,8]Call trace:
[ 66.575469s] [pid:5118,cpu4,QThread,9] dump_backtrace+0x0/0x1c0
[ 66.575469s] [pid:5118,cpu4,QThread,0] show_stack+0x14/0x20
[ 66.575469s] [pid:5118,cpu4,QThread,1] dump_stack+0xd4/0x10c
[ 66.575500s] [pid:5118,cpu4,QThread,2] panic+0x1d8/0x3bc
[ 66.575500s] [pid:5118,cpu4,QThread,3] __stack_chk_fail+0x2c/0x38
[ 66.575500s] [pid:5118,cpu4,QThread,4] do_hardware_base_addr+0xcc/0xd0 [parport]

Signed-off-by: tuhaowen <tuhaowen@uniontech.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20240708080430.8221-1-tuhaowen@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/parport/procfs.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=7f4da759092a1a6ce35fb085182d02de8cc4cc84

======================================================================
DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2024-42301 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2024-42301

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: 3
  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 alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).