[CVE-2026-64315][MODERATE REGULAR] crypto: caam - use print_hex_dump_devel to guard key hex dumps again

[AL-KERNEL <alkernel@kernelcve.org>]

CVE: CVE-2026-64315
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: crypto: caam - use print_hex_dump_devel to guard key hex dumps again
Commit: 1ec775f6a124cce6278ae58b7d1c78a3bc6eef23
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1ec775f6a124cce6278ae58b7d1c78a3bc6eef23
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64315
Analysis date: Sat, 25 Jul 2026 15:30:03 -0400
ActionableScore: 3
ActionableScore lower bound: 1
Actionable bucket: Borderline Moderate / manual review recommended due cryptographic key exposure
Manual review required: YES

Summary:
CAAM/DPAA2 crypto setkey paths could leak full key material through dynamic debug hex dumps when CONFIG_DYNAMIC_DEBUG is enabled and the resulting kernel debug output is accessible.

======================================================================
ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-64315 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64315

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 REGULAR
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-2026-64315	MODERATE	CHECK WITH IMPACT FROM ORIG NN LOW	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:N/A:N';CWE-532;*CWE-200;CWE-312;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N';BEST CVSS score: '4.7';DESCR 'CAAM/DPAA2 crypto setkey paths could expose sensitive key material because print_hex_dump_debug may emit key buffers at runtime when CONFIG_DYNAMIC_DEBUG is enabled for these callsites. This can leak full AEAD or skcipher keys into kernel debug output or logs if debug printing is enabled and the logs are accessible. For the CVSS the PR:L is used for the paranoid score because a reduced-capability service account or local user may be able to read kernel logs in an environment where dynamic debug was already enabled by an administrator. Direct enabling of dynamic debug normally requires administrative privileges, so the base score uses PR:H. The issue is local and configuration dependent, not directly network reachable. Impact is confidentiality loss of cryptographic keys, with no evidence of memory corruption, privilege escalation, or availability impact.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline Moderate / manual review recommended due cryptographic key exposure (with actual score 2)	YES	SIMPLEFIX LEAK LINUS MEMORY  DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	YES	NO	checked

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

ActionableScore=3
ActionableScoreLower=1

## 1. ActionableScore

* Conservative score: 1
* Paranoid score: 3
* Final recommended bucket: **Borderline Moderate / manual review recommended due cryptographic key exposure**::

## 2. Signal breakdown

Conservative signals:

* Sensitive file / credential / secret exposure primitive: +2
  The patch prevents full AEAD or skcipher key buffers from being dumped through CAAM setkey paths.
* Confidentiality impact plausible: +1
  If emitted to kernel debug output and readable by an attacker, the leaked material is cryptographic key material.
* Requires admin/root/CAP level control in typical deployments: -2
  Enabling the relevant dynamic debug callsites and accessing kernel logs is normally administrator controlled.
* Non-default runtime exposure condition: -1
  Practical leakage requires CONFIG_DYNAMIC_DEBUG and runtime debug output enabled for these callsites.

Paranoid additional interpretation:

* Local reduced-privilege exposure concern: +1
  In some deployments dynamic debug may already be enabled by an administrator, and a reduced-privilege service account or local user may have access to collected kernel logs or debug output.

No memory corruption, UAF, OOB write, privilege escalation, or DoS signal is supported by this patch.

## 3. Reachability analysis

The affected path is local and configuration dependent. It is reached when CAAM/DPAA2 crypto algorithms execute setkey operations and the debug dump callsites are active. In typical systems, enabling dynamic debug and reading kernel logs requires administrative privileges, so conservative reachability is PR:H-like. A more paranoid deployment model is possible if debug output was pre-enabled and logs are exposed to a less privileged local user or service account. This is not network reachable by itself, although leaked keys may belong to network-facing crypto users.

Call-site confidence: high. The patch directly shows the affected setkey paths and the sensitive buffers being passed to hex dump helpers.

## 4. Severity interpretation

This behaves like an information disclosure issue, not memory corruption. The realistic impact is confidentiality loss of cryptographic keys under specific debug and log-access conditions. It is not an Important-class kernel memory corruption issue, but it should not be blindly auto-closed if the evaluated product commonly enables dynamic debug or exposes kernel logs to non-root users.

## 5. One-sentence report phrase

CAAM/DPAA2 crypto setkey paths could leak full key material through dynamic debug hex dumps when CONFIG_DYNAMIC_DEBUG is enabled and the resulting kernel debug output is accessible.

## 6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Manual review is recommended because the issue can expose complete cryptographic keys, but the practical risk depends heavily on CONFIG_DYNAMIC_DEBUG, runtime debug settings, CAAM hardware usage, and kernel log access policy.

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

Patch: crypto: caam - use print_hex_dump_devel to guard key hex dumps again
Commit: 1ec775f6a124cce6278ae58b7d1c78a3bc6eef23
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1ec775f6a124cce6278ae58b7d1c78a3bc6eef23

Commit description:

Use print_hex_dump_devel() for dumping sensitive key material in
*_setkey() to avoid leaking secrets at runtime when CONFIG_DYNAMIC_DEBUG
is enabled.

Fixes: 8d818c1 ("crypto: caam/qi2 - add DPAA2-CAAM driver")
Fixes: 226853a ("crypto: caam/qi2 - add skcipher algorithms")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changed files:
  drivers/crypto/caam/caamalg_qi2.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=1ec775f6a124cce6278ae58b7d1c78a3bc6eef23

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

The original Linux kernel CVE announcement for CVE-2026-64315 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64315

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:H/I:N/A:N
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
  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: 3

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: NO
Published priority for this report (same as in Subject): MODERATE REGULAR

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).