[CVE-2026-80522][IMPORTANT] crypto: tegra - fix rctx->cryptlen calculation in tegra_gcm_do_one_req() [ Upstream

[CVE-2026-80522][IMPORTANT] crypto: tegra - fix rctx->cryptlen calculation in tegra_gcm_do_one_req() [ Upstream

[AL-KERNEL]

CVE: CVE-2026-80522
Priority: IMPORTANT
AL-KERNEL base severity: IMPORTANT
KPANIC flag: YES
Patch: crypto: tegra - fix rctx->cryptlen calculation in tegra_gcm_do_one_req() [ Upstream
Commit: cd6991001bf0681ed0bcf21f9cc3d261d749b2bb
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cd6991001bf0681ed0bcf21f9cc3d261d749b2bb
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80522
Analysis date: Wed, 26 Aug 2026 12:28:59 -0400
ActionableScore: 7
ActionableScore lower bound: 6
Actionable bucket: Strong Important candidate / Actionable Moderate at minimum
Manual review required: YES

Summary:
A local attacker may trigger an out-of-bounds write in the Tegra crypto GCM decrypt path when authsize is not initialized correctly, causing kernel memory corruption and at least a crash, with possible privilege escalation requiring manual review.

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

The original Linux kernel CVE announcement for CVE-2026-80522 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80522

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: IMPORTANT
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-2026-80522	IMPORTANT	CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-787;CWE-682;CWE-131;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.8';DESCR 'A kernel out-of-bounds write may occur in the Tegra crypto GCM decrypt path because rctx cryptlen can be calculated with ctx authsize equal to zero when the caller did not set the GCM authentication size. This makes the decrypt path treat the authentication tag as payload and can write beyond the destination scatterlist buffer. For the CVSS the PR:L is used because reliable triggering requires local code execution through a crypto API user such as AF_ALG or another local consumer, but does not necessarily require full administrator privileges. The issue is not directly network reachable and depends on a system using the Tegra Security Engine driver with the affected GCM AEAD implementation. Impact is at least local denial of service via kernel memory corruption and in the worst case may allow confidentiality or integrity impact including privilege escalation, so it should be reviewed manually.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Strong Important candidate / Actionable Moderate at minimum (with actual score 7)	YES	DANGER SIMPLEFIX LINUS KPANIC  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS	YES	NO	checked

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

ActionableScore=7
ActionableScoreLower=6

## 1. ActionableScore

* Conservative score: 6
* Paranoid score: 7
* Final recommended bucket: **Strong Important candidate / Actionable Moderate at minimum**::

## 2. Signal breakdown

Triggered signals:

* Local unprivileged trigger: +1
  Likely reachable by a local user through the kernel crypto API, for example AF_ALG or another local AEAD consumer, if the Tegra GCM algorithm is registered and usable.

* Generic memory corruption, strong corruption primitive: +2
  The commit explicitly states that incorrect `rctx->cryptlen` can lead to a write beyond `rctx->dst_sg` buffer. This is an OOB write, not only a warning or NULL dereference.

* Privilege escalation plausible: +1 conservative, +2 paranoid
  Conservative score uses weak LPE concern because the patch shows kernel OOB write but does not demonstrate target selection, reclaim, or an exploit primitive. Paranoid score uses stronger LPE concern because attacker-influenced AEAD decrypt output written past a scatterlist destination buffer is a plausible kernel memory corruption path.

* Local unprivileged high-control kernel data-plane API: +1
  Crypto AEAD operations allow local callers to shape buffers, lengths, IV, ciphertext, authentication tag handling, and request layout at relatively high granularity.

* Reliable kernel crash / strong DoS: +1
  The commit explicitly says the bug may lead to a crash.

* Rare hardware / configuration dependency: -1
  The issue depends on the Tegra Security Engine driver and affected GCM AEAD implementation, so exposure is narrower than generic kernel crypto code.

Not counted:

* Remote reachable: +0
  No direct network packet path is shown.

* Availability impact realistic: +0 separately
  Crash impact is already counted as strong DoS, and there is no additional persistent availability effect shown.

## 3. Reachability analysis

A realistic trigger requires a system with the Tegra Security Engine crypto driver enabled and the affected GCM AEAD implementation available. The likely attacker model is local code execution using AF_ALG or another local crypto API consumer that can submit a GCM decrypt request without the expected authsize setup path. This does not appear to require full administrator privileges in principle, although actual exposure depends on product configuration and whether the hardware crypto algorithm is exposed to unprivileged users.

Namespaces do not obviously create a separate remote boundary here. Container impact depends on whether the container can access AF_ALG or another crypto consumer path on the host kernel. The issue is not directly network reachable.

Call-site confidence: medium. The affected function and failure mode are visible, but the full set of user reachable call paths is not included in the supplied patch.

## 4. Severity interpretation

This is stronger than an ordinary Moderate because the patch describes an explicit kernel out-of-bounds write beyond a destination scatterlist buffer. The realistic demonstrated impact is local kernel crash or memory corruption on Tegra systems. A practical privilege escalation path is not demonstrated, but the bug class and affected buffer semantics justify manual review and paranoid Important-candidate handling.

Conservatively, this is an Actionable Moderate at minimum. Paranoid triage should treat it as a Strong Important candidate because local attacker-controlled crypto input can plausibly influence an OOB write in kernel memory.

## 5. One-sentence report phrase

A local attacker may trigger an out-of-bounds write in the Tegra crypto GCM decrypt path when authsize is not initialized correctly, causing kernel memory corruption and at least a crash, with possible privilege escalation requiring manual review.

## 6. Manual review recommendation

MANUAL CHECK REQUIRED

Reason: the patch explicitly fixes an OOB write beyond `rctx->dst_sg`, which is concrete kernel memory corruption. Even though exploitation is hardware-dependent and no full LPE primitive is demonstrated, this should not be auto-closed.

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

Patch: crypto: tegra - fix rctx->cryptlen calculation in tegra_gcm_do_one_req() [ Upstream
Commit: cd6991001bf0681ed0bcf21f9cc3d261d749b2bb
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cd6991001bf0681ed0bcf21f9cc3d261d749b2bb

Changed files:
  drivers/crypto/tegra/tegra-se-aes.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=cd6991001bf0681ed0bcf21f9cc3d261d749b2bb

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

The original Linux kernel CVE announcement for CVE-2026-80522 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80522

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:L/PR:L/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7.8

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: 6
  Paranoid ActionableScore: 7

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: IMPORTANT
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): IMPORTANT

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).