From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-80754][MODERATE 7.0] Input: synaptics-rmi4 - fix F55 transmitter electrode count typo Date: Thu, 03 Sep 2026 05:44:49 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-80754 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 6 X-AL-KERNEL-ActionableScore-Lower: 3 X-AL-KERNEL-Commit: 6484e00d6778fdf2209cd75940bc3902b276457f List-Id: CVE: CVE-2026-80754 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: Input: synaptics-rmi4 - fix F55 transmitter electrode count typo Commit: 6484e00d6778fdf2209cd75940bc3902b276457f Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6484e00d6778fdf2209cd75940bc3902b276457f Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80754 Analysis date: Thu, 03 Sep 2026 05:44:49 -0400 ActionableScore: 6 ActionableScore lower bound: 3 Actionable bucket: Actionable Moderate at minimum Manual review required: YES Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80754 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80754 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-2026-80754 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-80754 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-131;*CWE-787;CWE-125;Other CVSS 'AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7';DESCR 'An out of bounds buffer access risk exists in the Synaptics RMI4 F55 and F54 path because the TX electrode count can be incorrectly copied from the RX electrode count. The wrong TX value is propagated into driver data and can make F54 calculate an incorrect diagnostic report size on devices with more RX than TX electrodes. The most direct impact is a local or physical denial of service through a kernel crash on affected hardware. For the CVSS the PR:L is used for the paranoid score because a local user or service may be able to trigger F54 diagnostics or interact with an already present RMI4 device, while direct remote network triggering is not supported. In the worst still defensible case, the out of bounds access may represent kernel memory corruption and could allow confidentiality or integrity impact in addition to availability impact.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5) YES WRITE OOB SIMPLEFIX HARDWARE LINUS KPANIC DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=6 ActionableScoreLower=3 1. ActionableScore * Conservative score: 3 * Paranoid score: 6 * Final recommended bucket: **Actionable Moderate at minimum**:: 2. Signal breakdown * Firmware-mediated external influence: +1. The incorrect values originate from RMI4 F55 sensor detection and device-reported electrode counts. * Local unprivileged trigger, paranoid only: +1. A local user or local service may be able to reach F54 diagnostics or input-device diagnostic paths on an already present device, but this needs confirmation. * Memory corruption, weak or indirect corruption candidate: +1. The commit explicitly mentions potential out-of-bounds buffer accesses, but the patch does not show a concrete attacker-controlled overwrite, reclaim, type confusion, or arbitrary write primitive. * Memory layout invariant restoration: +1. The patch restores consistency between RX and TX electrode counts used later for F54 diagnostic report size calculation. * Reliable kernel crash / strong DoS: +1. Incorrect report sizing with OOB access can plausibly crash the kernel on affected hardware. * Confidentiality impact plausible, paranoid only: +1. OOB access could theoretically include read-side exposure, but no direct disclosure path is shown. * Integrity impact plausible, paranoid only: +1. If the OOB access includes writes, kernel memory corruption is possible, but this is not demonstrated by the patch. * Rare hardware / difficult-to-reach configuration: -1. The issue depends on Synaptics RMI4 hardware and on devices where RX electrode count is greater than TX electrode count. * Conservative limiting factor: no demonstrated strong primitive. The patch and message do not prove attacker-controlled payload, controlled target selection, UAF reclaim, callback control, or arbitrary write. 3. Reachability analysis The most direct trigger depends on affected Synaptics RMI4 hardware and F54 diagnostic report paths consuming the incorrect TX count. This is not network reachable. It is not a broad default kernel path. The realistic attacker model is local interaction with an existing input device or diagnostic interface, or firmware/device-provided parameters during detection. Namespace effects are likely limited because input diagnostic interfaces are usually host-device specific and may be permission restricted. Call-site confidence: medium, because the patch explains the F55 to F54 propagation and report-size consequence, but the full F54 call sites and userspace permissions are not included. 4. Severity interpretation This is stronger than an ordinary typo because the wrong count is propagated into report-size logic and the commit explicitly states potential out-of-bounds buffer accesses. It is still not a clear Important-class issue on conservative evidence because there is no demonstrated write primitive, attacker-controlled memory layout, UAF, type confusion, or privilege escalation chain. The paranoid interpretation is Actionable Moderate because kernel OOB access in an input driver can plausibly become more than DoS and should not be auto-closed without checking the F54 allocation and diagnostic paths. 5. One-sentence report phrase A wrong TX electrode count in Synaptics RMI4 F55 can be propagated into F54 diagnostic report sizing, leading to potential out-of-bounds buffer access and likely local or device-mediated DoS, with paranoid concern for kernel memory corruption on affected hardware. 6. Manual review recommendation MANUAL CHECK REQUIRED. YES REQUIRES MANUAL CHECK because the patch explicitly mentions potential out-of-bounds buffer accesses and the F54 diagnostic call paths must be reviewed to determine whether the primitive is read-only, write-capable, or reachable by unprivileged local users. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: Input: synaptics-rmi4 - fix F55 transmitter electrode count typo Commit: 6484e00d6778fdf2209cd75940bc3902b276457f Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6484e00d6778fdf2209cd75940bc3902b276457f Commit description: During F55 sensor detection, the transmitter (TX) electrode count was incorrectly assigned the value of the receiver (RX) electrode count due to copy-paste typos. This incorrect value was then propagated to the driver data and used by F54 to determine the diagnostics report size. On devices with more RX than TX electrodes, this inflated the perceived TX count, leading to incorrect report size calculations and potential out-of-bounds buffer accesses. Fix the typos by correctly assigning the TX electrode counts. Fixes: 6adba43 ("Input: synaptics-rmi4 - add support for F55 sensor tuning") Fixes: c762cc6 ("Input: synaptics-rmi4 - propagate correct number of rx and tx electrodes to F54") Reported-by: sashiko-bot@kernel.org Cc: stable@vger.kernel.org Assisted-by: Antigravity:gemini-3.5-flash Link: https://patch.msgid.link/20260626051802.4033172-1-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman Changed files: drivers/input/rmi4/rmi_f55.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=6484e00d6778fdf2209cd75940bc3902b276457f ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-80754 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-80754 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:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/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: 6 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).