CRITICAL: Kernel Panics/Instability by Broadcom Wi-Fi Driver Bug WLC_SCB_DEAUTHORIZE error -30

[Magnus2]

Subject: CRITICAL: Kernel Panics/Instability Caused by Broadcom Wi-Fi Driver Bug (WLC_SCB_DEAUTHORIZE error (-30)) - Requires Urgent Fix

Dear ASUS Support/Development Team,

I am writing to report a recurring and critical stability issue in my AiMesh network, which appears to be directly caused by a fundamental bug in the Broadcom Wi-Fi kernel driver, particularly affecting client memory management (SCB). This issue causes the entire network to suffer significant slowdowns and, eventually, instability, requiring a daily reboot.

1. Hardware and Firmware:

• Main Router: RT-BE92U

• AiMesh Node: RT-BE92U

• Firmware Version: [Latest 3.0.0.6] (The issue persists across multiple recent versions).

2. The Core Problem:

The issue manifests as a frequent, repeatable kernel error that occurs primarily when modern clients (especially Apple devices, which use aggressive power-save modes like APSD) attempt to disconnect or go into deep sleep due to inactivity.

The specific error is WLC_SCB_DEAUTHORIZE error (-30), which indicates a memory management failure in the Station Control Block (SCB) within the Broadcom kernel code.

3. Log Evidence from Router (Main Unit - [ROUTER_IP]) and AiMesh Node ([NODE_IP]):

The problem is triggered on both the main router and the AiMesh node, across 2.4 GHz, 5 GHz, and 6 GHz bands:

Date & Time	Location	Log Snippet	Interpretation
Nov 9 00:30:17	Main Router	kernel: WLC_SCB_DEAUTHORIZE error (-30)	The critical kernel error.
Nov 9 00:30:17	Main Router	wl1.3: Deauth_ind [CLIENT_MAC_A], reason: Disassociated due to inactivity (4)	The error is directly preceded by a client disconnecting due to inactivity, linking the bug to power-save management (APSD).
Nov 3 23:17:24	AiMesh Node	kernel: === MLO ERROR [wlc_ap_process_assocreq] Assoc processing failure... status 30 ===	Crucial finding: This error directly implicates the Multi-Link Operation (MLO) logic, which is part of the Wi-Fi 7 (802.11be) implementation in the Broadcom driver.
Nov 5 09:49:29	AiMesh Node	kernel: WLC_SCB_DEAUTHORIZE error (-30)	Shows the bug is widespread across the network.

4. Troubleshooting & Technical Findings:

Through extensive testing, we have determined:

1. Bug Scope: The bug affects all wireless interfaces (wl0, wl1, wl2) and occurs regardless of whether the network uses WPA2 or WPA3 security.

2. Client Trigger: The bug is most frequently triggered by modern clients that heavily rely on advanced power-save features (like Apple iPhones, Watches, and Apple TV 4K).

3. Root Cause Hypothesis: The bug lies in the Broadcom kernel code's handling of:

   • A) Multi-Link Operation (MLO) / Wi-Fi 7

   • B) WMM Automatic Power Save Delivery (APSD), or similar features that manage client state when an inactive device disconnects. The driver fails to correctly clear the Station Control Block (SCB) memory, leading to kernel instability.

5. Implemented Workaround:

Since full network stability cannot be maintained, the only viable workaround is to schedule frequent reboots to clear the corrupted kernel state before stability degrades entirely.

• Temporary Workaround: Daily/Near-daily scheduled reboots (e.g., Mon, Wed, Fri, Sat @ 02:30 AM).

6. Call to Action:

This is not a configuration issue; it is a deep-seated kernel bug in the Broadcom Wi-Fi driver code used by your high-end routers.

We request that ASUS/Broadcom prioritize and issue a firmware fix that addresses the core WLC_SCB_DEAUTHORIZE error (-30) bug, especially in relation to MLO/Wi-Fi 7 and power-save delivery logic.

Thank you for your urgent attention to this critical stability issue.

[Alex52]

I can confirm I  see this same error in my GT-BE98 Pro main logs.

System:

GT-BE98 Pro  with MLO GT-BE98 Pro and BE96U mesh nodes.

However, the error is not causing appreciable slowdown or a need to reboot my system.

[Magnus2]

Hi Alex, yeah, 95% of the occurances don't cause the Kernel panic or slowdowns but eventually mine crashes, can take a day, can take 2 weeks.

Update:

Test 1: Disabling Wi-Fi 7 Mode (MLO)

• Result: Reduced frequency of the error, but the bug persisted.

Test 2: Disabling WMM Automatic Power Save Delivery (APSD)

• Action Taken: WMM APSD was disabled on all bands (2.4, 5, and 6 GHz) on Nov 10th @ 12:48 PM CET.

• Result: Failed Overnight. The network ran stable for nearly 12 hours, which is a significant improvement over previous tests. However, the critical error finally recurred just after midnight:

  • Nov 11 00:30:33 on the AiMesh Node 

  • The trigger was a de-authentication from an Apple TV 4K 

Conclusion: Disabling APSD extended stability but did not eliminate the core memory/SCB bug. This strongly suggests the issue is a fundamental flaw in the Broadcom kernel code itself, likely relating to the 6 GHz band's interaction with the AiMesh architecture and/or power management.

[Alex52]

I disabled 5GHz Control Channel DFS and gained more performance. This might give your system some more stability in the meantime.

[jzchen]

Finally found a moderator id!  Please, please check on this thread @Aureliannn_ASUS