Stack overflow after reboot – Wi-Fi provisioning over BLE (nRF7002 DK)

[skim]

Using the Wi-Fi Fundamentals – Lesson 2, Exercise 3 (Provisioning over Bluetooth LE) sample from Nordic Semiconductor DevAcademy (GitHub solution l2e3_sol, main branch), the application builds and runs correctly on first boot: BLE provisioning succeeds and Wi-Fi connects as expected. However, after rebooting the device, a stack overflow occurs during startup.

This is reproducible on nRF Connect SDK v3.1.0 and v3.2.1 using board target nrf7002dk/nrf5340/cpuapp/ns, with no significant modifications to the sample. Logs showing successful first-boot connection and the post-reboot stack overflow are attached.

*** Booting nRF Connect SDK v3.2.1-d8887f6f32df ***
*** Using Zephyr OS v4.2.99-ec78104f1569 ***
[00:00:01.706,176] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:01.706,207] <inf> bt_hci_core: HW Variant: nRF53x (0x0003)
[00:00:01.706,237] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 252.16862 Build 1121034987
[00:00:01.708,801] <inf> bt_hci_core: HCI transport: IPC
[00:00:01.708,984] <inf> bt_hci_core: Identity: CF:9C:C1:D3:44:74 (random)
[00:00:01.709,014] <inf> bt_hci_core: HCI: version 6.1 (0x0f) revision 0x2069, manufacturer 0x0059
[00:00:01.709,045] <inf> bt_hci_core: LMP: version 6.1 (0x0f) subver 0x2069
[00:00:01.709,075] <inf> Lesson2_Exercise3: Bluetooth initialized.

[00:00:01.709,075] <inf> Lesson2_Exercise3: Wi-Fi provisioning service starts successfully.

[00:00:01.711,639] <inf> Lesson2_Exercise3: BT Advertising successfully started.

[00:00:12.163,085] <inf> Lesson2_Exercise3: BT Connected: 7C:13:74:15:81:40 (random)
[00:00:13.181,274] <inf> Lesson2_Exercise3: BT Disconnected: 7C:13:74:15:81:40 (random) (reason 0x13).

[00:00:13.181,457] <inf> Lesson2_Exercise3: Cannot update advertisement data, err = -11

[00:00:16.911,499] <inf> Lesson2_Exercise3: BT Connected: 6F:E8:49:A3:F4:CE (random)
[00:00:19.841,033] <inf> Lesson2_Exercise3: BT pairing completed: 6F:E8:49:A3:F4:CE (random), bonded: 0

[00:00:19.841,217] <inf> Lesson2_Exercise3: BT Security changed: 6F:E8:49:A3:F4:CE (random) level 2.

[00:00:20.516,143] <inf> wifi_prov: Wi-Fi Provisioning service - control point: indications enabled
[00:00:20.786,163] <inf> wifi_prov: Wi-Fi Provisioning service - data out: notifications enabled
[00:00:21.146,636] <inf> wifi_prov: Start parsing...
[00:00:21.146,667] <inf> wifi_prov: GET_STATUS received...
[00:00:22.316,467] <inf> wifi_prov: Start parsing...
[00:00:22.316,497] <inf> wifi_prov: Start_Scan received...
[00:00:28.346,496] <inf> wifi_prov: Start parsing...
[00:00:28.346,527] <inf> wifi_prov: Stop_Scan received...
[00:01:56.366,943] <inf> wifi_prov: Start parsing...
[00:01:56.366,973] <inf> wifi_prov: Set_config received...
[00:02:09.303,314] <inf> Lesson2_Exercise3: Network connected
*** Booting nRF Connect SDK v3.2.1-d8887f6f32df ***
*** Using Zephyr OS v4.2.99-ec78104f1569 ***
[00:00:00.591,796] <err> os: ***** USAGE FAULT *****
[00:00:00.591,796] <err> os:   Stack overflow (context area not valid)
[00:00:00.591,827] <err> os: r0/a1:  0x20019800  r1/a2:  0x2001e266  r2/a3:  0x0000000f
[00:00:00.591,827] <err> os: r3/a4:  0x2001c594 r12/ip:  0x00000008 r14/lr:  0x00071643
[00:00:00.591,857] <err> os:  xpsr:  0x41000200
[00:00:00.591,857] <err> os: Faulting instruction address (r15/pc): 0x0006eac6
[00:00:00.591,888] <err> os: >>> ZEPHYR FATAL ERROR 2: Stack overflow on CPU 0
[00:00:00.591,918] <err> os: Current thread: 0x2001b0b8 (unknown)
[00:00:00.658,233] <err> os: Halting system

[Susheel Nuguru]

Seems like the main stack usage has gone up here, can you please try increasing the main stack size and also setting stack sentinels to catch stack overflow errors

CONFIG_MAIN_STACK_SIZE=8192
CONFIG_STACK_SENTINEL=y

[skim]

Thanks for the suggestion. I tried the recommended configuration changes and rebuilt the application, but the issue still persists. The behavior is unchanged: the sample works on first boot, but after reboot it still hits a stack overflow. The logs are the same as previously shared.

[Susheel Nuguru]

Just tested this on nRF Connect SDKv3.2.0 and I do not see any faults or overflows even after many resets .. provisioned the device already as per the exercise.

Build configuration is same as yours

[skim]

Hello,

Thanks for testing this.

One thing I noticed while reproducing the issue: when provisioning with the Android nRF WiFi Provisioner app, if “Persist Credentials” is set to true, the device attempts to automatically reconnect to Wi-Fi after reboot, and I observe a stack overflow during startup.

If “Persist Credentials” is set to false, the device does not auto-reconnect after reboot, and I do not see the stack overflow.

In the logs you shared, after reboot the application appears to stop at Bluetooth advertising and does not attempt Wi-Fi reconnection. Could you confirm whether Wi-Fi credentials were persisted in your test (i.e., whether “Persist Credentials” was enabled during provisioning)?

Thanks for checking.

[Susheel Nuguru]

Hi Kim, 

Are you erasing the credentials when rebooting? If not then the device tries to reconnect to the already existing credentials.