"Uncontiguous data cannot be linearized" error in nRF7002 Wi-Fi Connection

[funkySanrits]

I am encountering the error message "<err> net_pkt: Uncontiguous data cannot be linearized" when already connected with nRF7002-DK to a Wi-Fi network using the EAP-TLS authentication method over FreeRADIUS server. The error appears periodically after the successful handshake and connection processes. The `net ping 8.8.8.8.` further confirms that the connection is OK. However under the same conditions and configuration, this error message DOES NOT appear on the Zephyr master branch, commit [2879607](github.com/.../28796076d84056d085e5a4ebf213dafbfe56202a)

Setup Details
- Hardware: nRF7002-DK
- Firmware: NCS v2.8.0
- Development OS: Ubuntu 22.04 LTS
- Wi-Fi Setup: EAP-TLS authentication over FreeRADIUS
- Sample Used: `/samples/net/wifi`

Test case steps

1. Set up the Wi-Fi AP with WPA2-Enterprise and FreeRADIUS for EAP-TLS authentication.
2. Generated valid CA, certificates, and keys on the FreeRADIUS, then transferred them to the sample's /test_certs folder. Two sets of certificates were created since the sample requires them for both authentication phases. In this case, I've created the same certificates for both phases to simplify things. Therefore:

ca.pem = ca2.pem
client-key.pem = client-key2.pem
client.pem = client2.pem

3. Edited overlay-enterprise.conf :

CONFIG_NET_PKT_TX_COUNT=36
CONFIG_NET_PKT_RX_COUNT=36
CONFIG_NET_BUF_TX_COUNT=72
CONFIG_NET_BUF_RX_COUNT=36

CONFIG_MBEDTLS_ENABLE_HEAP=y
CONFIG_MBEDTLS_HEAP_SIZE=70000

CONFIG_WIFI_NM_WPA_SUPPLICANT_LOG_LEVEL_DBG=y
CONFIG_LOG_BUFFER_SIZE=16384

CONFIG_WIFI_NM_WPA_SUPPLICANT_CRYPTO_ENTERPRISE=y
CONFIG_WIFI_NM_WPA_SUPPLICANT_EAPOL=y
CONFIG_EAP_TLS=y


4. Built and flashed the `samples/net/wifi` sample from the NCS 2.8.0, configured with valid client certificates and keys.

west build -b nrf7002dk/nrf5340/cpuapp -- -DEXTRA_CONF_FILE=overlay-enterprise.conf
west flash

5. Entered `wifi connect` command (use your arguments):

wifi connect -s "MikroTikChateau-WLAN-2" -k 7 -a "user-tls" -K "sanri"


Logs
I have attached logs captured during the connection attempt with Minicom, showing the full error trace and related context. The logs are available in the attached ncs_2_8_0_wifi_shell_tls.txt file:
ncs_2_8_0_wifi_shell_tls.txt

[Håkon Alseth]

Hi,

 

Thank you so much for the detailed report and debug information. This is very helpful in terms of reproducing and git blame.

I am checking internally to see which fixes can specifically be targeted towards this stability issue, and I will get back to you within a few business days.

 

Kind regards,

Håkon