Bluetooth: tests: edtt: fix buffer overflow error

HCI/GEV/BV-01-C tries to send 255 bytes over HCI, as part of sending
an unknown/unsupported command, but the default buffer size
is 65, which results in a buffer overflow and undefined behaviour.
Instead of crashing hard we now check the buffer length.
In order for EDTT tests to pass we set the buffer size to 255

Signed-off-by: Andries Kruithof <[email protected]>

Author: Andries Kruithof

subsys/bluetooth/host/hci_raw.c

@@ -302,6 +302,10 @@ int bt_send(struct net_buf *buf)
 {
 	BT_DBG("buf %p len %u", buf, buf->len);
 
+	if (buf->len == 0) {
+		return BT_HCI_ERR_INVALID_PARAM;
+	}
+
 	bt_monitor_send(bt_monitor_opcode(buf), buf->data, buf->len);
 
 	if (IS_ENABLED(CONFIG_BT_HCI_RAW_CMD_EXT) &&

tests/bluetooth/bsim_bt/edtt_ble_test_app/hci_test_app/prj_dut.conf

@@ -10,8 +10,10 @@ CONFIG_BT_DEBUG_LOG=y
 CONFIG_BT_ECC=y
 CONFIG_BT_TINYCRYPT_ECC=y
 
+# BUF_CMD_TX_SIZE must be 255 because of HCI/GEV/BV-01-C
 CONFIG_BT_BUF_ACL_RX_SIZE=60
 CONFIG_BT_BUF_ACL_TX_SIZE=60
+CONFIG_BT_BUF_CMD_TX_SIZE=255
 
 ##
 ## Enabling BT_CTRL_DTM_HCI requires BT_LL_SW_SPLIT which requires BT_CTRL

tests/bluetooth/bsim_bt/edtt_ble_test_app/hci_test_app/prj_dut_llcp.conf

@@ -10,8 +10,10 @@ CONFIG_BT_DEBUG_LOG=y
 CONFIG_BT_ECC=y
 CONFIG_BT_TINYCRYPT_ECC=y
 
+# BUF_CMD_TX_SIZE must be 255 because of HCI/GEV/BV-01-C
 CONFIG_BT_BUF_ACL_RX_SIZE=60
 CONFIG_BT_BUF_ACL_TX_SIZE=60
+CONFIG_BT_BUF_CMD_TX_SIZE=255
 
 ##
 ## Enabling BT_CTRL_DTM_HCI requires BT_LL_SW_SPLIT which requires BT_CTRL

tests/bluetooth/bsim_bt/edtt_ble_test_app/hci_test_app/prj_tst.conf

@@ -8,8 +8,10 @@ CONFIG_BT_DEBUG_LOG=y
 CONFIG_BT_ECC=y
 CONFIG_BT_TINYCRYPT_ECC=y
 
+# BUF_CMD_TX_SIZE must be 255 because of HCI/GEV/BV-01-C
 CONFIG_BT_BUF_ACL_RX_SIZE=60
 CONFIG_BT_BUF_ACL_TX_SIZE=60
+CONFIG_BT_BUF_CMD_TX_SIZE=255
 
 ##
 ## Enabling BT_CTRL_DTM_HCI requires BT_LL_SW which requires BT_CTRL

tests/bluetooth/bsim_bt/edtt_ble_test_app/hci_test_app/prj_tst_llcp.conf

@@ -8,8 +8,10 @@ CONFIG_BT_DEBUG_LOG=y
 CONFIG_BT_ECC=y
 CONFIG_BT_TINYCRYPT_ECC=y
 
+# BUF_CMD_TX_SIZE must be 255 because of HCI/GEV/BV-01-C
 CONFIG_BT_BUF_ACL_RX_SIZE=60
 CONFIG_BT_BUF_ACL_TX_SIZE=60
+CONFIG_BT_BUF_CMD_TX_SIZE=255
 
 ##
 ## Enabling BT_CTRL_DTM_HCI requires BT_LL_SW_SPLIT which requires BT_CTRL