Zephyr - K_FIFO Crash - c

Question

I have a strange error in the k_fifo-useage:
Basis is the project "peripheral uart" from nordic
I want to answer on specific commands send via bluetooth
static void bt_receive_cb(struct bt_conn *conn, const uint8_t *const data,
uint16_t len)
{
int err;
char addr[BT_ADDR_LE_STR_LEN] = {0};
struct answer_buffer_t *buf;
uint8_t answer[UART_BUF_SIZE];
bt_addr_le_to_str(bt_conn_get_dst(conn), addr, ARRAY_SIZE(addr));
LOG_INF("Received %i data %s from: %s", len, data, log_strdup(addr));
if (strncmp(data, "&I", 2) == 0 )
{
uint8_t stringbuffer[100];
buf = k_malloc(sizeof(*buf));
iCounter++;
LOG_INF("&I %i", iCounter);
buf->len = sprintf(stringbuffer, "&I %i\n", iCounter);
memcpy(stringbuffer, &buf, buf->len);
k_fifo_put(&answer_buffer, buf);
}
}
And the bluetooth-sender-thread:
void ble_write_thread(void)
{
/* Don't go any further until BLE is initialized */
k_sem_take(&ble_init_ok, K_FOREVER);
for (;;) {
/* Wait indefinitely for data to be sent over bluetooth */
struct answer_buffer_t *buf = k_fifo_get(&answer_buffer,
K_FOREVER);
if (bt_nus_send(NULL, buf->data, buf->len)) {
LOG_WRN("Failed to send data over BLE connection");
}
k_free(buf);
}
}
K_THREAD_DEFINE(ble_write_thread_id, STACKSIZE, ble_write_thread, NULL, NULL,
NULL, PRIORITY, 0, 0);
But when I send "&I" zephyr crashes:
[00:00:34.164,001] [0m<inf> peripheral_uart: &I 1[0m
[00:00:35.179,046] [1;31m<err> os: r0/a1: 0x00000004 r1/a2: 0x000000d1 r2/a3: 0x00000001[0m
[00:00:35.179,046] [1;31m<err> os: r3/a4: 0x0001dbbd r12/ip: 0x00000000 r14/lr: 0x00011d2b[0m
[00:00:35.179,046] [1;31m<err> os: xpsr: 0x41000000[0m
[00:00:35.179,046] [1;31m<err> os: Faulting instruction address (r15/pc): 0x00028d2c[0m
[00:00:35.179,077] [1;31m<err> os: >>> ZEPHYR FATAL ERROR 4: Kernel panic on CPU 0[0m
[00:00:35.179,077] [1;31m<err> os: Current thread: 0x200017c8 (unknown)[0m
[00:00:35.376,464] [1;31m<err> fatal_error: Resetting system[0m
What do I do wrong?

Answer 1

I found out this line:
LOG_INF("Received %i data %s from: %s", len, data, log_strdup(addr));
Without this its working but i had another error here (caused by my try and arror):
This is the right code:
if (strncmp(data, "&I", 2) == 0 )
{
buf = k_malloc(sizeof(*buf));
iCounter++;
LOG_INF("&I %i", iCounter);
buf->len = sprintf(buf->data, "&I %i\n", iCounter);
k_fifo_put(&answer_buffer, buf);
}