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fix(i2c_master): NULL pointer dereference in i2c_master_bus_destroy when i2c_master->base is NULL #14845

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fix(i2c_master): NULL pointer dereference in i2c_master_bus_destroy when i2c_master->base is NULL #14845

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3dc85d9
fix: check for NULL pointer in i2c_master->base before accessing it
pback34 Nov 7, 2024
a230096
refactor: remove redundnant NULL check for i2c_master handle
pback34 Nov 7, 2024
8567a45
refactor: remove unnecessary else statements
pback34 Nov 8, 2024
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56 changes: 32 additions & 24 deletions components/esp_driver_i2c/i2c_master.c
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Original file line number Diff line number Diff line change
Expand Up @@ -784,40 +784,48 @@ static esp_err_t i2c_master_bus_destroy(i2c_master_bus_handle_t bus_handle)
{
ESP_RETURN_ON_FALSE(bus_handle, ESP_ERR_INVALID_ARG, TAG, "no memory for i2c master bus");
i2c_master_bus_handle_t i2c_master = bus_handle;
i2c_common_deinit_pins(i2c_master->base);
if (i2c_release_bus_handle(i2c_master->base) == ESP_OK) {
if (i2c_master) {
if (i2c_master->bus_lock_mux) {
vSemaphoreDeleteWithCaps(i2c_master->bus_lock_mux);
i2c_master->bus_lock_mux = NULL;
}
if (i2c_master->cmd_semphr) {
vSemaphoreDeleteWithCaps(i2c_master->cmd_semphr);
i2c_master->cmd_semphr = NULL;
}
if (i2c_master->event_queue) {
vQueueDeleteWithCaps(i2c_master->event_queue);
}
if (i2c_master->queues_storage) {
free(i2c_master->queues_storage);
}
free(i2c_master->i2c_async_ops);
for (int i = 0; i < I2C_TRANS_QUEUE_MAX; i++) {
if (i2c_master->trans_queues[i]) {
vQueueDelete(i2c_master->trans_queues[i]);

// Check if i2c_master->base is not NULL before using it
if (i2c_master->base) {
i2c_common_deinit_pins(i2c_master->base);

if (i2c_release_bus_handle(i2c_master->base) == ESP_OK) {
if (i2c_master) {
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this specific check for non-null is redundant at this point since the pointer will have been dereferenced already and has been validated already as part of the first line in the function.

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Good catch. Please see if latest looks correct.

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Looks much better!

if (i2c_master->bus_lock_mux) {
vSemaphoreDeleteWithCaps(i2c_master->bus_lock_mux);
i2c_master->bus_lock_mux = NULL;
}
if (i2c_master->cmd_semphr) {
vSemaphoreDeleteWithCaps(i2c_master->cmd_semphr);
i2c_master->cmd_semphr = NULL;
}
if (i2c_master->event_queue) {
vQueueDeleteWithCaps(i2c_master->event_queue);
}
if (i2c_master->queues_storage) {
free(i2c_master->queues_storage);
}
free(i2c_master->i2c_async_ops);
for (int i = 0; i < I2C_TRANS_QUEUE_MAX; i++) {
if (i2c_master->trans_queues[i]) {
vQueueDelete(i2c_master->trans_queues[i]);
}
}
bus_handle = NULL;
}
bus_handle = NULL;
}

free(i2c_master);
free(i2c_master);
} else {
free(i2c_master);
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Unless the ESP coding style suggests this, I would refactor the free(i2c_master); calls into a single statement at the end end remove two else clauses.

}
} else {
free(i2c_master);
}

return ESP_OK;
}


static esp_err_t s_i2c_asynchronous_transaction(i2c_master_dev_handle_t i2c_dev, i2c_operation_t *i2c_ops, size_t ops_dim, int timeout_ms)
{
i2c_master_bus_t *i2c_master = i2c_dev->master_bus;
Expand Down