Don't drop EspWifiPacketBuffer in a critical section

esp-wifi/src/wifi/mod.rs

@@ -645,23 +645,27 @@ unsafe extern "C" fn recv_cb(
     len: u16,
     eb: *mut c_types::c_void,
 ) -> esp_err_t {
-    critical_section::with(|cs| {
+    let result = critical_section::with(|cs| {
         let packet = EspWifiPacketBuffer { buffer, len, eb };
 
-        match DATA_QUEUE_RX.borrow_ref_mut(cs).enqueue(packet) {
-            Ok(_) => {
-                #[cfg(feature = "embassy-net")]
-                embassy::RECEIVE_WAKER.wake();
+        DATA_QUEUE_RX.borrow_ref_mut(cs).enqueue(packet)
+    });
 
-                include::ESP_OK as esp_err_t
-            }
+    // We must handle the result outside of the critical section because
+    // EspWifiPacketBuffer::drop must not be called in a critical section
+    match result {
+        Ok(_) => {
+            #[cfg(feature = "embassy-net")]
+            embassy::RECEIVE_WAKER.wake();
 
-            _ => {
-                debug!("RX QUEUE FULL");
-                include::ESP_ERR_NO_MEM as esp_err_t
-            }
+            include::ESP_OK as esp_err_t
+        }
+
+        Err(_) => {
+            debug!("RX QUEUE FULL");
+            include::ESP_ERR_NO_MEM as esp_err_t
         }
-    })
+    }
 }
 
 pub(crate) static WIFI_TX_INFLIGHT: AtomicUsize = AtomicUsize::new(0);
@@ -1026,18 +1030,21 @@ fn rx_token_consume<R, F>(f: F) -> R
 where
     F: FnOnce(&mut [u8]) -> R,
 {
-    critical_section::with(|cs| {
+    let mut data = critical_section::with(|cs| {
         let mut queue = DATA_QUEUE_RX.borrow_ref_mut(cs);
 
-        let mut data = unwrap!(
+        unwrap!(
             queue.dequeue(),
             "unreachable: transmit()/receive() ensures there is a packet to process"
-        );
-        let buffer = data.as_slice_mut();
-        dump_packet_info(&buffer);
+        )
+    });
+
+    // We handle the received data outside of the critical section because
+    // EspWifiPacketBuffer::drop must not be called in a critical section
+    let buffer = data.as_slice_mut();
+    dump_packet_info(&buffer);
 
-        f(buffer)
-    })
+    f(buffer)
 }
 
 fn tx_token_consume<R, F>(len: usize, f: F) -> R