DO NOT MERGE Check size of pin before replying

If a malicious client set a pin that was too long it would overflow
the pin code memory.

Bug: 27411268
Change-Id: I9197ac6fdaa92a4799dacb6364e04671a39450cc

btif/src/btif_dm.c

diff --git a/btif/src/btif_dm.c b/btif/src/btif_dm.c
index 425af22..c7a5ffe 100644
--- a/btif/src/btif_dm.c
+++ b/btif/src/btif_dm.c
@@ -2436,7 +2436,7 @@
                                uint8_t pin_len, bt_pin_code_t *pin_code)
 {
     BTIF_TRACE_EVENT("%s: accept=%d", __FUNCTION__, accept);
-    if (pin_code == NULL)
+    if (pin_code == NULL || pin_len > PIN_CODE_LEN)
         return BT_STATUS_FAIL;
 #if (defined(BLE_INCLUDED) && (BLE_INCLUDED == TRUE))