From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Venkata Jagadeesh Garaga <quic_vgaraga@quicinc.com>
Date: Tue, 22 Mar 2022 13:35:43 +0530
Subject: [PATCH] Fix OOB in reassemble_and_dispatch

Fix OOB while reading L2cap length in HCI pkt

Change-Id: I7f32b171e8c68b9724f95fcf2327959539e2d0d5
CRs-Fixed: 3155132
---
 hci/src/packet_fragmenter.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/hci/src/packet_fragmenter.c b/hci/src/packet_fragmenter.c
index f1d302238..b2ebefe0e 100644
--- a/hci/src/packet_fragmenter.c
+++ b/hci/src/packet_fragmenter.c
@@ -130,12 +130,10 @@ static void reassemble_and_dispatch(UNUSED_ATTR BT_HDR *packet) {
   if ((packet->event & MSG_EVT_MASK) == MSG_HC_TO_STACK_HCI_ACL) {
     uint8_t *stream = packet->data;
     uint16_t handle;
-    uint16_t l2cap_length;
     uint16_t acl_length;
 
     STREAM_TO_UINT16(handle, stream);
     STREAM_TO_UINT16(acl_length, stream);
-    STREAM_TO_UINT16(l2cap_length, stream);
 
     assert(acl_length == packet->len - HCI_ACL_PREAMBLE_SIZE);
 
@@ -166,6 +164,9 @@ static void reassemble_and_dispatch(UNUSED_ATTR BT_HDR *packet) {
         return;
       }
 
+      uint16_t l2cap_length;
+      STREAM_TO_UINT16(l2cap_length, stream);
+
       uint16_t full_length = l2cap_length + L2CAP_HEADER_SIZE + HCI_ACL_PREAMBLE_SIZE;
 
       // Check for buffer overflow and that the full packet size + BT_HDR size is less than
