From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: tyiu Date: Tue, 28 Mar 2023 18:40:51 +0000 Subject: [PATCH] Fix gatt_end_operation buffer overflow Added boundary check for gatt_end_operation to prevent writing out of boundary. Since response of the GATT server is handled in gatt_client_handle_server_rsp() and gatt_process_read_rsp(), the maximum lenth that can be passed into the handlers is bounded by GATT_MAX_MTU_SIZE, which is set to 517, which is greater than GATT_MAX_ATTR_LEN which is set to 512. The fact that there is no spec that gaurentees MTU response to be less than or equal to 512 bytes can cause a buffer overflow when performing memcpy without length check. Bug: 261068592 Test: No test since not affecting behavior Tag: #security Ignore-AOSP-First: security (cherry picked from https://googleplex-android-review.googlesource.com/q/commit:dd7298e982e4bbf0138a490562679c9a4a755200) Merged-In: I49e2797cd9300ee4cd69f2c7fa5f0073db78b873 Change-Id: I49e2797cd9300ee4cd69f2c7fa5f0073db78b873 --- stack/gatt/gatt_utils.cc | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/stack/gatt/gatt_utils.cc b/stack/gatt/gatt_utils.cc index e7cc76286..084b13c2e 100644 --- a/stack/gatt/gatt_utils.cc +++ b/stack/gatt/gatt_utils.cc @@ -1326,6 +1326,13 @@ void gatt_end_operation(tGATT_CLCB* p_clcb, tGATT_STATUS status, void* p_data) { cb_data.att_value.handle = p_clcb->s_handle; cb_data.att_value.len = p_clcb->counter; + if (cb_data.att_value.len > GATT_MAX_ATTR_LEN) { + LOG(WARNING) << __func__ + << StringPrintf(" Large cb_data.att_value, size=%d", + cb_data.att_value.len); + cb_data.att_value.len = GATT_MAX_ATTR_LEN; + } + if (p_data && p_clcb->counter) memcpy(cb_data.att_value.value, p_data, cb_data.att_value.len); }