From 277e9e0cee35fd626abe5a5c98aa9f35736f18a5 Mon Sep 17 00:00:00 2001 From: Jakub Pawlowski Date: Wed, 23 May 2018 10:19:53 -0700 Subject: [PATCH] GATT: Handle too short Error Response PDU Since the spec is not clear what to do in this case, use one of reserved error codes as a failure reason, and pass it to upper layers. Bug: 79591688 Change-Id: Ie6a53e9c8e4ceb8f1e5a75aee44baa5f4a798c4f Merged-In: Ie6a53e9c8e4ceb8f1e5a75aee44baa5f4a798c4f (cherry picked from commit f63c4b652b3231c2b4907bffd13410c6eb2aa760) --- stack/gatt/gatt_cl.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/stack/gatt/gatt_cl.c b/stack/gatt/gatt_cl.c index 433a2f1dc..cace008d3 100644 --- a/stack/gatt/gatt_cl.c +++ b/stack/gatt/gatt_cl.c @@ -31,6 +31,7 @@ #include "bt_common.h" #include "gatt_int.h" #include "l2c_int.h" +#include "osi/include/log.h" #define GATT_WRITE_LONG_HDR_SIZE 5 /* 1 opcode + 2 handle + 2 offset */ #define GATT_READ_CHAR_VALUE_HDL (GATT_READ_CHAR_VALUE | 0x80) @@ -566,9 +567,27 @@ void gatt_process_error_rsp(tGATT_TCB *p_tcb, tGATT_CLCB *p_clcb, UINT8 op_code, UNUSED(len); GATT_TRACE_DEBUG("gatt_process_error_rsp "); - STREAM_TO_UINT8(opcode, p); - STREAM_TO_UINT16(handle, p); - STREAM_TO_UINT8(reason, p); + + if (len < 4) + { + android_errorWriteLog(0x534e4554, "79591688"); + ALOGE("Error response too short"); + // Specification does not clearly define what should happen if error + // response is too short. General rule in BT Spec 5.0 Vol 3, Part F 3.4.1.1 + // is: "If an error code is received in the Error Response that is not + // understood by the client, for example an error code that was reserved for + // future use that is now being used in a future version of this + // specification, then the Error Response shall still be considered to state + // that the given request cannot be performed for an unknown reason." + opcode = handle = 0; + reason = 0x7F; + } + else + { + STREAM_TO_UINT8(opcode, p); + STREAM_TO_UINT16(handle, p); + STREAM_TO_UINT8(reason, p); + } if (p_clcb->operation == GATTC_OPTYPE_DISCOVERY) { -- 2.11.0