From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: William Escande <wescande@google.com>
Date: Mon, 2 May 2022 09:48:59 -0700
Subject: [PATCH] Check Avrcp packet vendor length before extracting length

Bug: 205571133
Test: build + ag/18105403 for sts test
Ignore-AOSP-First: Security vulnerability
Change-Id: Ic9fa9400ab15785cfdb251af66b1867daf09570e
(cherry picked from commit 003e42896493afb7a0cd7406720987725d4e9da3)
Merged-In: Ic9fa9400ab15785cfdb251af66b1867daf09570e
---
 stack/avrc/avrc_pars_tg.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/stack/avrc/avrc_pars_tg.cc b/stack/avrc/avrc_pars_tg.cc
index 88b8d0083..7042f4da7 100644
--- a/stack/avrc/avrc_pars_tg.cc
+++ b/stack/avrc/avrc_pars_tg.cc
@@ -44,6 +44,12 @@ static tAVRC_STS avrc_ctrl_pars_vendor_cmd(tAVRC_MSG_VENDOR* p_msg,
                                            tAVRC_COMMAND* p_result) {
   tAVRC_STS status = AVRC_STS_NO_ERROR;
 
+  if (p_msg->vendor_len < 4) {  // 4 == pdu + reserved byte + len as uint16
+    AVRC_TRACE_WARNING("%s: message length %d too short: must be at least 4",
+                       __func__, p_msg->vendor_len);
+    android_errorWriteLog(0x534e4554, "205571133");
+    return AVRC_STS_INTERNAL_ERR;
+  }
   uint8_t* p = p_msg->p_vendor_data;
   p_result->pdu = *p++;
   AVRC_TRACE_DEBUG("%s pdu:0x%x", __func__, p_result->pdu);
