DO NOT MERGE: Add missing AVRCP message length checks inside avrc_msg_cback

Explicitly check the length of the received message before
accessing the data.

Bug: 111803925
Bug: 79883824
Test: POC scripts
Change-Id: I50d1d1f7dd7038ffcd5f0d5975ab1db43178067f
Merged-In: I00b1c6bd6dd7e18ac2c469ef2032c7ff10dcaecb
(cherry picked from commit b78d265f362dab7df559883617dd766bcc60ad43)

diff --git a/stack/avrc/avrc_api.c b/stack/avrc/avrc_api.c
index e612031..17c8597 100644 (file)
--- a/stack/avrc/avrc_api.c
+++ b/stack/avrc/avrc_api.c
@@ -24,6 +24,8 @@
 #include <assert.h>
 #include <string.h>
 
+#include <log/log.h>
+
 #include "bt_common.h"
 #include "avrc_api.h"
 #include "avrc_int.h"
@@ -565,6 +567,13 @@ static void avrc_msg_cback(UINT8 handle, UINT8 label, UINT8 cr,
     p_data  = (UINT8 *)(p_pkt+1) + p_pkt->offset;
     memset(&msg, 0, sizeof(tAVRC_MSG) );
     {
+        if (p_pkt->len < AVRC_AVC_HDR_SIZE) {
+            android_errorWriteLog(0x534e4554, "111803925");
+            AVRC_TRACE_WARNING("%s: message length %d too short: must be at least %d",
+                               __func__, p_pkt->len, AVRC_AVC_HDR_SIZE);
+            osi_free(p_pkt);
+            return;
+        }
         msg.hdr.ctype           = p_data[0] & AVRC_CTYPE_MASK;
         AVRC_TRACE_DEBUG("avrc_msg_cback handle:%d, ctype:%d, offset:%d, len: %d",
                 handle, msg.hdr.ctype, p_pkt->offset, p_pkt->len);
@@ -603,6 +612,15 @@ static void avrc_msg_cback(UINT8 handle, UINT8 label, UINT8 cr,
             else
             {
                 /* parse response */
+                if (p_pkt->len < AVRC_OP_UNIT_INFO_RSP_LEN) {
+                    AVRC_TRACE_WARNING(
+                        "%s: message length %d too short: must be at least %d",
+                        __func__, p_pkt->len, AVRC_OP_UNIT_INFO_RSP_LEN);
+                    android_errorWriteLog(0x534e4554, "79883824");
+                    drop = TRUE;
+                    p_drop_msg = "UNIT_INFO_RSP too short";
+                    break;
+                }
                 p_data += 4; /* 3 bytes: ctype, subunit*, opcode + octet 3 (is 7)*/
                 msg.unit.unit_type  = (*p_data & AVRC_SUBTYPE_MASK) >> AVRC_SUBTYPE_SHIFT;
                 msg.unit.unit       = *p_data & AVRC_SUBID_MASK;
@@ -634,6 +652,15 @@ static void avrc_msg_cback(UINT8 handle, UINT8 label, UINT8 cr,
             else
             {
                 /* parse response */
+                if (p_pkt->len < AVRC_OP_SUB_UNIT_INFO_RSP_LEN) {
+                    AVRC_TRACE_WARNING(
+                        "%s: message length %d too short: must be at least %d",
+                        __func__, p_pkt->len, AVRC_OP_SUB_UNIT_INFO_RSP_LEN);
+                    android_errorWriteLog(0x534e4554, "79883824");
+                    drop = TRUE;
+                    p_drop_msg = "SUB_UNIT_INFO_RSP too short";
+                    break;
+                }
                 p_data += AVRC_AVC_HDR_SIZE; /* 3 bytes: ctype, subunit*, opcode */
                 msg.sub.page    = (*p_data++ >> AVRC_SUB_PAGE_SHIFT) & AVRC_SUB_PAGE_MASK;
                 xx      = 0;