Prevent Out of bounds read in llcp code

Modifies llcp_util.cc & llcp_link.cc to fix the OOB issues.

Test: Nfc Enable/Disable, Android Beam, Tag reading
Bug: 114237888
Bug: 114238578
Bug: 111699773
Bug: 111660010
Merged-In: Ie28888ddb9a5a2605ae32a27e3dba01c35ab3913
Change-Id: Ie28888ddb9a5a2605ae32a27e3dba01c35ab3913
(cherry picked from commit 23eb85a028780af14f617e27938540a52c18a8d5)

src/nfc/llcp/llcp_link.cc

diff --git a/src/nfc/llcp/llcp_link.cc b/src/nfc/llcp/llcp_link.cc
index cebabba..8a5ddf2 100644
--- a/src/nfc/llcp/llcp_link.cc
+++ b/src/nfc/llcp/llcp_link.cc
@@ -1131,7 +1131,7 @@
   agf_length = p_agf->len;
   p = (uint8_t*)(p_agf + 1) + p_agf->offset;
 
-  while (agf_length > 0) {
+  while (agf_length >= LLCP_PDU_HEADER_SIZE) {
     /* get length of PDU */
     p_pdu_length = p;
     BE_STREAM_TO_UINT16(pdu_length, p);

src/nfc/llcp/llcp_util.cc

diff --git a/src/nfc/llcp/llcp_util.cc b/src/nfc/llcp/llcp_util.cc
index 8b582d8..973a1b9 100644
--- a/src/nfc/llcp/llcp_util.cc
+++ b/src/nfc/llcp/llcp_util.cc
@@ -26,6 +26,7 @@
 
 #include <android-base/stringprintf.h>
 #include <base/logging.h>
+#include <log/log.h>
 
 #include "bt_types.h"
 #include "gki.h"
@@ -49,20 +50,24 @@
 bool llcp_util_parse_link_params(uint16_t length, uint8_t* p_bytes) {
   uint8_t param_type, param_len, *p = p_bytes;
 
-  while (length) {
+  while (length >= 2) {
     BE_STREAM_TO_UINT8(param_type, p);
-    length--;
+    BE_STREAM_TO_UINT8(param_len, p);
+    if (length < param_len + 2) {
+      android_errorWriteLog(0x534e4554, "114238578");
+      LOG(ERROR) << StringPrintf("Bad LTV's");
+      return false;
+    }
+    length -= param_len + 2;
 
     switch (param_type) {
       case LLCP_VERSION_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT8(llcp_cb.lcb.peer_version, p);
         DLOG_IF(INFO, nfc_debug_enabled)
             << StringPrintf("Peer Version - 0x%02X", llcp_cb.lcb.peer_version);
         break;
 
       case LLCP_MIUX_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT16(llcp_cb.lcb.peer_miu, p);
         llcp_cb.lcb.peer_miu &= LLCP_MIUX_MASK;
         llcp_cb.lcb.peer_miu += LLCP_DEFAULT_MIU;
@@ -71,14 +76,12 @@
         break;
 
       case LLCP_WKS_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT16(llcp_cb.lcb.peer_wks, p);
         DLOG_IF(INFO, nfc_debug_enabled)
             << StringPrintf("Peer WKS - 0x%04X", llcp_cb.lcb.peer_wks);
         break;
 
       case LLCP_LTO_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT8(llcp_cb.lcb.peer_lto, p);
         llcp_cb.lcb.peer_lto *= LLCP_LTO_UNIT; /* 10ms unit */
         DLOG_IF(INFO, nfc_debug_enabled)
@@ -86,7 +89,6 @@
         break;
 
       case LLCP_OPT_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT8(llcp_cb.lcb.peer_opt, p);
         DLOG_IF(INFO, nfc_debug_enabled)
             << StringPrintf("Peer OPT - 0x%02X", llcp_cb.lcb.peer_opt);
@@ -94,17 +96,9 @@
 
       default:
         LOG(ERROR) << StringPrintf("Unexpected type 0x%x", param_type);
-        BE_STREAM_TO_UINT8(param_len, p);
         p += param_len;
         break;
     }
-
-    if (length >= param_len + 1)
-      length -= param_len + 1;
-    else {
-      LOG(ERROR) << StringPrintf("Bad LTV's");
-      return false;
-    }
   }
   return true;
 }
@@ -474,13 +468,19 @@
   p_params->sn[0] = 0;
   p_params->sn[1] = 0;
 
-  while (length) {
+  while (length >= 2) {
     BE_STREAM_TO_UINT8(param_type, p);
-    length--;
+    BE_STREAM_TO_UINT8(param_len, p);
+    /* check remaining lengh */
+    if (length < param_len + 2) {
+      android_errorWriteLog(0x534e4554, "111660010");
+      LOG(ERROR) << StringPrintf("Bad LTV's");
+      return LLCP_STATUS_FAIL;
+    }
+    length -= param_len + 2;
 
     switch (param_type) {
       case LLCP_MIUX_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT16(p_params->miu, p);
         p_params->miu &= LLCP_MIUX_MASK;
         p_params->miu += LLCP_DEFAULT_MIU;
@@ -490,7 +490,6 @@
         break;
 
       case LLCP_RW_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT8(p_params->rw, p);
         p_params->rw &= 0x0F;
 
@@ -499,8 +498,6 @@
         break;
 
       case LLCP_SN_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
-
         if (param_len == 0) {
           /* indicate that SN type is included without SN */
           p_params->sn[1] = LLCP_SN_TYPE;
@@ -519,18 +516,9 @@
 
       default:
         LOG(ERROR) << StringPrintf("Unexpected type 0x%x", param_type);
-        BE_STREAM_TO_UINT8(param_len, p);
         p += param_len;
         break;
     }
-
-    /* check remaining lengh */
-    if (length >= param_len + 1) {
-      length -= param_len + 1;
-    } else {
-      LOG(ERROR) << StringPrintf("Bad LTV's");
-      return LLCP_STATUS_FAIL;
-    }
   }
   return LLCP_STATUS_SUCCESS;
 }
@@ -607,13 +595,18 @@
   *p_miu = LLCP_DEFAULT_MIU;
   *p_rw = LLCP_DEFAULT_RW;
 
-  while (length) {
+  while (length >= 2) {
     BE_STREAM_TO_UINT8(param_type, p);
-    length--;
+    BE_STREAM_TO_UINT8(param_len, p);
+    if (length < param_len + 2) {
+      android_errorWriteLog(0x534e4554, "114237888");
+      LOG(ERROR) << StringPrintf("Bad LTV's");
+      return LLCP_STATUS_FAIL;
+    }
+    length -= param_len + 2;
 
     switch (param_type) {
       case LLCP_MIUX_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT16((*p_miu), p);
         (*p_miu) &= LLCP_MIUX_MASK;
         (*p_miu) += LLCP_DEFAULT_MIU;
@@ -623,7 +616,6 @@
         break;
 
       case LLCP_RW_TYPE:
-        BE_STREAM_TO_UINT8(param_len, p);
         BE_STREAM_TO_UINT8((*p_rw), p);
         (*p_rw) &= 0x0F;
 
@@ -633,17 +625,9 @@
 
       default:
         LOG(ERROR) << StringPrintf("Unexpected type 0x%x", param_type);
-        BE_STREAM_TO_UINT8(param_len, p);
         p += param_len;
         break;
     }
-
-    if (length >= param_len + 1)
-      length -= param_len + 1;
-    else {
-      LOG(ERROR) << StringPrintf("Bad LTV's");
-      return LLCP_STATUS_FAIL;
-    }
   }
   return LLCP_STATUS_SUCCESS;
 }