commit cb4844800cb05df1279e2c2934d852aa28e71aec
author Jack Yu <jackcwyu@google.com> Fri Feb 01 15:48:03 2019 -0800
committer android-build-team Robot <android-build-team-robot@google.com> Thu Feb 14 16:24:57 2019 +0000
tree 6c47f49870272bf7ddd1d2cba8c64ec7d430461f
parent acfd93194bfcf3452c01d980f4add91118906586

Prevent OOB error in rw_i93_sm_update_ndef() am: 8617cbb1a8 am: 8081839dc8
am: c80b838093

Change-Id: I8a102085d7ecfeb977d742ebc742e364752cc1b8
(cherry picked from commit c23e375317d638701d1f0c289c85b153ec461082)

src/nfc/tags/rw_i93.cc

diff --git a/src/nfc/tags/rw_i93.cc b/src/nfc/tags/rw_i93.cc
index fabfc10..bcc6421 100644
--- a/src/nfc/tags/rw_i93.cc
+++ b/src/nfc/tags/rw_i93.cc
@@ -2090,6 +2090,12 @@
       "sub_state:%s (0x%x)",
       rw_i93_get_sub_state_name(p_i93->sub_state).c_str(), p_i93->sub_state);
 
+  if (length == 0 || p_i93->block_size > I93_MAX_BLOCK_LENGH) {
+    android_errorWriteLog(0x534e4554, "122320256");
+    rw_i93_handle_error(NFC_STATUS_FAILED);
+    return;
+  }
+
   STREAM_TO_UINT8(flags, p);
   length--;
 
@@ -2114,6 +2120,12 @@
       /* get offset of length field */
       length_offset = (p_i93->ndef_tlv_start_offset + 1) % p_i93->block_size;
 
+      if (length < length_offset) {
+        android_errorWriteLog(0x534e4554, "122320256");
+        rw_i93_handle_error(NFC_STATUS_FAILED);
+        return;
+      }
+
       /* set length to zero */
       *(p + length_offset) = 0x00;
 
@@ -2127,6 +2139,11 @@
 
         /* write the first part of NDEF in the same block */
         for (; xx < p_i93->block_size; xx++) {
+          if (xx > length || p_i93->rw_length > p_i93->ndef_length) {
+            android_errorWriteLog(0x534e4554, "122320256");
+            rw_i93_handle_error(NFC_STATUS_FAILED);
+            return;
+          }
           if (p_i93->rw_length < p_i93->ndef_length) {
             *(p + xx) = *(p_i93->p_update_data + p_i93->rw_length++);
           } else {
@@ -2273,6 +2290,12 @@
 
           /* update length field within the read block */
           for (xx = length_offset; xx < p_i93->block_size; xx++) {
+            if (xx > length) {
+              android_errorWriteLog(0x534e4554, "122320256");
+              rw_i93_handle_error(NFC_STATUS_FAILED);
+              return;
+            }
+
             if (p_i93->rw_length == 3)
               *(p + xx) = 0xFF;
             else if (p_i93->rw_length == 2)