commit 2d210988322c344b2c95337472bda94e13923f99
author George Chang <georgekgchang@google.com> Fri Aug 16 20:37:23 2019 +0800
committer android-build-team Robot <android-build-team-robot@google.com> Fri Sep 20 02:57:43 2019 +0000
tree 724c02292a57933d49e8b15b3a378cb149bd007d
parent e6e793e4457e6d41c708b4f43c9cb7f1743deb0e

Prevent OOB in rw_i93.cc

Bug: 139188579
Test: Read/Write/Lock Type 5 Tag
Change-Id: Ife24f097c926184019038e559cbd806b289911c6
Exempt-From-Owner-Approval: Old Owners are all transferred to another BU
(cherry picked from commit 4025e2b929905f9b751f3612a6ee26cd5e599417)

src/nfc/tags/rw_i93.cc

diff --git a/src/nfc/tags/rw_i93.cc b/src/nfc/tags/rw_i93.cc
index 46f2bc8..495ee8f 100644
--- a/src/nfc/tags/rw_i93.cc
+++ b/src/nfc/tags/rw_i93.cc
@@ -50,6 +50,8 @@
 #define RW_I93_FORMAT_DATA_LEN 8
 /* max getting lock status if get multi block sec is supported */
 #define RW_I93_GET_MULTI_BLOCK_SEC_SIZE 253
+/*Capability Container CC Size */
+#define RW_I93_CC_SIZE 4
 
 /* main state */
 enum {
@@ -1743,8 +1745,14 @@
 
     case RW_I93_SUBSTATE_WAIT_CC:
 
-      /* assume block size is more than 4 */
-      STREAM_TO_ARRAY(cc, p, 4);
+      if (length < RW_I93_CC_SIZE) {
+        android_errorWriteLog(0x534e4554, "139188579");
+        rw_i93_handle_error(NFC_STATUS_FAILED);
+        return;
+      }
+
+      /* assume block size is more than RW_I93_CC_SIZE 4 */
+      STREAM_TO_ARRAY(cc, p, RW_I93_CC_SIZE);
 
       status = NFC_STATUS_FAILED;
 
@@ -2798,6 +2806,12 @@
   switch (p_i93->sub_state) {
     case RW_I93_SUBSTATE_WAIT_CC:
 
+      if (length < RW_I93_CC_SIZE) {
+        android_errorWriteLog(0x534e4554, "139188579");
+        rw_i93_handle_error(NFC_STATUS_FAILED);
+        return;
+      }
+
       /* mark CC as read-only */
       *(p + 1) |= I93_ICODE_CC_READ_ONLY;