From 3d89c4fb28b44ad5cbc0e75315e28b96eaee95db Mon Sep 17 00:00:00 2001
From: Ted Wang <tedwang@google.com>
Date: Mon, 29 Apr 2019 10:11:04 +0800
Subject: [PATCH] Fix potential OOB read in sdpu_get_len_from_type

Add boundary check in sdpu_get_len_from_type to prevent potential OOB read.

Bug: 117105007
Test: Manul
Merged-In: I3755e13ee0a7e22ffd5f48fca909610a26b09d0a
Change-Id: I3755e13ee0a7e22ffd5f48fca909610a26b09d0a
(cherry picked from commit 1243f8da338dadfe2a3c281a08297b431402d41c)
(cherry picked from commit 4d8e1d63e1a2116c47702d38d858f5a742e8292f)
---
 stack/sdp/sdp_db.c        |  7 ++++++-
 stack/sdp/sdp_discovery.c | 37 ++++++++++++++++++++++++++++---------
 stack/sdp/sdp_utils.c     | 17 ++++++++++++++++-
 stack/sdp/sdpint.h        |  2 +-
 4 files changed, 51 insertions(+), 12 deletions(-)

diff --git a/stack/sdp/sdp_db.c b/stack/sdp/sdp_db.c
index 318a8cc2..f9518f77 100644
--- a/stack/sdp/sdp_db.c
+++ b/stack/sdp/sdp_db.c
@@ -130,7 +130,12 @@ static BOOLEAN find_uuid_in_seq (UINT8 *p , UINT32 seq_len, UINT8 *p_uuid,
     while (p < p_end)
     {
         type = *p++;
-        p = sdpu_get_len_from_type (p, type, &len);
+        p = sdpu_get_len_from_type (p, p_end, type, &len);
+        if (p == NULL || (p + len) > p_end)
+        {
+            SDP_TRACE_WARNING1("%s: bad length", __func__);
+            break;
+        }
         type = type >> 3;
         if (type == UUID_DESC_TYPE)
         {
diff --git a/stack/sdp/sdp_discovery.c b/stack/sdp/sdp_discovery.c
index d92d1e52..81b5d584 100644
--- a/stack/sdp/sdp_discovery.c
+++ b/stack/sdp/sdp_discovery.c
@@ -408,6 +408,7 @@ static void sdp_copy_raw_data (tCONN_CB *p_ccb, BOOLEAN offset)
     UINT32          list_len;
     UINT8           *p;
     UINT8           * p_temp;
+    UINT8           *p_end;
     UINT8           type;
     UINT32          delta_len = 0;
 
@@ -427,13 +428,19 @@ static void sdp_copy_raw_data (tCONN_CB *p_ccb, BOOLEAN offset)
         cpy_len = p_ccb->p_db->raw_size - p_ccb->p_db->raw_used;
         list_len = p_ccb->list_len;
         p_temp = p = &p_ccb->rsp_list[0];
+        p_end = &p_ccb->rsp_list[0] + list_len;
 
         if(offset)
         {
             cpy_len -= 1;
             type = *p++;
             uint8_t* old_p = p;
-            p = sdpu_get_len_from_type (p, type, &list_len);
+            p = sdpu_get_len_from_type(p, p_end, type, &list_len);
+            if (p == NULL || (p + list_len) > p_end)
+            {
+                SDP_TRACE_WARNING1("%s: bad length", __func__);
+                return;
+            }
             if ((int)cpy_len < (p - old_p))
             {
                 SDP_TRACE_WARNING1("%s: no bytes left for data", __func__);
@@ -810,8 +817,12 @@ static void process_service_search_attr_rsp (tCONN_CB *p_ccb, UINT8 *p_reply,
         SDP_TRACE_WARNING1 ("SDP - Wrong type: 0x%02x in attr_rsp", type);
         return;
     }
-    p = sdpu_get_len_from_type (p, type, &seq_len);
-
+    p = sdpu_get_len_from_type(p, p + p_ccb->list_len, type, &seq_len);
+    if (p == NULL || (p + seq_len) > (p + p_ccb->list_len))
+    {
+        SDP_TRACE_WARNING1("%s: bad length", __func__);
+        return;
+    }
     p_end = &p_ccb->rsp_list[p_ccb->list_len];
 
     if ((p + seq_len) != p_end)
@@ -858,9 +869,8 @@ static UINT8 *save_attr_seq (tCONN_CB *p_ccb, UINT8 *p, UINT8 *p_msg_end)
         SDP_TRACE_WARNING1 ("SDP - Wrong type: 0x%02x in attr_rsp", type);
         return (NULL);
     }
-
-    p = sdpu_get_len_from_type (p, type, &seq_len);
-    if ((p + seq_len) > p_msg_end)
+    p = sdpu_get_len_from_type(p, p_msg_end, type, &seq_len);
+    if (p == NULL || (p + seq_len) > p_msg_end)
     {
         SDP_TRACE_WARNING1 ("SDP - Bad len in attr_rsp %d", seq_len);
         return (NULL);
@@ -880,7 +890,12 @@ static UINT8 *save_attr_seq (tCONN_CB *p_ccb, UINT8 *p, UINT8 *p_msg_end)
     {
         /* First get the attribute ID */
         type = *p++;
-        p = sdpu_get_len_from_type (p, type, &attr_len);
+        p = sdpu_get_len_from_type(p, p_msg_end, type, &attr_len);
+        if (p == NULL || (p + attr_len) > p_seq_end)
+        {
+            SDP_TRACE_WARNING2("%s: Bad len in attr_rsp %d", __func__, attr_len);
+            return (NULL);
+        }
         if (((type >> 3) != UINT_DESC_TYPE) || (attr_len != 2))
         {
             SDP_TRACE_WARNING2 ("SDP - Bad type: 0x%02x or len: %d in attr_rsp", type, attr_len);
@@ -970,8 +985,12 @@ static UINT8 *add_attr (UINT8 *p, UINT8 *p_end, tSDP_DISCOVERY_DB *p_db, tSDP_DI
     nest_level &= ~(SDP_ADDITIONAL_LIST_MASK);
 
     type = *p++;
-    p = sdpu_get_len_from_type (p, type, &attr_len);
-
+    p = sdpu_get_len_from_type(p, p_end, type, &attr_len);
+    if (p == NULL || (p + attr_len) > p_end)
+    {
+        SDP_TRACE_WARNING1("%s: bad length in attr_rsp", __func__);
+        return NULL;
+    }
     attr_len &= SDP_DISC_ATTR_LEN_MASK;
     attr_type = (type >> 3) & 0x0f;
 
diff --git a/stack/sdp/sdp_utils.c b/stack/sdp/sdp_utils.c
index 210fbcc8..c99378b8 100644
--- a/stack/sdp/sdp_utils.c
+++ b/stack/sdp/sdp_utils.c
@@ -608,7 +608,7 @@ UINT8 *sdpu_extract_attr_seq (UINT8 *p, UINT16 param_len, tSDP_ATTR_SEQ *p_seq)
 ** Returns          void
 **
 *******************************************************************************/
-UINT8 *sdpu_get_len_from_type (UINT8 *p, UINT8 type, UINT32 *p_len)
+UINT8 *sdpu_get_len_from_type (UINT8 *p, UINT8 *p_end, UINT8 type, UINT32 *p_len)
 {
     UINT8   u8;
     UINT16  u16;
@@ -632,14 +632,29 @@ UINT8 *sdpu_get_len_from_type (UINT8 *p, UINT8 type, UINT32 *p_len)
         *p_len = 16;
         break;
     case SIZE_IN_NEXT_BYTE:
+        if (p + 1 > p_end)
+        {
+            *p_len = 0;
+            return NULL;
+        }
         BE_STREAM_TO_UINT8 (u8, p);
         *p_len = u8;
         break;
     case SIZE_IN_NEXT_WORD:
+        if (p + 2 > p_end)
+        {
+            *p_len = 0;
+            return NULL;
+        }
         BE_STREAM_TO_UINT16 (u16, p);
         *p_len = u16;
         break;
     case SIZE_IN_NEXT_LONG:
+        if (p + 4 > p_end)
+        {
+            *p_len = 0;
+            return NULL;
+        }
         BE_STREAM_TO_UINT32 (u32, p);
         *p_len = (UINT16) u32;
         break;
diff --git a/stack/sdp/sdpint.h b/stack/sdp/sdpint.h
index b3006640..74f748aa 100644
--- a/stack/sdp/sdpint.h
+++ b/stack/sdp/sdpint.h
@@ -285,7 +285,7 @@ extern void      sdpu_build_n_send_error (tCONN_CB *p_ccb, UINT16 trans_num, UIN
 extern UINT8    *sdpu_extract_attr_seq (UINT8 *p, UINT16 param_len, tSDP_ATTR_SEQ *p_seq);
 extern UINT8    *sdpu_extract_uid_seq (UINT8 *p, UINT16 param_len, tSDP_UUID_SEQ *p_seq);
 
-SDP_API extern UINT8    *sdpu_get_len_from_type (UINT8 *p, UINT8 type, UINT32 *p_len);
+SDP_API extern UINT8    *sdpu_get_len_from_type (UINT8 *p, UINT8 *p_end, UINT8 type, UINT32 *p_len);
 extern BOOLEAN  sdpu_is_base_uuid (UINT8 *p_uuid);
 extern BOOLEAN  sdpu_compare_uuid_arrays (UINT8 *p_uuid1, UINT32 len1, UINT8 *p_uuid2, UINT16 len2);
 SDP_API extern BOOLEAN  sdpu_compare_bt_uuids (tBT_UUID *p_uuid1, tBT_UUID *p_uuid2);
