commit 4cda7b98caf6580b4cc8871155a42fe825a54cc7
author Myles Watson <mylesgw@google.com> Wed Jan 10 09:51:28 2018 -0800
committer android-build-team Robot <android-build-team-robot@google.com> Thu Jan 18 19:42:37 2018 +0000
tree b59c3204aa502cce323e062c3f8cb54c81f3e041
parent 0dd5dc8e3003d5bdd8e75785c86fe401fa84bdfa

PAN: Fix Use-after-free in bta_pan_data_buf_ind_cback

Patch from b/67078939

Test: build
Bug: 67110692
Change-Id: I63b857d031c55d3a0754e4101e330843eb422b2a
(cherry picked from commit 2a18e724b2bf101ea38a5b089de56842107c8369)

bta/pan/bta_pan_act.cc

diff --git a/bta/pan/bta_pan_act.cc b/bta/pan/bta_pan_act.cc
index 0cbb9f7..41e0bf6 100644
--- a/bta/pan/bta_pan_act.cc
+++ b/bta/pan/bta_pan_act.cc
@@ -174,6 +174,11 @@
   tBTA_PAN_SCB* p_scb;
   BT_HDR* p_new_buf;
 
+  p_scb = bta_pan_scb_by_handle(handle);
+  if (p_scb == NULL) {
+    return;
+  }
+
   if (sizeof(tBTA_PAN_DATA_PARAMS) > p_buf->offset) {
     /* offset smaller than data structure in front of actual data */
     if (sizeof(BT_HDR) + sizeof(tBTA_PAN_DATA_PARAMS) + p_buf->len >
@@ -181,7 +186,6 @@
       android_errorWriteLog(0x534e4554, "63146237");
       APPL_TRACE_ERROR("%s: received buffer length too large: %d", __func__,
                        p_buf->len);
-      osi_free(p_buf);
       return;
     }
     p_new_buf = (BT_HDR*)osi_malloc(PAN_BUF_SIZE);
@@ -189,7 +193,6 @@
            (uint8_t*)(p_buf + 1) + p_buf->offset, p_buf->len);
     p_new_buf->len = p_buf->len;
     p_new_buf->offset = sizeof(tBTA_PAN_DATA_PARAMS);
-    osi_free(p_buf);
   } else {
     p_new_buf = p_buf;
   }
@@ -200,12 +203,6 @@
   ((tBTA_PAN_DATA_PARAMS*)p_new_buf)->ext = ext;
   ((tBTA_PAN_DATA_PARAMS*)p_new_buf)->forward = forward;
 
-  p_scb = bta_pan_scb_by_handle(handle);
-  if (p_scb == NULL) {
-    osi_free(p_new_buf);
-    return;
-  }
-
   fixed_queue_enqueue(p_scb->data_queue, p_new_buf);
   BT_HDR* p_event = (BT_HDR*)osi_malloc(sizeof(BT_HDR));
   p_event->layer_specific = handle;

stack/bnep/bnep_main.cc

diff --git a/stack/bnep/bnep_main.cc b/stack/bnep/bnep_main.cc
index 475cc28..cf7a911 100644
--- a/stack/bnep/bnep_main.cc
+++ b/stack/bnep/bnep_main.cc
@@ -601,6 +601,7 @@
   if (bnep_cb.p_data_buf_cb) {
     (*bnep_cb.p_data_buf_cb)(p_bcb->handle, *p_src_addr, *p_dst_addr, protocol,
                              p_buf, fw_ext_present);
+    osi_free(p_buf);
   } else if (bnep_cb.p_data_ind_cb) {
     (*bnep_cb.p_data_ind_cb)(p_bcb->handle, *p_src_addr, *p_dst_addr, protocol,
                              p, rem_len, fw_ext_present);