[48/50] incubator-mynewt-core git commit: Fix invalid memory accesses in ble_uuid_cmp

[ma...@apache.org]

Fix invalid memory accesses in ble_uuid_cmp

When the two uuid values differ in type, one of two things can happen:

1. Access to unallocated or uninitialised memory
2. Unaligned access to 16/32-bit values

Both of these cause crashes, so always make sure we are comparing like types.


Project: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/commit/69588392
Tree: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/tree/69588392
Diff: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/diff/69588392

Branch: refs/heads/1_0_0_dev
Commit: 69588392a5d86b41c47bb0e863138feb1c14fe76
Parents: 0dc1c2b
Author: Simon Ratner <si...@probablyprime.net>
Authored: Sat Mar 4 12:02:40 2017 -0800
Committer: Marko Kiiskila <ma...@runtime.io>
Committed: Mon Mar 6 15:54:25 2017 -0800

----------------------------------------------------------------------
 net/nimble/host/src/ble_uuid.c | 4 ++++
 1 file changed, 4 insertions(+)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/blob/69588392/net/nimble/host/src/ble_uuid.c
----------------------------------------------------------------------
diff --git a/net/nimble/host/src/ble_uuid.c b/net/nimble/host/src/ble_uuid.c
index 028e227..f9ccc6d 100644
--- a/net/nimble/host/src/ble_uuid.c
+++ b/net/nimble/host/src/ble_uuid.c
@@ -76,6 +76,10 @@ ble_uuid_cmp(const ble_uuid_t *uuid1, const ble_uuid_t *uuid2)
     BLE_HS_DBG_ASSERT(verify_uuid(uuid1) == 0);
     BLE_HS_DBG_ASSERT(verify_uuid(uuid2) == 0);
 
+    if (uuid1->type != uuid2->type) {
+      return uuid1->type - uuid2->type;
+    }
+
     switch (uuid1->type) {
     case BLE_UUID_TYPE_16:
         return (int) BLE_UUID16(uuid1)->value - (int) BLE_UUID16(uuid2)->value;