Bluetooth: Enforce zero-valued hash/rand192 for LE OOB

Until legacy SMP OOB pairing is implemented user space should be given a
clear error when trying to use it. This patch adds a corresponding check
to the Add Remote OOB Data handler function which returns "invalid
parameters" if non-zero Rand192 or Hash192 parameters were given for an
LE address.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 25e40e82b9a2..8417ab387d1a 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -131,6 +131,9 @@ static const u16 mgmt_events[] = {
 
 #define CACHE_TIMEOUT   msecs_to_jiffies(2 * 1000)
 
+#define ZERO_KEY "\x00\x00\x00\x00\x00\x00\x00\x00" \
+                 "\x00\x00\x00\x00\x00\x00\x00\x00"
+
 struct pending_cmd {
         struct list_head list;
         u16 opcode;
@@ -3673,6 +3676,18 @@ static int add_remote_oob_data(struct sock *sk, struct hci_dev *hdev,
                 u8 status;
 
                 if (bdaddr_type_is_le(cp->addr.type)) {
+                        /* Enforce zero-valued 192-bit parameters as
+                         * long as legacy SMP OOB isn't implemented.
+                         */
+                        if (memcmp(cp->rand192, ZERO_KEY, 16) ||
+                            memcmp(cp->hash192, ZERO_KEY, 16)) {
+                                err = cmd_complete(sk, hdev->id,
+                                                   MGMT_OP_ADD_REMOTE_OOB_DATA,
+                                                   MGMT_STATUS_INVALID_PARAMS,
+                                                   addr, sizeof(*addr));
+                                goto unlock;
+                        }
+
                         rand192 = NULL;
                         hash192 = NULL;
                 } else {