Bluetooth: SMP: Fix setting unknown auth_req bits

commit 065a13e2cc665f6547dc7e8a9d6b6565badf940a upstream.

When sending a pairing request or response we should not just blindly
copy the value that the remote device sent. Instead we should at least
make sure to mask out any unknown bits. This is particularly critical
from the upcoming LE Secure Connections feature perspective as
incorrectly indicating support for it (by copying the remote value)
would cause a failure to pair with devices that support it.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index c27b4e325e3f0ada7704557de18cceaa4185e3da..1849ee08fde56a3396ae03ac922d087739839944 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -30,6 +30,8 @@
 
 #define SMP_TIMEOUT 30000 /* 30 seconds */
 
+#define AUTH_REQ_MASK   0x07
+
 static inline void swap128(u8 src[16], u8 dst[16])
 {
        int i;
@@ -206,7 +208,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
                req->max_key_size = SMP_MAX_ENC_KEY_SIZE;
                req->init_key_dist = dist_keys;
                req->resp_key_dist = dist_keys;
-               req->auth_req = authreq;
+               req->auth_req = (authreq & AUTH_REQ_MASK);
                return;
        }
 
@@ -215,7 +217,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
        rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE;
        rsp->init_key_dist = req->init_key_dist & dist_keys;
        rsp->resp_key_dist = req->resp_key_dist & dist_keys;
-       rsp->auth_req = authreq;
+       rsp->auth_req = (authreq & AUTH_REQ_MASK);
 }
 
 static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)