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Date:   Wed, 19 Feb 2020 14:45:19 +0800
Message-Id: <20200219144442.Bluez.v2.1.I145f6c5bbf2437a6f6afc28d3db2b876c034c2d8@changeid>
Mime-Version: 1.0
Subject: [Bluez PATCH v2] bluetooth: fix passkey uninitialized when used
From:   Howard Chung <howardchung@google.com>
To:     linux-bluetooth@vger.kernel.org, marcel@holtmann.org
Cc:     chromeos-bluetooth-upstreaming@chromium.org,
        Howard Chung <howardchung@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jakub Kicinski <kuba@kernel.org>,
        clang-built-linux@googlegroups.com
Content-Type: text/plain; charset="UTF-8"
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

This issue cause a warning here
https://groups.google.com/forum/#!topic/clang-built-linux/kyRKCjRsGoU

Signed-off-by: Howard Chung <howardchung@google.com>

---

Changes in v2:
- refactor code

 net/bluetooth/smp.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 50e0ac692ec4..929e0bebaf80 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -2115,7 +2115,7 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 	struct l2cap_chan *chan = conn->smp;
 	struct smp_chan *smp = chan->data;
 	struct hci_conn *hcon = conn->hcon;
-	u8 *pkax, *pkbx, *na, *nb;
+	u8 *pkax, *pkbx, *na, *nb, confirm_hint;
 	u32 passkey;
 	int err;
 
@@ -2179,13 +2179,12 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 		 */
 		if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
 				 hcon->role)) {
-			err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
-							hcon->type,
-							hcon->dst_type,
-							passkey, 1);
-			if (err)
-				return SMP_UNSPECIFIED;
-			set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
+			/* Set passkey to 0. The value can be any number since
+			 * it'll be ignored anyway.
+			 */
+			passkey = 0;
+			confirm_hint = 1;
+			goto confirm;
 		}
 	}
 
@@ -2206,9 +2205,11 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 	err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
 	if (err)
 		return SMP_UNSPECIFIED;
+	confirm_hint = 0;
 
+confirm:
 	err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
-					hcon->dst_type, passkey, 0);
+					hcon->dst_type, passkey, confirm_hint);
 	if (err)
 		return SMP_UNSPECIFIED;
 
-- 
2.25.0.265.gbab2e86ba0-goog