From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date: Wed, 10 Mar 2021 22:13:08 +0000 (-0800)
Subject: Bluetooth: SMP: Fail if remote and local public keys are identical
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6d19628f539fccf899298ff02ee4c73e4bf6df3f;p=linux.git

Bluetooth: SMP: Fail if remote and local public keys are identical

This fails the pairing procedure when both remote and local non-debug
public keys are identical.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
---

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index b0c1ee110eff9..e03cc284161c4 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -2732,6 +2732,15 @@ static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
 	if (skb->len < sizeof(*key))
 		return SMP_INVALID_PARAMS;
 
+	/* Check if remote and local public keys are the same and debug key is
+	 * not in use.
+	 */
+	if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) &&
+	    !crypto_memneq(key, smp->local_pk, 64)) {
+		bt_dev_err(hdev, "Remote and local public keys are identical");
+		return SMP_UNSPECIFIED;
+	}
+
 	memcpy(smp->remote_pk, key, 64);
 
 	if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {