From 6d19628f539fccf899298ff02ee4c73e4bf6df3f Mon Sep 17 00:00:00 2001

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Date: Wed, 10 Mar 2021 14:13:08 -0800

Subject: [PATCH] Bluetooth: SMP: Fail if remote and local public keys are identical

Git-commit: 6d19628f539fccf899298ff02ee4c73e4bf6df3f

Patch-mainline: v5.13-rc1

References: git-fixes

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>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 net/bluetooth/smp.c | 9 +++++++++

 1 file changed, 9 insertions(+)

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c

index b0c1ee110eff..e03cc284161c 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)) {

-- 

2.26.2