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From:   Sonny Sasaka <sonnysasaka@chromium.org>
Date:   Fri, 27 Mar 2020 17:09:29 -0700
Message-ID: <CAOxioNnvHMgHyVxbt2Oj+FeHcOT8MdxYtuv_s0PPd_YzkvuxGg@mail.gmail.com>
Subject: [PATCH] Bluetooth: Always request for user confirmation for Just Works
To:     BlueZ <linux-bluetooth@vger.kernel.org>
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Sender: linux-bluetooth-owner@vger.kernel.org
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To improve security, always give the user-space daemon a chance to
accept or reject a Just Works pairing (LE). The daemon may decide to
auto-accept based on the user's intent.

Signed-off-by: Sonny Sasaka <sonnysasaka@chromium.org>
---
 net/bluetooth/smp.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 1476a91ce935..d0b695ee49f6 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -855,6 +855,7 @@ static int tk_request(struct l2cap_conn *conn, u8
remote_oob, u8 auth,
  struct smp_chan *smp = chan->data;
  u32 passkey = 0;
  int ret = 0;
+ int err;

  /* Initialize key for JUST WORKS */
  memset(smp->tk, 0, sizeof(smp->tk));
@@ -883,9 +884,16 @@ static int tk_request(struct l2cap_conn *conn, u8
remote_oob, u8 auth,
     hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
  smp->method = JUST_WORKS;

- /* If Just Works, Continue with Zero TK */
+ /* If Just Works, Continue with Zero TK and ask user-space for
+ * confirmation */
  if (smp->method == JUST_WORKS) {
- set_bit(SMP_FLAG_TK_VALID, &smp->flags);
+ 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);
  return 0;
  }

-- 
2.17.1