[lvc-project] [PATCH 5.10/5.15] Bluetooth: hci_event: Align BR/EDR JUST_WORKS paring with LE

[Nikita Zhandarovich]

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

commit b25e11f978b63cb7857890edb3a698599cddb10e upstream.

This aligned BR/EDR JUST_WORKS method with LE which since 92516cd97fd4
("Bluetooth: Always request for user confirmation for Just Works")
always request user confirmation with confirm_hint set since the
likes of bluetoothd have dedicated policy around JUST_WORKS method
(e.g. main.conf:JustWorksRepairing).

CVE: CVE-2024-8805
Cc: stable at vger.kernel.org
Fixes: ba15a58b179e ("Bluetooth: Fix SSP acceptor just-works confirmation without MITM")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz at intel.com>
Tested-by: Kiran K <kiran.k at intel.com>
[Nikita: minor fix to resolve a conflict caused by different debug
print macros used around the change: keep BT_DBG() instead of
bt_dev_dbg().]
Signed-off-by: Nikita Zhandarovich <n.zhandarovich at fintech.ru>
---
 net/bluetooth/hci_event.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 58c029958759..546795425119 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4751,19 +4751,16 @@ static void hci_user_confirm_request_evt(struct hci_dev *hdev,
 		goto unlock;
 	}
 
-	/* If no side requires MITM protection; auto-accept */
+	/* If no side requires MITM protection; use JUST_CFM method */
 	if ((!loc_mitm || conn->remote_cap == HCI_IO_NO_INPUT_OUTPUT) &&
 	    (!rem_mitm || conn->io_capability == HCI_IO_NO_INPUT_OUTPUT)) {
 
-		/* If we're not the initiators request authorization to
-		 * proceed from user space (mgmt_user_confirm with
-		 * confirm_hint set to 1). The exception is if neither
-		 * side had MITM or if the local IO capability is
-		 * NoInputNoOutput, in which case we do auto-accept
+		/* If we're not the initiator of request authorization and the
+		 * local IO capability is not NoInputNoOutput, use JUST_WORKS
+		 * method (mgmt_user_confirm with confirm_hint set to 1).
 		 */
 		if (!test_bit(HCI_CONN_AUTH_PEND, &conn->flags) &&
-		    conn->io_capability != HCI_IO_NO_INPUT_OUTPUT &&
-		    (loc_mitm || rem_mitm)) {
+		    conn->io_capability != HCI_IO_NO_INPUT_OUTPUT) {
 			BT_DBG("Confirming auto-accept as acceptor");
 			confirm_hint = 1;
 			goto confirm;
-- 
2.25.1