File HID-accepts-bonded-device-connections-only.patch of Package bluez.27456

From 3cccdbab2324086588df4ccf5f892fb3ce1f1787 Mon Sep 17 00:00:00 2001
From: Alain Michaud <alainm@chromium.org>
Date: Tue Mar 10 02:35:16 2020 +0000
Subject: [PATCH 2/2] HID accepts bonded device connections only.

This change adds a configuration for platforms to choose a more secure
posture for the HID profile.  While some older mice are known to not
support pairing or encryption, some platform may choose a more secure
posture by requiring the device to be bonded  and require the
connection to be encrypted when bonding is required.

Reference:

https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00352.html
---
 profiles/input/device.c   | 24 +++++++++++++++++++++++-
 profiles/input/device.h   |  1 +
 profiles/input/input.conf |  8 ++++++++
 profiles/input/manager.c  | 11 +++++++++++
 4 files changed, 43 insertions(+), 1 deletion(-)

Index: bluez-5.13/profiles/input/device.c
===================================================================
--- bluez-5.13.orig/profiles/input/device.c
+++ bluez-5.13/profiles/input/device.c
@@ -86,12 +86,18 @@ struct input_device {
 };
 
 static int idle_timeout = 0;
+static bool classic_bonded_only = false;
 
 void input_set_idle_timeout(int timeout)
 {
 	idle_timeout = timeout;
 }
 
+void input_set_classic_bonded_only(bool state)
+{
+	classic_bonded_only = state;
+}
+
 static void input_device_enter_reconnect_mode(struct input_device *idev);
 
 static void input_device_free(struct input_device *idev)
@@ -424,8 +430,19 @@ static int hidp_add_connection(struct in
 	if (idev->name)
 		strncpy(req->name, idev->name, sizeof(req->name) - 1);
 
+	/* Make sure the device is bonded if required */
+	if (classic_bonded_only && (!device_is_bonded(idev->device) ||
+				!btd_device_is_connected(idev->device))) {
+		error("Rejected connection from !bonded device %s", dst_addr);
+
+		goto cleanup;
+	}
+
 	/* Encryption is mandatory for keyboards */
-	if (req->subclass & 0x40) {
+	/* Some platforms may choose to require encryption for all devices */
+	/* Note that this only matters for pre 2.1 devices as otherwise the */
+	/* device is encrypted by default by the lower layers */
+	if (classic_bonded_only || req->subclass & 0x40) {
 		if (!bt_io_set(idev->intr_io, &gerr,
 					BT_IO_OPT_SEC_LEVEL, BT_IO_SEC_MEDIUM,
 					BT_IO_OPT_INVALID)) {
@@ -704,6 +721,11 @@ static void input_device_enter_reconnect
 	DBG("path=%s reconnect_mode=%s", idev->path,
 				reconnect_mode_to_string(idev->reconnect_mode));
 
+	/* Make sure the device is bonded if required */
+	if (classic_bonded_only && (!device_is_bonded(idev->device) ||
+				!btd_device_is_connected(idev->device)))
+		return;
+
 	/* Only attempt an auto-reconnect when the device is required to accept
 	 * reconnections from the host. */
 	if (idev->reconnect_mode != RECONNECT_ANY &&
Index: bluez-5.13/profiles/input/device.h
===================================================================
--- bluez-5.13.orig/profiles/input/device.h
+++ bluez-5.13/profiles/input/device.h
@@ -28,6 +28,7 @@ struct input_device;
 struct input_conn;
 
 void input_set_idle_timeout(int timeout);
+void input_set_classic_bonded_only(bool state);
 
 int input_device_register(struct btd_service *service);
 void input_device_unregister(struct btd_service *service);
Index: bluez-5.13/profiles/input/input.conf
===================================================================
--- bluez-5.13.orig/profiles/input/input.conf
+++ bluez-5.13/profiles/input/input.conf
@@ -7,3 +7,11 @@
 # Set idle timeout (in minutes) before the connection will
 # be disconnect (defaults to 0 for no timeout)
 #IdleTimeout=30
+
+# Limit HID connections to bonded devices
+# The HID Profile does not specify that devices must be bonded, however some
+# platforms may want to make sure that input connections only come from bonded
+# device connections. Several older mice have been known for not supporting
+# pairing/encryption.
+# Defaults to false to maximize device compatibility.
+#ClassicBondedOnly=true
Index: bluez-5.13/profiles/input/manager.c
===================================================================
--- bluez-5.13.orig/profiles/input/manager.c
+++ bluez-5.13/profiles/input/manager.c
@@ -97,6 +97,7 @@ static int input_init(void)
 	config = load_config_file(CONFIGDIR "/input.conf");
 	if (config) {
 		int idle_timeout;
+		gboolean uhid_enabled, classic_bonded_only;
 
 		idle_timeout = g_key_file_get_integer(config, "General",
 						"IdleTimeout", &err);
@@ -106,6 +107,16 @@ static int input_init(void)
 		}
 
 		input_set_idle_timeout(idle_timeout * 60);
+
+		classic_bonded_only = g_key_file_get_boolean(config, "General",
+						    "ClassicBondedOnly", &err);
+		if (!err) {
+			DBG("input.conf: ClassicBondedOnly=%s",
+					classic_bonded_only ? "true" : "false");
+			input_set_classic_bonded_only(classic_bonded_only);
+		} else
+			g_clear_error(&err);
+
 	}
 
 	btd_profile_register(&input_profile);