bug#40044: [PATCH] gnu: BlueZ: Fix CVE-2020-0556.

[Leo Famulari <leo@famulari.name>]

On Thu, Mar 12, 2020 at 03:28:59PM -0400, Leo Famulari wrote:
> * gnu/packages/patches/bluez-CVE-2020-0556.patch: New file.
> * gnu/local.mk (dist_patch_DATA): Add it.
> * gnu/packages/linux.scm (bluez)[replacement]: New field.
> (bluez/fixed): New variable.

Pushed as 364a1374ad5e04a91cdc29203f0c8073eede72d4. Thanks nckx for
testing!

> ---
>  gnu/local.mk                                  |   1 +
>  gnu/packages/linux.scm                        |   9 +
>  .../patches/bluez-CVE-2020-0556.patch         | 180 ++++++++++++++++++
>  3 files changed, 190 insertions(+)
>  create mode 100644 gnu/packages/patches/bluez-CVE-2020-0556.patch
> 
> diff --git a/gnu/local.mk b/gnu/local.mk
> index 99baddea92..8e312e24e7 100644
> --- a/gnu/local.mk
> +++ b/gnu/local.mk
> @@ -763,6 +763,7 @@ dist_patch_DATA =						\
>    %D%/packages/patches/binutils-loongson-workaround.patch	\
>    %D%/packages/patches/blender-2.79-newer-ffmpeg.patch		\
>    %D%/packages/patches/blender-2.79-python-3.7-fix.patch	\
> +  %D%/packages/patches/bluez-CVE-2020-0556.patch		\
>    %D%/packages/patches/byobu-writable-status.patch		\
>    %D%/packages/patches/calibre-no-updates-dialog.patch		\
>    %D%/packages/patches/calibre-remove-test-bs4.patch		\
> diff --git a/gnu/packages/linux.scm b/gnu/packages/linux.scm
> index 01986222e8..0e84a1750e 100644
> --- a/gnu/packages/linux.scm
> +++ b/gnu/packages/linux.scm
> @@ -3994,6 +3994,7 @@ Bluetooth audio output devices like headphones or loudspeakers.")
>  (define-public bluez
>    (package
>      (name "bluez")
> +    (replacement bluez/fixed)
>      (version "5.52")
>      (source (origin
>                (method url-fetch)
> @@ -4059,6 +4060,14 @@ Bluetooth audio output devices like headphones or loudspeakers.")
>  is flexible, efficient and uses a modular implementation.")
>      (license license:gpl2+)))
>  
> +(define bluez/fixed
> +  (package
> +    (inherit bluez)
> +    (source (origin
> +              (inherit (package-source bluez))
> +              (patches (append (origin-patches (package-source bluez))
> +                               (search-patches "bluez-CVE-2020-0556.patch")))))))
> +
>  (define-public fuse-exfat
>    (package
>      (name "fuse-exfat")
> diff --git a/gnu/packages/patches/bluez-CVE-2020-0556.patch b/gnu/packages/patches/bluez-CVE-2020-0556.patch
> new file mode 100644
> index 0000000000..7c34459a3a
> --- /dev/null
> +++ b/gnu/packages/patches/bluez-CVE-2020-0556.patch
> @@ -0,0 +1,180 @@
> +Fix CVE-2020-0556:
> +
> +https://lore.kernel.org/linux-bluetooth/20200310023516.209146-1-alainm@chromium.org/
> +https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00352.html
> +http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-0556
> +
> +Patches copied from upstream source repository:
> +
> +https://git.kernel.org/pub/scm/bluetooth/bluez.git/commit/?id=3cccdbab2324086588df4ccf5f892fb3ce1f1787
> +https://git.kernel.org/pub/scm/bluetooth/bluez.git/commit/?id=8cdbd3b09f29da29374e2f83369df24228da0ad1
> +
> +From 3cccdbab2324086588df4ccf5f892fb3ce1f1787 Mon Sep 17 00:00:00 2001
> +From: Alain Michaud <alainm@chromium.org>
> +Date: Tue, 10 Mar 2020 02:35:18 +0000
> +Subject: [PATCH] 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   | 23 ++++++++++++++++++++++-
> + profiles/input/device.h   |  1 +
> + profiles/input/input.conf |  8 ++++++++
> + profiles/input/manager.c  | 13 ++++++++++++-
> + 4 files changed, 43 insertions(+), 2 deletions(-)
> +
> +diff --git a/profiles/input/device.c b/profiles/input/device.c
> +index 2cb3811c8..d89da2d7c 100644
> +--- a/profiles/input/device.c
> ++++ b/profiles/input/device.c
> +@@ -92,6 +92,7 @@ struct input_device {
> + 
> + static int idle_timeout = 0;
> + static bool uhid_enabled = false;
> ++static bool classic_bonded_only = false;
> + 
> + void input_set_idle_timeout(int timeout)
> + {
> +@@ -103,6 +104,11 @@ void input_enable_userspace_hid(bool state)
> + 	uhid_enabled = state;
> + }
> + 
> ++void input_set_classic_bonded_only(bool state)
> ++{
> ++	classic_bonded_only = state;
> ++}
> ++
> + static void input_device_enter_reconnect_mode(struct input_device *idev);
> + static int connection_disconnect(struct input_device *idev, uint32_t flags);
> + 
> +@@ -970,8 +976,18 @@ static int hidp_add_connection(struct input_device *idev)
> + 	if (device_name_known(idev->device))
> + 		device_get_name(idev->device, req->name, sizeof(req->name));
> + 
> ++	/* Make sure the device is bonded if required */
> ++	if (classic_bonded_only && !device_is_bonded(idev->device,
> ++				btd_device_get_bdaddr_type(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)) {
> +@@ -1203,6 +1219,11 @@ static void input_device_enter_reconnect_mode(struct input_device *idev)
> + 	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_get_bdaddr_type(idev->device)))
> ++		return;
> ++
> + 	/* Only attempt an auto-reconnect when the device is required to
> + 	 * accept reconnections from the host.
> + 	 */
> +diff --git a/profiles/input/device.h b/profiles/input/device.h
> +index 51a9aee18..3044db673 100644
> +--- a/profiles/input/device.h
> ++++ b/profiles/input/device.h
> +@@ -29,6 +29,7 @@ struct input_conn;
> + 
> + void input_set_idle_timeout(int timeout);
> + void input_enable_userspace_hid(bool state);
> ++void input_set_classic_bonded_only(bool state);
> + 
> + int input_device_register(struct btd_service *service);
> + void input_device_unregister(struct btd_service *service);
> +diff --git a/profiles/input/input.conf b/profiles/input/input.conf
> +index 3e1d65aae..166aff4a4 100644
> +--- a/profiles/input/input.conf
> ++++ b/profiles/input/input.conf
> +@@ -11,3 +11,11 @@
> + # Enable HID protocol handling in userspace input profile
> + # Defaults to false (HIDP handled in HIDP kernel module)
> + #UserspaceHID=true
> ++
> ++# 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
> +diff --git a/profiles/input/manager.c b/profiles/input/manager.c
> +index 1d31b0652..5cd27b839 100644
> +--- a/profiles/input/manager.c
> ++++ b/profiles/input/manager.c
> +@@ -96,7 +96,7 @@ static int input_init(void)
> + 	config = load_config_file(CONFIGDIR "/input.conf");
> + 	if (config) {
> + 		int idle_timeout;
> +-		gboolean uhid_enabled;
> ++		gboolean uhid_enabled, classic_bonded_only;
> + 
> + 		idle_timeout = g_key_file_get_integer(config, "General",
> + 							"IdleTimeout", &err);
> +@@ -114,6 +114,17 @@ static int input_init(void)
> + 			input_enable_userspace_hid(uhid_enabled);
> + 		} else
> + 			g_clear_error(&err);
> ++
> ++		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);
> +-- 
> +2.25.1
> +
> +From 8cdbd3b09f29da29374e2f83369df24228da0ad1 Mon Sep 17 00:00:00 2001
> +From: Alain Michaud <alainm@chromium.org>
> +Date: Tue, 10 Mar 2020 02:35:16 +0000
> +Subject: [PATCH] HOGP must only accept data from bonded devices.
> +
> +HOGP 1.0 Section 6.1 establishes that the HOGP must require bonding.
> +
> +Reference:
> +https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00352.htm
> +---
> + profiles/input/hog.c | 4 ++++
> + 1 file changed, 4 insertions(+)
> +
> +diff --git a/profiles/input/hog.c b/profiles/input/hog.c
> +index 83c017dcb..dfac68921 100644
> +--- a/profiles/input/hog.c
> ++++ b/profiles/input/hog.c
> +@@ -186,6 +186,10 @@ static int hog_accept(struct btd_service *service)
> + 			return -EINVAL;
> + 	}
> + 
> ++	/* HOGP 1.0 Section 6.1 requires bonding */
> ++	if (!device_is_bonded(device, btd_device_get_bdaddr_type(device)))
> ++		return -ECONNREFUSED;
> ++
> + 	/* TODO: Replace GAttrib with bt_gatt_client */
> + 	bt_hog_attach(dev->hog, attrib);
> + 
> +-- 
> +2.25.1
> +
> -- 
> 2.25.1
>