Re: [PATCH v1] Adding Sepolicy rules to allow bluetoothctl and dbus-daemon to access unix stream sockets.

Chris PeBenito <[email protected]> Tue, 14 May 2024 16:12:16 -0400
Newsgroups org.kernel.vger.selinux-refpolicy
Message-ID <[email protected]>
On 5/14/2024 3:21 AM, Naga Bhavani Akella wrote:
> Required for using acquire-notify, acquire-write options (Gatt Client)
> and Sending notifications (Gatt Server)
> 
> Below are the avc denials that are fixed with this patch -
> 
> 1. audit: type=1400 audit(1651238006.276:496):
> avc:  denied  { read write } for  pid=2165 comm="bluetoothd"
> path="socket:[43207]" dev="sockfs" ino=43207
> scontext=system_u:system_r:bluetooth_t:s0-s15:c0.c1023
> tcontext=system_u:system_r:initrc_t:s0-s15:c0.c1023
> tclass=unix_stream_socket permissive=1
> 2. audit: type=1400 audit(1651238006.276:497):
> avc:  denied  { getattr } for  pid=2165 comm="bluetoothd"
> path="socket:[43207]" dev="sockfs" ino=43207
> scontext=system_u:system_r:bluetooth_t:s0-s15:c0.c1023
> tcontext=system_u:system_r:initrc_t:s0-s15:c0.c1023
> tclass=unix_stream_socket permissive=1
> 3. audit: type=1400 audit(1651238006.272:495):
> avc:  denied  { read write } for  pid=689 comm="dbus-daemon"
> path="socket:[43207]" dev="sockfs" ino=43207
> scontext=system_u:system_r:system_dbusd_t:s0-s15:c0.c1023
> tcontext=system_u:system_r:initrc_t:s0-s15:c0.c1023
> tclass=unix_stream_socket permissive=1
> 4. audit: type=1400 audit(315966559.395:444):
> avc:  denied  { use } for  pid=710 comm="dbus-daemon"
> path="socket:[13196]" dev="sockfs" ino=13196
> scontext=system_u:system_r:system_dbusd_t:s0-s15:c0.c1023
> tcontext=system_u:system_r:bluetooth_t:s0-s15:c0.c1023
> tclass=fd permissive=0
> 5. audit: type=1400 audit(315999854.939:523):
> avc:  denied  { read write } for  pid=812 comm="dbus-daemon"
> path="socket:[99469]" dev="sockfs" ino=99469
> scontext=system_u:system_r:system_dbusd_t:s0-s15:c0.c1023
> tcontext=system_u:system_r:bluetooth_t:s0-s15:c0.c1023
> tclass=bluetooth_socket permissive=1
> 
> Signed-off-by: Naga Bhavani Akella <[email protected]>
> ---
>   policy/modules/services/bluetooth.fc | 1 +
>   policy/modules/services/bluetooth.if | 3 +++
>   2 files changed, 4 insertions(+)
> 
> diff --git a/policy/modules/services/bluetooth.fc b/policy/modules/services/bluetooth.fc
> index e167e93f7..03f42fc8b 100644
> --- a/policy/modules/services/bluetooth.fc
> +++ b/policy/modules/services/bluetooth.fc
> @@ -7,6 +7,7 @@
>   
>   /usr/bin/blue.*pin	--	gen_context(system_u:object_r:bluetooth_helper_exec_t,s0)
>   /usr/bin/bluetoothd	--	gen_context(system_u:object_r:bluetooth_exec_t,s0)
> +/usr/bin/bluetoothctl	--	gen_context(system_u:object_r:bluetooth_exec_t,s0)
>   /usr/bin/dund	--	gen_context(system_u:object_r:bluetooth_exec_t,s0)
>   /usr/bin/hciattach	--	gen_context(system_u:object_r:bluetooth_exec_t,s0)
>   /usr/bin/hcid	--	gen_context(system_u:object_r:bluetooth_exec_t,s0)
> diff --git a/policy/modules/services/bluetooth.if b/policy/modules/services/bluetooth.if
> index c7e1c3f14..c869eed71 100644
> --- a/policy/modules/services/bluetooth.if
> +++ b/policy/modules/services/bluetooth.if
> @@ -82,6 +82,9 @@ interface(`bluetooth_stream_connect',`
>   
>   	files_search_runtime($1)
>   	allow $1 bluetooth_t:socket rw_socket_perms;
> +	allow $1 bluetooth_t:bluetooth_socket rw_socket_perms;
> +	allow $1 bluetooth_t:unix_stream_socket { accept connectto listen rw_socket_perms };
> +	allow $1 bluetooth_t:fd use;
>   	stream_connect_pattern($1, bluetooth_runtime_t, bluetooth_runtime_t, bluetooth_t)
>   ')

I have two main concerns:

1. is the added access in this interface required for all users that 
connect to bluetoothd over a unix domain socket?

2. does bluetoothctl really need all the access of the bluetooth_t 
domain?  It may only need a small permission set, like udev and udevctl.


-- 
Chris PeBenito