On 5/15/2024 3:29 AM, Naga Bhavani Akella wrote:
Hi Chris PeBenito,
Thank you for your comments.
On 5/15/2024 1:42 AM, Chris PeBenito wrote:
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 <quic_nakella@xxxxxxxxxxx>
---
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?
As per my understanding any user who wants to use bluetooth over unix domain has to make dbus calls to bluetoothd. So I feel its required. For example- bluetooth_stream_connect is currently being used by pulseaudio_t and obex_t as well, these services also use dbus methods.
Please let us know your opinion on this or better way to fix these AVC denials.
In that case, then a new interface with a more abstract name would be
warranted.
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.
By default bluetoothctl is running in initrc_t domain so added bluetooth_exec_t domain to bluetoothctl. bluetoothctl is command line tool to access whole bluetooth functionality like pair/unpair/connect/disconnect etc. There are other tools like hciattach, rfcomm which are using same domain bluetooth_exec_t.
Yes, the point is that we probably need a bluetoothctl_t domain so the
configuration can be done only via the bluetoothctl process, not just
any initrc_t process. The existing bluetooth_helper_t domain may
possibly be renamed/retrofitted for this purpose.
--
Chris PeBenito
