[PATCH 1/4] build: Always define confdir and statedir

[PATCH 1/4] build: Always define confdir and statedir

[Bastien Nocera]

As we will need those paths to lock down on them.
---
 Makefile.am | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index e391d7ae8..2ba25e687 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -28,14 +28,14 @@ AM_CFLAGS = $(MISC_CFLAGS) $(WARNING_CFLAGS) $(UDEV_CFLAGS) $(LIBEBOOK_CFLAGS) \
 				$(LIBEDATASERVER_CFLAGS) $(ell_cflags)
 AM_LDFLAGS = $(MISC_LDFLAGS)
 
+confdir = $(sysconfdir)/bluetooth
+statedir = $(localstatedir)/lib/bluetooth
+
 if DATAFILES
 dbusdir = $(DBUS_CONFDIR)/dbus-1/system.d
 dbus_DATA = src/bluetooth.conf
 
-confdir = $(sysconfdir)/bluetooth
 conf_DATA =
-
-statedir = $(localstatedir)/lib/bluetooth
 state_DATA =
 endif
 
-- 
2.34.1

[PATCH 2/4] systemd: Add PrivateTmp and NoNewPrivileges options

[Bastien Nocera]

From: Craig Andrews <candrews@integralblue.com>

PrivateTmp makes bluetoothd's /tmp and /var/tmp be inside a different
namespace. This is useful to secure access to temporary files of the
process.

NoNewPrivileges ensures that service process and all its children
can never gain new privileges through execve(), lowering the risk of
possible privilege escalations.
---
 src/bluetooth.service.in | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/bluetooth.service.in b/src/bluetooth.service.in
index f9faaa452..7c2f60bb4 100644
--- a/src/bluetooth.service.in
+++ b/src/bluetooth.service.in
@@ -12,8 +12,14 @@ NotifyAccess=main
 #Restart=on-failure
 CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_BIND_SERVICE
 LimitNPROC=1
+
+# Filesystem lockdown
 ProtectHome=true
 ProtectSystem=full
+PrivateTmp=true
+
+# Privilege escalation
+NoNewPrivileges=true
 
 [Install]
 WantedBy=bluetooth.target
-- 
2.34.1

[PATCH 3/4] systemd: Add more filesystem lockdown

[Bastien Nocera]

We can only access the configuration file as read-only and read-write
to the Bluetooth cache directory and sub-directories.
---
 Makefile.am              | 3 +++
 src/bluetooth.service.in | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index 2ba25e687..82125c482 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -622,6 +622,9 @@ MAINTAINERCLEANFILES = Makefile.in \
 
 SED_PROCESS = $(AM_V_GEN)$(MKDIR_P) $(dir $@) && \
 		$(SED) -e 's,@pkglibexecdir\@,$(pkglibexecdir),g' \
+		       -e 's,@libexecdir\@,$(libexecdir),g' \
+		       -e 's,@statedir\@,$(statedir),g' \
+		       -e 's,@confdir\@,$(confdir),g' \
 		< $< > $@
 
 if RUN_RST2MAN
diff --git a/src/bluetooth.service.in b/src/bluetooth.service.in
index 7c2f60bb4..4daedef2a 100644
--- a/src/bluetooth.service.in
+++ b/src/bluetooth.service.in
@@ -17,6 +17,10 @@ LimitNPROC=1
 ProtectHome=true
 ProtectSystem=full
 PrivateTmp=true
+ProtectKernelTunables=true
+ProtectControlGroups=true
+ReadWritePaths=@statedir@
+ReadOnlyPaths=@confdir@
 
 # Privilege escalation
 NoNewPrivileges=true
-- 
2.34.1

[PATCH 4/4] systemd: More lockdown

[Bastien Nocera]

bluetoothd does not need to execute mapped memory, or real-time
access, so block those.
---
 src/bluetooth.service.in | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/bluetooth.service.in b/src/bluetooth.service.in
index 4daedef2a..f18801866 100644
--- a/src/bluetooth.service.in
+++ b/src/bluetooth.service.in
@@ -22,9 +22,15 @@ ProtectControlGroups=true
 ReadWritePaths=@statedir@
 ReadOnlyPaths=@confdir@
 
+# Execute Mappings
+MemoryDenyWriteExecute=true
+
 # Privilege escalation
 NoNewPrivileges=true
 
+# Real-time
+RestrictRealtime=true
+
 [Install]
 WantedBy=bluetooth.target
 Alias=dbus-org.bluez.service
-- 
2.34.1

Re: [PATCH 1/4] build: Always define confdir and statedir

[Bastien Nocera]

Some patches from 2017 to use systemd lockdown. They've been used for 5
years by Fedora and RHEL.

Cheers

On Wed, 2022-01-26 at 12:36 +0100, Bastien Nocera wrote:
> As we will need those paths to lock down on them.
> ---
>  Makefile.am | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/Makefile.am b/Makefile.am
> index e391d7ae8..2ba25e687 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -28,14 +28,14 @@ AM_CFLAGS = $(MISC_CFLAGS) $(WARNING_CFLAGS)
> $(UDEV_CFLAGS) $(LIBEBOOK_CFLAGS) \
>                                 $(LIBEDATASERVER_CFLAGS)
> $(ell_cflags)
>  AM_LDFLAGS = $(MISC_LDFLAGS)
>  
> +confdir = $(sysconfdir)/bluetooth
> +statedir = $(localstatedir)/lib/bluetooth
> +
>  if DATAFILES
>  dbusdir = $(DBUS_CONFDIR)/dbus-1/system.d
>  dbus_DATA = src/bluetooth.conf
>  
> -confdir = $(sysconfdir)/bluetooth
>  conf_DATA =
> -
> -statedir = $(localstatedir)/lib/bluetooth
>  state_DATA =
>  endif
>  

Re: [PATCH 1/4] build: Always define confdir and statedir

[Marcel Holtmann]

Hi Bastien,

> Some patches from 2017 to use systemd lockdown. They've been used for 5
> years by Fedora and RHEL.
> 
>> As we will need those paths to lock down on them.
>> ---
>>  Makefile.am | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>> 
>> diff --git a/Makefile.am b/Makefile.am
>> index e391d7ae8..2ba25e687 100644
>> --- a/Makefile.am
>> +++ b/Makefile.am
>> @@ -28,14 +28,14 @@ AM_CFLAGS = $(MISC_CFLAGS) $(WARNING_CFLAGS)
>> $(UDEV_CFLAGS) $(LIBEBOOK_CFLAGS) \
>>                                 $(LIBEDATASERVER_CFLAGS)
>> $(ell_cflags)
>>  AM_LDFLAGS = $(MISC_LDFLAGS)
>>  
>> +confdir = $(sysconfdir)/bluetooth
>> +statedir = $(localstatedir)/lib/bluetooth
>> +
>>  if DATAFILES
>>  dbusdir = $(DBUS_CONFDIR)/dbus-1/system.d
>>  dbus_DATA = src/bluetooth.conf
>>  
>> -confdir = $(sysconfdir)/bluetooth
>>  conf_DATA =
>> -
>> -statedir = $(localstatedir)/lib/bluetooth
>>  state_DATA =
>>  endif
>>  

seems I missed that one. Can you please be more specific what this change does.

Regards

Marcel

Re: [PATCH 1/4] build: Always define confdir and statedir

[Bastien Nocera]

On Wed, 2022-01-26 at 14:31 +0100, Marcel Holtmann wrote:
> Hi Bastien,
> 
> > Some patches from 2017 to use systemd lockdown. They've been used
> > for 5
> > years by Fedora and RHEL.
> > 
> > > As we will need those paths to lock down on them.
> > > ---
> > >  Makefile.am | 6 +++---
> > >  1 file changed, 3 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/Makefile.am b/Makefile.am
> > > index e391d7ae8..2ba25e687 100644
> > > --- a/Makefile.am
> > > +++ b/Makefile.am
> > > @@ -28,14 +28,14 @@ AM_CFLAGS = $(MISC_CFLAGS) $(WARNING_CFLAGS)
> > > $(UDEV_CFLAGS) $(LIBEBOOK_CFLAGS) \
> > >                                 $(LIBEDATASERVER_CFLAGS)
> > > $(ell_cflags)
> > >  AM_LDFLAGS = $(MISC_LDFLAGS)
> > >  
> > > +confdir = $(sysconfdir)/bluetooth
> > > +statedir = $(localstatedir)/lib/bluetooth
> > > +
> > >  if DATAFILES
> > >  dbusdir = $(DBUS_CONFDIR)/dbus-1/system.d
> > >  dbus_DATA = src/bluetooth.conf
> > >  
> > > -confdir = $(sysconfdir)/bluetooth
> > >  conf_DATA =
> > > -
> > > -statedir = $(localstatedir)/lib/bluetooth
> > >  state_DATA =
> > >  endif
> > >  
> 
> seems I missed that one. Can you please be more specific what this
> change does.

This change specifically? Check the next patches in the series, and
you'll see pretty quickly.

For the rest of the patchset, check this man page for details on each
of the directives:
https://www.freedesktop.org/software/systemd/man/systemd.exec.html#Security

There's a fair amount of other directives we could use on top of those
ones, but we can add them iteratively (and it makes bisecting easier,
in case we forget about a particular use case).

Cheers

Re: [PATCH 1/4] build: Always define confdir and statedir

[Bastien Nocera]

On Wed, 2022-01-26 at 14:45 +0100, Bastien Nocera wrote:
> This change specifically? Check the next patches in the series, and
> you'll see pretty quickly.
> 
> For the rest of the patchset, check this man page for details on each
> of the directives:
> https://www.freedesktop.org/software/systemd/man/systemd.exec.html#Security
> 
> There's a fair amount of other directives we could use on top of
> those
> ones, but we can add them iteratively (and it makes bisecting easier,
> in case we forget about a particular use case).

Did you have any more questions about this patchset?

Re: [PATCH 1/4] build: Always define confdir and statedir

[Luiz Augusto von Dentz]

Hi Bastien,

On Wed, Feb 2, 2022 at 5:55 AM Bastien Nocera <hadess@hadess.net> wrote:
>
> On Wed, 2022-01-26 at 14:45 +0100, Bastien Nocera wrote:
> > This change specifically? Check the next patches in the series, and
> > you'll see pretty quickly.
> >
> > For the rest of the patchset, check this man page for details on each
> > of the directives:
> > https://www.freedesktop.org/software/systemd/man/systemd.exec.html#Security
> >
> > There's a fair amount of other directives we could use on top of
> > those
> > ones, but we can add them iteratively (and it makes bisecting easier,
> > in case we forget about a particular use case).
>
> Did you have any more questions about this patchset?

Looks like we have some problems with these changes:

https://github.com/bluez/bluez/issues/329

-- 
Luiz Augusto von Dentz

RE: [1/4] build: Always define confdir and statedir

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 998 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=608628

---Test result---

Test Summary:
CheckPatch                    PASS      5.68 seconds
GitLint                       PASS      3.84 seconds
Prep - Setup ELL              PASS      41.84 seconds
Build - Prep                  PASS      0.71 seconds
Build - Configure             PASS      8.38 seconds
Build - Make                  PASS      1292.67 seconds
Make Check                    PASS      11.33 seconds
Make Check w/Valgrind         PASS      448.95 seconds
Make Distcheck                PASS      231.67 seconds
Build w/ext ELL - Configure   PASS      8.74 seconds
Build w/ext ELL - Make        PASS      1305.94 seconds
Incremental Build with patchesPASS      5303.63 seconds



---
Regards,
Linux Bluetooth

Re: [1/4] build: Always define confdir and statedir

[Luiz Augusto von Dentz]

Hi Bastien,

On Wed, Jan 26, 2022 at 1:28 PM <bluez.test.bot@gmail.com> wrote:
>
> This is automated email and please do not reply to this email!
>
> Dear submitter,
>
> Thank you for submitting the patches to the linux bluetooth mailing list.
> This is a CI test results with your patch series:
> PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=608628
>
> ---Test result---
>
> Test Summary:
> CheckPatch                    PASS      5.68 seconds
> GitLint                       PASS      3.84 seconds
> Prep - Setup ELL              PASS      41.84 seconds
> Build - Prep                  PASS      0.71 seconds
> Build - Configure             PASS      8.38 seconds
> Build - Make                  PASS      1292.67 seconds
> Make Check                    PASS      11.33 seconds
> Make Check w/Valgrind         PASS      448.95 seconds
> Make Distcheck                PASS      231.67 seconds
> Build w/ext ELL - Configure   PASS      8.74 seconds
> Build w/ext ELL - Make        PASS      1305.94 seconds
> Incremental Build with patchesPASS      5303.63 seconds
>
>
>
> ---
> Regards,
> Linux Bluetooth

Applied, thanks.

-- 
Luiz Augusto von Dentz

[PATCH 1/4] build: Always define confdir and statedir

[Bastien Nocera]

As we will need those paths to lock down on them.
---
 Makefile.am | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 555f301ca..1c38d94e5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -30,14 +30,14 @@ include_HEADERS =
 AM_CFLAGS = $(WARNING_CFLAGS) $(MISC_CFLAGS)
 AM_LDFLAGS = $(MISC_LDFLAGS)
 
+confdir = $(sysconfdir)/bluetooth
+statedir = $(localstatedir)/lib/bluetooth
+
 if DATAFILES
 dbusdir = @DBUS_CONFDIR@/dbus-1/system.d
 dbus_DATA = src/bluetooth.conf
 
-confdir = $(sysconfdir)/bluetooth
 conf_DATA =
-
-statedir = $(localstatedir)/lib/bluetooth
 state_DATA =
 endif
 
-- 
2.14.1

[PATCH 3/4] systemd: Add more filesystem lockdown

[Bastien Nocera]

We can only access the configuration file as read-only and read-write
to the Bluetooth cache directory and sub-directories.
---
 Makefile.am              | 2 ++
 src/bluetooth.service.in | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index 1c38d94e5..13ccf9079 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -478,6 +478,8 @@ MAINTAINERCLEANFILES = Makefile.in \
 
 SED_PROCESS = $(AM_V_GEN)$(MKDIR_P) $(dir $@) && \
 		$(SED) -e 's,@libexecdir\@,$(libexecdir),g' \
+		       -e 's,@statedir\@,$(statedir),g' \
+		       -e 's,@confdir\@,$(confdir),g' \
 		< $< > $@
 
 %.service: %.service.in Makefile
diff --git a/src/bluetooth.service.in b/src/bluetooth.service.in
index a6f3030f9..7e55b5043 100644
--- a/src/bluetooth.service.in
+++ b/src/bluetooth.service.in
@@ -17,6 +17,10 @@ LimitNPROC=1
 ProtectHome=true
 ProtectSystem=full
 PrivateTmp=true
+ProtectKernelTunables=true
+ProtectControlGroups=true
+ReadWritePaths=@statedir@
+ReadOnlyPaths=@confdir@
 
 # Privilege escalation
 NoNewPrivileges=true
-- 
2.14.1