<s>
Smack	B-Application
(	O
full	O
name	O
:	O
Simplified	B-Application
Mandatory	I-Application
Access	I-Application
Control	I-Application
Kernel	I-Application
)	O
is	O
a	O
Linux	B-Operating_System
kernel	I-Operating_System
security	B-Application
module	I-Application
that	O
protects	O
data	O
and	O
process	O
interaction	O
from	O
malicious	O
manipulation	O
using	O
a	O
set	O
of	O
custom	O
mandatory	O
access	O
control	O
(	O
MAC	O
)	O
rules	O
,	O
with	O
simplicity	O
as	O
its	O
main	O
design	O
goal	O
.	O
</s>
<s>
It	O
has	O
been	O
officially	O
merged	O
since	O
the	O
Linux	O
2.6.25	O
release	O
,	O
it	O
was	O
the	O
main	O
access	O
control	O
mechanism	O
for	O
the	O
MeeGo	B-Operating_System
mobile	O
Operating	O
System	O
.	O
</s>
<s>
It	O
is	O
also	O
used	O
to	O
sandbox	O
HTML5	O
web	O
applications	O
in	O
the	O
Tizen	B-Application
architecture	O
,	O
in	O
the	O
commercial	O
Wind	O
River	O
Linux	B-Operating_System
solutions	O
for	O
embedded	O
device	O
development	O
,	O
in	O
Philips	O
Digital	O
TV	O
products.	O
,	O
and	O
in	O
Intel	O
's	O
Ostro	O
OS	O
for	O
IoT	O
devices	O
.	O
</s>
<s>
Since	O
2016	O
,	O
Smack	B-Application
is	O
required	O
in	O
all	O
Automotive	B-Application
Grade	I-Application
Linux	I-Application
(	O
AGL	O
)	O
implementations	O
where	O
it	O
provides	O
in	O
association	O
with	O
other	O
Linux	B-Operating_System
facilities	O
the	O
base	O
for	O
the	O
AGL	O
security	O
framework	O
.	O
</s>
<s>
Smack	B-Application
consists	O
of	O
three	O
components	O
:	O
</s>
<s>
A	O
kernel	B-Operating_System
module	O
that	O
is	O
implemented	O
as	O
a	O
Linux	B-Application
Security	I-Application
Module	I-Application
.	O
</s>
<s>
It	O
works	O
best	O
with	O
file	B-Application
systems	I-Application
that	O
support	O
extended	B-Application
attributes	I-Application
.	O
</s>
<s>
A	O
startup	O
script	O
that	O
ensures	O
that	O
device	O
files	O
have	O
the	O
correct	O
Smack	B-Application
attributes	O
and	O
loads	O
the	O
Smack	B-Application
configuration	O
.	O
</s>
<s>
A	O
set	O
of	O
patches	O
to	O
the	O
GNU	B-Application
Core	I-Application
Utilities	I-Application
package	O
to	O
make	O
it	O
aware	O
of	O
Smack	B-Application
extended	B-Application
file	I-Application
attributes	I-Application
.	O
</s>
<s>
A	O
set	O
of	O
similar	O
patches	O
to	O
Busybox	B-Application
were	O
also	O
created	O
.	O
</s>
<s>
SMACK	B-Application
does	O
not	O
require	O
user-space	O
support	O
.	O
</s>
<s>
Smack	B-Application
has	O
been	O
criticized	O
for	O
being	O
written	O
as	O
a	O
new	O
LSM	O
module	O
instead	O
of	O
an	O
SELinux	B-Application
security	O
policy	O
which	O
can	O
provide	O
equivalent	O
functionality	O
.	O
</s>
<s>
Such	O
SELinux	B-Application
policies	O
have	O
been	O
proposed	O
,	O
but	O
none	O
had	O
been	O
demonstrated	O
.	O
</s>
<s>
Smack	B-Application
's	O
author	O
replied	O
that	O
it	O
would	O
not	O
be	O
practical	O
due	O
to	O
SELinux	B-Application
's	O
complicated	O
configuration	O
syntax	O
and	O
the	O
philosophical	O
difference	O
between	O
Smack	B-Application
and	O
SELinux	B-Application
designs	O
.	O
</s>
