Add the ability to control mounting and unmounting
The basic form of the rules are.
[audit] [deny] mount [conds]* [device] [ -> [conds] path],
[audit] [deny] remount [conds]* [path],
[audit] [deny] umount [conds]* [path],
[audit] [deny] pivotroot [oldroot=<value>] <path> -> <profile>
remount is just a short cut for mount options=remount
where [conds] can be
fstype=<expr>
options=<expr>
conds follow the extended conditional syntax of allowing either:
* a single value after the equals, which has the same character range as
regular IDS (ie most anything but it can't be terminated with a , (comma)
and if spaces or other characters are needed it can be quoted
eg.
options=foo
options = foo
options="foo bar"
* a list of values after the equals, the list of values is enclosed within
parenthesis () and its has a slightly reduced character set but again
elements can be quoted.
the separation between elements is whitespace and commas.
eg.
options=(foo bar)
options=(foo, bar)
options=(foo , bar)
options=(foo,bar)
The rules are flexible and follow a similar pattern as network, capability,
etc.
mount, # allow all mounts, but not umount or pivotroot
mount fstype=procfs, # allow mounting procfs anywhere
mount options=(bind, ro) /foo -> /bar, # readonly bind mount
mount /dev/sda -> /mnt,
mount /dev/sd** -> /mnt/**,
mount fstype=overlayfs options=(rw,upperdir=/tmp/upper/,lowerdir=/) overlay -> /mnt/
umount,
umount /m*,
Currently variables and regexs are are supported on the device and mount
point. ie.
mount <devince> -> <mount point>,
Regexes are supported in fstype and options. The options have a further
caveat that regexs only work if the option is fs specific option.
eg. options=(upperdir=/tmp/*,lowerdir=/)
regex's will not currently work against the standard options like ro, rw
nosuid
Conditionals (fstype) can only be applied to the device (source) at this
time and will be disregarded in situations where the mount is manipulating
an existing mount (bind, remount).
Options can be specified multiple times
mount option=rw option=(nosuid,upperdir=/foo),
and will be combined together into a single set of values
The ordering of the standard mount options (rw,ro, ...) does not matter
but the ordering of fs specific options does.
Specifying that the value of a particular option does not matter can be
acheived by providing both the positive and negative forms of and option
option=(rw,ro) options=(suid,nosuid)
For the fs specific options specifying that a particular value does not
matter is achieve using a regex with alternations.
Improvements to the syntax and order restrictions are planned for the
future.
Signed-off-by: John Johansen <john.johansen@canonical.com>
value_list can be reused by conditionals and list values, so pull it out
and abstract it some more.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
Add the optional 'file' keyword to the language/grammer. The main reason
for doing this is to support false token injection. Which is needed
to move towards the parser being broken out into an api that can be
used to parse individual rule types, separate from parsing the whole file.
Since we are adding the token to the grammar expose it to userspace with
the 'file' keyword. While not needed it helps bring consistency, as all
the other rule types start with a keyword (capability, network, rlimit, ...).
Also allow the bare keyword to be used to represent allowing all file
operations, just as with network and capability. Domain transitions are
defaulted to ix. Thus
file,
is equivalent to
/** rwlkmix,
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
The ability to set capabilities from a profile has been removed from the
kernel for several releases. Remove it from the parser as well.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
jj@ortho:~/apparmor/aa-test/parser$ guilt header
Convert FLAGS_MODE start condition to a generic list of values start cond
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
Change how we handle the parsing of the hat and profile keywords this allows
us to get rid of the SUB_NAME2 start condition because the the whitespace
that is allowed by these rules are now consumed by matching the keyword
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
There is a lot of duplication of code calling processqunquoted and
processquoted. Move all this code to use the new processid fn.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
This is a rather large rearrangement of how a subset of the parser global
variables are defined. Right now, there are unit tests built without
linking against parser_main.c. As a result, none of the globals defined in
parser_main.c could be used in the code that is built for unit tests
(misc, regex, symtab, variable). To get a clean build, either stubs needed
to be added to "#ifdef UNIT_TEST" blocks in each .c file, or we had to
depend on link-time optimizations that would throw out the unused routines.
First, this is a problem because all the compile-time warnings had to be
explicitly silenced, so reviewing the build logs becomes difficult on
failures, and we can potentially (in really unlucky situations) test
something that isn't actually part of the "real" parser.
Second, not all compilers will allow this kind of linking (e.g. mips gcc),
and the missing symbols at link time will fail the entire build even though
they're technically not needed.
To solve all of this, I've moved all of the global variables used in lex,
yacc, and main to parser_common.c, and adjusted the .h files. On top of
this, I made sure to fully link the tst builds so all symbols are resolved
(including aare lib) and removedonly tst build-log silencing (for now,
deferring to another future patchset to consolidate the build silencing).
Signed-off-by: Kees Cook <kees.cook@canonical.com>
about an actual bug in the parser; namely that when handling strings
encapsulated in quotes, that our handling of octals is busted. It
fixes this by fixing the case entries so that 3 digit octals will
get parsed correctly, rather than dropped.
It also adds a bunch of unit tests for the processquoted() function.
Older versions of the apparmor kernel patches didn't handle receiving
network tables of a larger size than expected.
Allow the parser to detect the kernel version and override the AF_MAX
value for those kernels.
This also replaces the hack using a hardcoded limit of 36 for kernels
missing the features flag.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Currently apparmor provides the unsafe keyword to indicate an xtransition
is not scrubbing its environment variables. This can be used to be
explicit about which transition are unsafe instead of relying on people
remembering which of px Px is safe or unsafe.
Add the orthogonal keyword safe to allow specifying a transition is
safe.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Alias was broken because it when an alias was made the old path was completely
removed and there was no way to specify it. Update it so aliases just add
an new duplicate rule instead.
thing again. Fix to use the kernel's definition of AF_MAX in
linux/socket.h if it's larger than glibc's AF_MAX definition in
sys/socket.h and add a wrapper function so that we don't have include
af_names.h everywhere.
Also, fix memory leaks around the handling of network entries of
policies.
- fix "Namespcae" tyop
- get rid of sub_name and default_deny from the main profile struct as
they haven't been used for a long time; also eliminates their output
from the debugging output.
- emit dumped parsing structure with only one -d, users were confuzzled
and it was not documented that you needed to use -dd to get it to
output anything if DEBUG wasn't set when compiling.
key words. Deny is also used to subtract permissions from the
profiles permission set.
the audit key word can be prepended to any file, network, or capability
rule, to force a selective audit when that rule is matched. Audit
permissions accumulate just like standard permissions.
eg.
audit /bin/foo rw,
will force an audit message when the file /bin/foo is opened for
read or write.
audit /etc/shadow w,
/etc/shadow r,
will force an audit message when /etc/shadow is opened for writing.
The audit message is per permission bit so only opening the file
for read access will not, force an audit message.
audit can also be used in block form instead of prepending audit
to every rule.
audit {
/bin/foo rw,
/etc/shadow w,
}
/etc/shadow r, # don't audit r access to /etc/shadow
the deny key word can be prepended to file, network and capability
rules, to result in a denial of permissions when matching that rule.
The deny rule specifically does 3 things
- it gives AppArmor the ability to remember what has been denied
so that the tools don't prompt for what has been denied in
previous profiling sessions.
- it subtracts globally from the allowed permissions. Deny permissions
accumulate in the the deny set just as allow permissions accumulate
then, the deny set is subtracted from the allow set.
- it quiets known rejects. The default audit behavior of deny rules
is to quiet known rejects so that audit logs are not flooded
with already known rejects. To have known rejects logged prepend
the audit keyword to the deny rule. Deny rules do not have a
block form.
eg.
deny /foo/bar rw,
audit deny /etc/shadow w,
audit {
deny owner /blah w,
deny other /foo w,
deny /etc/shadow w,
}
