Expression simplification can get into an infinite loop due to eps
pairs hiding behind and alternation that can't be caught by
normalize_eps() (which exists in the first place to stop a similar
loop).
The loop in question happens in AltNode::normalize when a subtree has
the following structure.
1. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
2. if (normalize_eps(dir)) results in
alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
3. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
alt alt
/\ /\
/ \ / \
/ \ / \
eps eps eps eps
4. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps eps
5. if (normalize_eps(dir)) results in
alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps eps
6. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
back to beginning of cycle
Fix this by detecting the creation of an eps_pair in rotate_node(),
that pair can be immediately eliminated by simplifying the tree in that
step.
In the above cycle the pair creation is caught at step 3 resulting
in
3. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
4. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps eps
which gets reduced to
alt
/\
/ \
/ \
eps eps
breaking the normalization loop. The degenerate alt node will be caught
in turn when its parent is dealt with.
This needs to be backported to all releases
Closes: https://gitlab.com/apparmor/apparmor/-/issues/398
Fixes: 846cee506 ("Split out parsing and expression trees from regexp.y")
Reported-by: Christian Boltz <apparmor@cboltz.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Closes#398
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1252
Approved-by: Georgia Garcia <georgia.garcia@canonical.com>
Merged-by: John Johansen <john@jjmx.net>
Expression simplification can get into an infinite loop due to eps
pairs hiding behind and alternation that can't be caught by
normalize_eps() (which exists in the first place to stop a similar
loop).
The loop in question happens in AltNode::normalize when a subtree has
the following structure.
1. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
2. if (normalize_eps(dir)) results in
alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
3. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
alt alt
/\ /\
/ \ / \
/ \ / \
eps eps eps eps
4. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps eps
5. if (normalize_eps(dir)) results in
alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps eps
6. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
back to beginning of cycle
Fix this by detecting the creation of an eps_pair in rotate_node(),
that pair can be immediately eliminated by simplifying the tree in that
step.
In the above cycle the pair creation is caught at step 3 resulting
in
3. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
alt eps
/\
/ \
/ \
eps eps
4. elseif (child[dir]->is_type(ALT_NODE)) rotate_node too
alt
/\
/ \
/ \
eps alt
/\
/ \
/ \
eps eps
whch gets reduces to
alt
/\
/ \
/ \
eps eps
breaking the normalization loop. The degenerate alt node will be caught
in turn when its parent is dealt with.
This needs to be backported to all releases
Closes: https://gitlab.com/apparmor/apparmor/-/issues/398
Fixes: 846cee506 ("Split out parsing and expression trees from regexp.y")
Reported-by: Christian Boltz <apparmor@cboltz.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Adding mediation classes in unconfined profiles caused nested profiles
to be mediated, inside a container for example.
As a first step, skip the addition of mediation classes into the dfa.
The creation of unprivileged user namespaces is an exception, where we
always want to mediate it.
Fixes: https://bugs.launchpad.net/apparmor/+bug/2067900
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
technically a # leading a value in an assignment expression is allowed,
however people are also using it to a comment at the end of a line.
ie.
```
@{var1}=value1 # comment about this value or for a given system
```
this unsurprisingly leads to odd/unexpected behavior when the variable
is used.
```
allow rw /@{var1},
```
expands into
```
allow rw /{value1,#,comment,about,this,value,or,for,a,given,system},
```
change a leading # of a value in an assignment expression to a comment.
If the # is really supposed to lead the value, require it to be escaped
or in quotes.
ie.
```
@{var1}=value1 \#not_a_comment
```
Note: this could potentially break som policy if the # was used as the
leading character for a value in an assignment expression, but
is worth it to avoid the confusion.
Signed-off-by: John Johansen <john.johansen@canonical.com>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1255
Approved-by: Georgia Garcia <georgia.garcia@canonical.com>
Merged-by: John Johansen <john@jjmx.net>
The parser writes
sizeof(th)) + th_version + (char)0 + name + (char)0;
but the padding currently is computed as
sizeof(th)) + th_version + name + (char)0;
missing the internal (char)0, add 1 to the pad and fill to ensure
this is correct.
Reported-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Update the state machine readme to better reflect how the chfa is
encoded and works. It still needs a lot more but fixes several errors
in the doc and adds some info about state differential encoding, oobs,
and comb compression.
Signed-off-by: John Johansen <john.johansen@canonical.com>
technically a # leading a value in an assignment expression is allowed,
however people are also using it to a comment at the end of a line.
ie.
@{var1}=value1 # comment about this value or for a given system
this unsurprisingly leads to odd/unexpected behavior when the variable
is used.
allow rw /@{var1},
expands into
allow rw /{value1,#,comment,about,this,value,or,for,a,given,system},
change a leading # as value in an assignment expression to a comment.
If the # is really supposed to lead the value, require it to be escaped
or in quotes.
ie.
@{var1}=value1 \#not_a_comment
Note: this could potentially break som policy if the # was used as the
leading character for a value in an assignment expression, but
is worth it to avoid the confusion.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Shellcheck is complaining that some of the functions are never called,
but they are called from rc.apparmor.functions, causing a false
positive.
This issue only appears in shellcheck version 0.9.0, which is the one
used in ubuntu 24.04, that's why it only failed in the pipeline now.
Fixes: https://gitlab.com/apparmor/apparmor/-/issues/388
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Add a flag that allows setting the error code AppArmor will send when
an operation is denied. This should not be used normally.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
This updates the man page for the recent inet mediation patch.
This is an extension of MR 1202, it adds a patch that changes the anonymous ip address anon to be ip address none which is a better fit.
This patch adds documentation of the recent network changes which extended all network rules to support access permissions, and added address and port matching for inet and inet6 families.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1213
Approved-by: John Johansen <john@jjmx.net>
Merged-by: John Johansen <john@jjmx.net>
inet mediation allows specifying rules for sockets that don't have
a known address, whether because it is unbound or because the
kernel doesn't make the address available.
The current code uses the word anon for anonymous, but that has
proven to be unclear. Switch from using anon to none, to emphasize
that this is a case where there just isn't an address to use as
part of mediation.
Signed-off-by: John Johansen <john.johansen@canonical.com>
When a family is specified in the network rules, we have to make sure
the conditionals match the family. A netlink rule should not be able
to specify ip and port for local and remote (peer) sockets, for example.
When type or protocol is specified in network rules along with inet
conditionals, we should only generate rules for the families that
support those conditionals.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
The abstraction lxc/start-container shipped by the liblxc-common
package uses the following mount rule which was not allowed by our
regexes:
mount options=(rw, make-slave) -> **,
mount options=(rw, make-rslave) -> **,
Since in AppArmor regex ** includes '/' but * by itself doesn't, I'm
adding explicit support for **.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
The network cmp function was missing the new attributes added, causing
rules to be dropped.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
When the ip is not specified, then we should generate rules for ip
types: anonymous, ipv4 and ipv6. And that's the case for both local
and peer when considering recv and send permissions.
std::ostringstream does not have a copy constructor, that's why in
several places one can see streaming the string of one stream into
another.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
We want to be able to determine label in the future and build the
policy dfa based on its presence or not.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
According to the protocol expected by the kernel, the field
representing the ip size should be an enum instead of the actual ip
size. This is more future-proof.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Before the inet patches, protocol was not handled, so the information
was ignored. This patch introduces the ability to start mediating
protocol.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
The permission for network rules when the inet mediation was not
available, or for when the family was not af_inet or af_inet6 was
being generated as one that would allow anything. Make them specific
using perms.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
The layout for AF_INET and AF_INET6 rules were being applied to all
families, which causes failures in their mediation.
Fixes: ddefe11a ("parser: add fine grained conditionals to network rule")
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
- replace example calls of /etc/init.d/apparmor with apparmor.service
- drop /etc/init.d/apparmor in filelist
- replace /var/lib/apparmor/ with /var/cache/apparmor/
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1171
Approved-by: Georgia Garcia <georgia.garcia@canonical.com>
Merged-by: Christian Boltz <apparmor@cboltz.de>
- replace example calls of /etc/init.d/apparmor with apparmor.service
- drop /etc/init.d/apparmor in filelist
- replace /var/lib/apparmor/ with /var/cache/apparmor/
... based on /mount.cc mnt_opts_table
Several keywords and aliases were missing in flags_keywords:
- B
- M
- make-private
- make-rprivate
- make-rshared
- make-rslave
- make-runbindable
- make-shared
- make-slave
- make-unbindable
- r
- R
- read-only
- w
Also sort the keywords in the same order as in mount.cc.
Note: AARE handling is still a TODO.
After that, update the list of known parsing failures:
- several valid profiles are now correctly parsed
- some `"make-*" mount opt and an invalid src` bad profiles are no
longer detected as being invalid
A simple rule without conditionals need to be generated for when the
kernel does not support fine grained inet network mediation.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Options available are ip= and port= inside the peer group or outside,
representing local addresses and ports:
network peer=(ip=127.0.0.1 port=8080),
network ip=::1 port=8080 peer=(ip=::2 port=8081),
The 'ip' option supports both IPv4 and IPv6. Examples would be
ip=192.168.0.4, or ip=::578d
The 'port' option accepts a 16-bit unsigned integer. An example would
be port=1234
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
This commit add fixes for issues found in coverity's snapshot 70858.
- CID 323127: Performance inefficiencies (COPY_INSTEAD_OF_MOVE)
- CID 323125: Uninitialized members (UNINIT_CTOR)
I'm also removing Novell, Inc. from the copyright notice added by a
copy-paste error, and an unused variable left over from debugging.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
