commit 1fa45b7c1 ("parser: dfa minimization prepare for extended
permissions") removed implicit filtering of explicit denies in the
minimization pass (the information was ignored in building the set of
final accept states).
The filtering of explicit denies reduces the size of the produced
dfa. Since we need to be smarter about when explicit denies are
kept (eg. during complain mode), and most dfas are limited to 65k
states we currently need to filter explicit deny perms by default.
To compensate commit 2737cb2c2 ("parser: minimization - remove
unnecessary second minimization pass") moved the
apply_and_clear_deny() to before minimization. However its check to
apply removal denials before minimization is broken. Remove minimization
triggering apply_and_clear_deny() and just set the FILTER_DENY flag
by default, until we have better selection of rules/conditions where
explicit deny information should be carried through to the backend.
Fixes: 2737cb2c2 ("parser: minimization - remove unnecessary second minimization pass")
Signed-off-by: John Johansen <john.johansen@canonical.com>
The hfa stores next/check transitions in 16 bit fields to reduce memory
usage. However this means the state machine can on contain 2^16
states.
Allow the next/check tables to be 32 bit. This theoretically could allow
for 2^32 states however the base table uses the top 8 bits as flags
giving us only 2^24 bits to index into the next/check tables. With
most states having at least 1 transition this effectively caps the
number of states at 2^24.
To obtain 2^32 possible states a flags table needs to be added. Add
a skeleton around supporting a flags table, so we can note the remaining
work that needs to be done. This patch will only allow for 2^24 states.
Bug: https://gitlab.com/apparmor/apparmor/-/issues/419
Signed-off-by: John Johansen <john.johansen@canonical.com>
The use of xbits can not pass verification so we need to leave them
off this makes the profile a leaf profile.
Signed-off-by: John Johansen <john.johansen@canonical.com>
v1 of permstable32 has some broken verification checks. By using two
copies of a merged dfa and an xtable the same size of the permstable
we can work around the issue.
Signed-off-by: John Johansen <john.johansen@canonical.com>
If extended permissions are supported use them. We need to build a
permission table and set the accept state of the chfa up as an index
into the table.
For now map the front end permission layout into the old format and
then convert that to the perms table just as the kernel does.
Signed-off-by: John Johansen <john.johansen@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>
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>
Add a flag that allows setting the signal used to kill the process.
This should not be normally used but can be very useful when
debugging applications, interaction with apparmor.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Instead of having multiple tables, since we have room post split
of optimization and dump flags just move all the optimization and
dump flags into a common table.
We can if needed switch the flag entry size to a long in the future.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Add the ability to control whether rule merging is done.
TODO: in the furture cleanup display of flags split accross two tables
Signed-off-by: John Johansen <john.johansen@canonical.com>
In preparation for more flags (not all of the backend dfa based),
rework the optimization and dump flag handling which has been exclusively
around the dfa up to this point.
- split dfa control and dump flags into separate fields. This gives more
room for new flags in the existing DFA set
- rename DFA_DUMP, and DFA_CONTROL to CONTROL_DFA and DUMP_DFA as
this will provide more uniform naming for none dfa flags
- group dump and control flags into a structure so they can be passed
together.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Profile includes can be setup to loop and expand in a pathalogical
manner that causes build failures. Fix this by caching which includes
have already been seen in a given profile context.
In addition this can speed up some profile compiles, that end up
re-including common abstractions. By not only deduping the files
being included but skipping the need to reprocess and dedup the
rules within the include.
Fixes: https://bugzilla.suse.com/show_bug.cgi?id=1184779
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/743
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve.beattie@canonical.com>
Add basic ability to treat a warning as an error and abort the compile
by specifying the new option --Werror.
--Werror
will turn all warnings into errors. Where if an warning type is
specified only that type of warning will be turned into an error.
--Werror=deprecated.
The full list of supported warning types can be found by using
apparmor_parser --help=warn
or
apparmor_parser --help=Werror
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/600
Signed-off-by: John Johansen <john.johansen@canonical.com>
Make all warnings that go through pwarn() controllable by warning
flags. This adds several new warning control flags, documented in
--help=warn
Convert --debug-cache to be unified with warning flags. So it can be
set by either
--debug-cache
or
--warn=debug-cache
Also add an "all" option to be able to turn on all warnings.
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/600
Signed-off-by: John Johansen <john.johansen@canonical.com>
The warn_once() function is duplicated in 6 different places. A common,
reusable version has been added to parser_common.c.
Signed-off-by: Mike Salvatore <mike.salvatore@canonical.com>
Add basic support for policy to specify a feature abi. Under the
current implementation the first feature abi specified will be
used as the policy abi for the entire profile.
If no feature abi is defined before rules are processed then the
default policy abi will be used.
If multiple feature abi rules are encountered and the specified
abi is different then a warning will be issued, and the initial abi
will continue to be used. The ability to support multiple policy
feature abis during a compile will be added in a future patch.
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/491
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
The features abi adds the ability to track the policy abi separate
from the kernel. This allow the compiler to determine whether policy
was developed with a certain feature in mind, eg. unix rules.
This allows the compiler to know whether it should tell the kernel to
enforce the feature if the kernel supports the rule but the policy
doesn't use it.
To find if a feature is supported we take the intersection of what is
supported by the policy and what is supported by the kernel.
Policy encoding features like whether to diff_encode policy are not
influenced by policy so these remain kernel only features.
In addition to adding the above intersection of policy rename
--compile-features to --policy-features as better represents what it
represents. --compile-features is left as a hidden item for backwards
compatibility.
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/491
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
Check if the current kernel supports stacking. If not, ensure that named
transitions (exec, change_profile, etc.) do not attempt to stack their
targets.
Also, set up the change_profile vector according to whether or not the
kernel supports stacking. Earlier kernels expect the policy namespace to
be in its own NUL-terminated vector element rather than passing the
entire label (namespace and profile name) as a single string to the
kernel.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2.9.x and 2.10 had some time stamp bugs around cache handling that
result in the cache getting a wrong time stamp, and then not getting
correctly updated when policy changes.
Force cache recompiles for these versions by bumping the parser abi
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
Create new, ref, and unref functions for aa_kernel_interface. The "new"
function allows for the caller to pass in an aa_features object that is
then used to check if the kernel supports set load operations.
Additionally, the "new" function allows for the apparmorfs path to be
discovered once instead of during every policy load.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Currently the apparmor parser warns about rules that are not enforced or
downgraded. This is a problem for distros that are not carrying the out of
tree kernel patches, as most profile loads result in warnings.
Change the behavior to not output a message unless a warn flag is passed.
This patch adds 2 different warn flags
--warn rule-downgraded # warn if a rule is downgraded
--warn rule-not-enforced # warn if a rule is not enforced at all
If the warnings are desired by default the flags can be set in the
parser.conf file.
v2 of patch
- update man page
- add --warn to usage statement
- make --quiet clear warn flags
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
This patch implements parsing of fine grained mediation for unix domain
sockets, that have abstract and anonymous paths. Sockets with file
system paths are handled by regular file access rules.
The unix network rules follow the general fine grained network
rule pattern of
[<qualifiers>] af_name [<access expr>] [<rule conds>] [<local expr>] [<peer expr>]
specifically for af_unix this is
[<qualifiers>] 'unix' [<access expr>] [<rule conds>] [<local expr>] [<peer expr>]
<qualifiers> = [ 'audit' ] [ 'allow' | 'deny' ]
<access expr> = ( <access> | <access list> )
<access> = ( 'server' | 'create' | 'bind' | 'listen' | 'accept' |
'connect' | 'shutdown' | 'getattr' | 'setattr' |
'getopt' | 'setopt' |
'send' | 'receive' | 'r' | 'w' | 'rw' )
(some access modes are incompatible with some rules or require additional
parameters)
<access list> = '(' <access> ( [','] <WS> <access> )* ')'
<WS> = white space
<rule conds> = ( <type cond> | <protocol cond> )*
each cond can appear at most once
<type cond> = 'type' '=' ( <AARE> | '(' ( '"' <AARE> '"' | <AARE> )+ ')' )
<protocol cond> = 'protocol' '=' ( <AARE> | '(' ( '"' <AARE> '"' | <AARE> )+ ')' )
<local expr> = ( <path cond> | <attr cond> | <opt cond> )*
each cond can appear at most once
<peer expr> = 'peer' '=' ( <path cond> | <label cond> )+
each cond can appear at most once
<path cond> = 'path' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )
<label cond> = 'label' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')')
<attr cond> = 'attr' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )
<opt cond> = 'opt' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )
<AARE> = ?*[]{}^ ( see man page )
unix domain socket rules are accumulated so that the granted unix
socket permissions are the union of all the listed unix rule permissions.
unix domain socket rules are broad and general and become more restrictive
as further information is specified. Policy may be specified down to
the path and label level. The content of the communication is not
examined.
Some permissions are not compatible with all unix rules.
unix socket rule permissions are implied when a rule does not explicitly
state an access list. By default if a rule does not have an access list
all permissions that are compatible with the specified set of local
and peer conditionals are implied.
The 'server', 'r', 'w' and 'rw' permissions are aliases for other permissions.
server = (create, bind, listen, accept)
r = (receive, getattr, getopt)
w = (create, connect, send, setattr, setopt)
In addition it supports the v7 kernel abi semantics around generic
network rules. The v7 abi removes the masking unix and netlink
address families from the generic masking and uses fine grained
mediation for an address type if supplied.
This means that the rules
network unix,
network netlink,
are now enforced instead of ignored. The parser previously could accept
these but the kernel would ignore anything written to them. If a network
rule is supplied it takes precedence over the finer grained mediation
rule. If permission is not granted via a broad network access rule
fine grained mediation is applied.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Commit r2456 fixes a bug in the parsers compilation that can result
policy failures. Unfortunately this Bug slipped into the wild and
shipped in at least one distro.
Bump the parser abi so that parsers that have the fix will invalid
existing cache files, and recompile policy to ensure the fix is applied.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
v3: fix freeing of filename when undefined
v2: address tyhicks feedback
refactor to have a common write routine
fix issue with set profile load being done even if !kernel_load
Profile loads from cache files that contain multiple profiles can
result in multiple reloads of the same profile or error messages about
failure to load profiles if the --add option is used. eg.
apparmor="STATUS" operation="profile_load"
name="/usr/lib/apache2/mpm-prefork/apache2" pid=8631
comm="apparmor_parser"
<sth0R> [82932.058388] type=1400 audit(1395415826.937:616):
apparmor="STATUS" operation="profile_load" name="DEFAULT_URI" pid=8631
comm="apparmor_parser"
<sth0R> [82932.058391] type=1400 audit(1395415826.937:617):
apparmor="STATUS" operation="profile_load"
name="HANDLING_UNTRUSTED_INPUT" pid=8631 comm="apparmor_parser"
<sth0R> [82932.058394] type=1400 audit(1395415826.937:618):
apparmor="STATUS" operation="profile_load" name="phpsysinfo" pid=8631
comm="apparmor_parser"
<sth0R> [82932.059058] type=1400 audit(1395415826.937:619):
apparmor="STATUS" operation="profile_replace" info="profile can not be
replaced" error=-17
name="/usr/lib/apache2/mpm-prefork/apache2//DEFAULT_URI" pid=8631
comm="apparmor_parser"
<sth0R> [82932.059574] type=1400 audit(1395415826.937:620):
apparmor="STATUS" operation="profile_replace" info="profile can not be
replaced" error=-17
name="/usr/lib/apache2/mpm-prefork/apache2//HANDLING_UNTRUSTED_INPUT"
pid=8631 comm="apparmor_parser"
The reason this happens is that the cache file is a container that
can contain multiple profiles in sequential order
profile1
profile2
profile3
The parser loads the entire cache file to memory and the writes the
whole file to the kernel interface. It then skips foward in the file
to the next profile and reloads the file from that profile into
the kernel.
eg. First load
profile1
profile2
profile3
advance to profile2, do second load
profile2
profile3
advance to profile3, do third load
profile3
With older kernels the interface would stop after the first profile and
return that it had processed the whole file, thus while wasting compute
resources copying extra data no errors occurred. However newer kernels
now support atomic loading of multipe profiles, so that all the profiles
passed in to the interface get processed.
This means on newer kernels the current parser load behavior results
in multiple loads/replacements when a cache file contains more than
one profile (note: loads from a compile do not have this problem).
To fix this, detect if the kernel supports atomic set loads, and load
the cache file once. If it doesn't only load one profile section
from a cache file at a time.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
ptrace rules currently take the form of
ptrace [<ptrace_perms>] [<peer_profile_name>],
ptrace_perm := read|trace|readby|tracedby
ptrace_perms := ptrace_perm | '(' ptrace_perm+ ')'
After having used the cross check (permission needed in both profiles)
I am not sure it is correct for ptrace.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Add signal rules and make sure the parser encodes support for them
if the supported feature set reports supporting them.
The current format of the signal rule is
[audit] [deny] signal [<signal_perms>] [<signal_set>] <target_profile>,
signal_perm := 'send'|'receive'|'r'|'w'|'rw'
signal_perms := <signal_perm> | '(' <signal_perm> ([,]<signal_perm>)* ')'
signal := ("hup"|"int"|"quit"|"ill"|"trap"|"abrt"|"bus"|"fpe"|"kill"|
"usr1"|"segv"|"usr2"|"pipe"|"alrm"|"term"|"tkflt"|"chld"|
"cont"|"stop"|"stp"|"ttin"|"ttou"|"urg"|"xcpu"|"xfsz"|"vtalrm"|
"prof"|"winch"|"io"|"pwr"|"sys"|"emt"|"exists")
signal_set := set=<signal> | '(' <signal> ([,]<signal>)* ')'
it does not currently follow the peer=() format, and there is some question
as to whether it should or not. Input welcome.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
This will allow for the parser to invalidate its caches separate of whether
the kernel policy version has changed. This can be desirable if a parser
bug is discovered, a new version the parser is shipped and we need to
force cache files to be regenerated.
Policy current stores a 32 bit version number in the header binary policy.
For newer policy (> v5 kernel abi) split this number into 3 separate
fields policy_version, parser_abi, kernel_abi.
If binary policy with a split version number is loaded to an older
kernel it will be correctly rejected as unsupported as those kernels
will see it as a none v5 version. For kernels that only support v5
policy on the kernel abi version is written.
The rules for policy versioning should be
policy_version:
Set by text policy language version. Parsers that don't understand
a specified version may fail, or drop rules they are unaware of.
parser_abi_version:
gets bumped when a userspace bug is discovered that requires policy be
recompiled. The policy version could be reset for each new kernel version
but since the parser needs to support multiple kernel versions tracking
this is extra work and should be avoided.
kernel_abi_version:
gets bumped when semantic changes need to be applied. Eg unix domain
sockets being mediated at connect.
the kernel abi version does not encapsulate all supported features.
As kernels could have different sets of patches supplied. Basic feature
support is determined by the policy_mediates() encoding in the policydb.
As such comparing cache features to kernel features is still needed
to determine if cached policy is best matched to the kernel.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Tag start of entries in the policydb as being mediated. This makes
the start state for any class being mediated be none 0. The kernel
can detect this to determine whether the parser expected mediation
for the class.
This is just a way of encoding what features expect mediation within
the policydb it self so that a separate table isn't needed.
This is also used to indicate the new unix semantics for mediation of
unix domain sockets on connect should be applied.
Note: this does cause a fail open on situation on Ubuntu Saucy, which
did not properly indicate support. That is if a kernel using this patch
is installed on an Ubuntu Saucy system, unix domain socket mediation
on connect won't happen, instead the older behavior will be applied.
This won't cause policy failures as it is less strict than what
Ubuntu Saucy applies.
This is necessary so that AppArmor can properly function on older
userspaces without a compile time configuration on the kernel to determine
behavior. A kernel expecting this behavior will function correctly
with all old userspaces expect it will not enforce connect time mediation
on Ubuntu Saucy. However Ubuntu does not support Trusty (or newer)
kernels as backports to Saucy, so this does not break them.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
The features file patch broke detection of network support.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
This was part of the original minimization patch, but got dropped when
applying to bzr. Again bzr status didn't show any files out of place
nor did the patching fail :(
Signed-off-by: John Johansen <john.johansen@canonical.com>
When a parser that is aware of dbus rules is running under a kernel
that is unaware of dbus rules, the parser should ignore the dbus rules
instead of attempting to load them into the kernel. Otherwise, the
kernel will reject the entire profile, leaving the application
unconfined.
Similar to what is done for mount rules, the features listed in
apparmorfs should be checked to see if dbus is supported under the
current kernel.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
This patch addresses a bunch of the compiler string conversion warnings
that were introduced with the C++-ification patch.
Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
change_hat 1.4 was an experiement is more directly controlling change_hat
by adding hat rulles to the profile. It has not been used since the
original experiment (4 years). So remove it
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
This conversion is nothing more than what is required to get it to
compile. Further improvements will come as the code is refactored.
Unfortunately due to C++ not supporting designated initializers, the auto
generation of af names needed to be reworked, and "netlink" and "unix"
domain socket keywords leaked in. Since these where going to be added in
separate patches I have not bothered to do the extra work to replace them
with a temporary place holder.
Signed-off-by: John Johansen <john.johansen@canonical.com>
[tyhicks: merged with dbus changes and memory leak fixes]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
Remove use of AARE_DFA as the alternate pcre matching engine was removed
years ago.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
Newer versions of AppArmor use a features directory instead of a file
update the parser to use this to determine features and match string
This is just a first pass at this to get things up quickly. A much
more comprehensive rework that can parse and use the full information
set is needed.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Previously permission information was thrown away early and permissions
where packed to their CHFA form at the start of DFA construction. Because
of this permissions hashing to setup the initial DFA partitions was
required as x transition conflicts, etc. could not be resolved.
Move the mapping of permissions to CHFA construction, and track the full
permission set through DFA construction. This allows removal of the
perm_hashing hack, which prevented a full minimization from happening
in some DFAs. It also could result in x conflicts not being correctly
detected, and deny rules not being fully applied in some situations.
Eg.
pre full minimization
Created dfa: states 33451
Minimized dfa: final partitions 17033
with full minimization
Created dfa: states 33451
Minimized dfa: final partitions 9550
Dfa minimization no states removed: partitions 9550
The tracking of deny rules through to the completed DFA construction creates
a new class of states. That is states that are marked as being accepting
(carry permission information) but infact are non-accepting as they
only carry deny information. We add a second minimization pass where such
states have their permission information cleared and are thus moved into the
non-accepting partion.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
asprintf is marked with warn_unused_result and its return value should
not be ignored, even casting to (void) will not remove this warning.
The current code ignored the result and used the value of newfmt to
make a decision. This is however not correct in that according to the
asprintf man page newfmt is undefined if asprintf returns an error.
Fix the warning and error by using the return value of asprintf
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-By: Steve Beattie <sbeattie@ubuntu.com>
The module interface calls for names with namespaces to be in the format of
:namespace:profile or :namespace://profile
but the parser was generating
namespace:profile
causing profile lookup to fail, or removal of the wrong profile as it was
done against the current namespace, instead of the specified namespace
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
