backport of dev commit 2510
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>
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>
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>
