The parser pot file should have been updated before beta. Make
sure it is up to date with the current code.
Signed-off-by: John Johansen <john.johansen@canonical.com>
utils: ignore peer when parsing logs for non-peer access modes
Some access modes (create, setopt, getopt, bind, shutdown, listen,
getattr, setattr) cannot be used with a peer in network rules.
Due to how auditing is implemented in the kernel, the peer information
might be available in the log (as faddr= but not daddr=), which causes
a failure in log parsing.
When parsing the log, check if that's the case and ignore the peer,
avoiding the exception on the NetworkRule constructor.
Fixes: https://gitlab.com/apparmor/apparmor/-/issues/427
Reported-by: Evan Caville <evan.caville@canonical.com>
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Closes#427
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1314
Approved-by: Christian Boltz <apparmor@cboltz.de>
Merged-by: John Johansen <john@jjmx.net>
The wording of "scrub the environment" with respect to execution modes is misleading, because a quick read of it could imply that it removes all environment variables. However, it actually enables ld.so's secure-execution mode, which removes a very limited subset of them. This MR rewords the relevant documentation and prompts. If proper environment variable filtering is added later, the documentation can be updated again then.
Synchronizes-with:
- Wiki page update, which I can do after this MR is approved
- Kernel patch to update wording of debug logs (patch submitted to the Apparmor mailing list [here](https://lists.ubuntu.com/archives/apparmor/2024-August/013339.html))
Things that may need updating first:
- Translations: attempting to update `utils/po/apparmor-utils.pot` resulted in a bunch of unrelated changes, so I'd like to ask about translation statuses before making a commit that updates that file properly.
- Adding info on which libc's actually behave differently based on AT_SECURE: glibc and musl libc both do, but they may do subtly different things. I don't know about other libc's.
Signed-off-by: Ryan Lee <ryan.lee@canonical.com>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1315
Approved-by: John Johansen <john@jjmx.net>
Merged-by: Ryan Lee <rlee287@yahoo.com>
Some access modes (create, setopt, getopt, bind, shutdown, listen,
getattr, setattr) cannot be used with a peer in network rules.
Due to how auditing is implemented in the kernel, the peer information
might be available in the log (as faddr= but not daddr=), which causes
a failure in log parsing.
When parsing the log, check if that's the case and ignore the peer,
avoiding the exception on the NetworkRule constructor.
Fixes: https://gitlab.com/apparmor/apparmor/-/issues/427
Reported-by: Evan Caville <evan.caville@canonical.com>
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
io_uring and userns mediation are encoding permissions on the class
byte. This is a mistake that should never have been allowed.
With the addition of rule priorities the class byte mediates rule,
that ensure the kernel can determine a class is being mediated is
given the highest priority possible, to ensure class mediation can not
be removed by a deny rule. See
61b7568e1 ("parser: bug fix mediates_X stub rules.")
for details.
Unfortunately this breaks rule classes that encode permissions on the
class byte, because those rules will always have a lower priority and
the class mediates rule will always be selected over them resulting in
only the class mediates permission being on the rule class state.
Fix this by adding the mediaties class rules for these rule classes
with the lowest priority possible. This means that any rule mediating
the class will wipe out the mediates class rule. So add a new mediates
class rule at the same priority, as the rule being added.
This is a naive implementation and does result in more mediates rules
being added than necessary. The rule class could keep track of the
highest priority rule that had been added, and use that to reduce the
number of mediates rules it adds for the class.
Technically we could also get away with not adding the rules for allow
rules, as the kernel doesn't actually check the encoded permission but
whether the class state is not the trap state. But it is required with
deny rules to ensure the deny rule doesn't result in permissions being
removed from the class, resulting in the kernel thinking it is
unmediated. We also want to ensure that mediation is encoded for other
rule types like prompt, and in the future the kernel could check the
permission so we do want to guarantee that the class state has the
MAY_READ permission on it.
Note: there is another set of classes (file, mqueue, dbus, ...) which
encodes a default rule permission as
class .* <perm>
this encoding is unfortunate in that it will also add the permission
to the class byte, but also sets up following states with the permission.
thankfully, this accespt anything, including nothing generally isn't
valid in the nothing case (eg. a file without any absolute name). For
this set of classes, the high priority mediates rule just ensures
that the null match case does not have permission.
Fixes: 61b7568e1 parser: bug fix mediates_X stub rules.
Signed-off-by: John Johansen <john.johansen@canonical.com>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1307
Approved-by: Georgia Garcia <georgia.garcia@canonical.com>
Merged-by: John Johansen <john@jjmx.net>
af_protos.h is a generated table of the protocols created by looking
for definitions of IPPROTO_* in netinet/in.h. Depending on the
architecture, the order of the table may change when using -dM in the
compiler during the extraction of the defines.
This causes an issue because there is more than one IPPROTO defined
by the value 0: IPPROTO_IP and IPPROTO_HOPOPTS which is a header
extension used by IPv6. So if IPPROTO_HOPOPTS was first in the table,
then protocol=0 in the audit logs would be translated to hopopts.
This caused a failure in arm 32bit:
Output doesn't match expected data:
--- ./test_multi/testcase_unix_01.out 2024-08-15 01:47:53.000000000 +0000
+++ ./test_multi/out/testcase_unix_01.out 2024-08-15 23:42:10.187416392 +0000
@@ -12,7 +12,7 @@
Peer Addr: @test_abstract_socket
Network family: unix
Socket type: stream
-Protocol: ip
+Protocol: hopopts
Class: net
Epoch: 1711454639
Audit subid: 322
By the time protocol is resolved in grammar.y, we don't have have
access to the net family to check if it's inet6. Instead of making
protocol dependent on the net family, make the order of the
af_protos.h table consistent between architectures using -dD.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1309
Approved-by: John Johansen <john@jjmx.net>
Merged-by: Georgia Garcia <georgia.garcia@canonical.com>
af_protos.h is a generated table of the protocols created by looking
for definitions of IPPROTO_* in netinet/in.h. Depending on the
architecture, the order of the table may change when using -dM in the
compiler during the extraction of the defines.
This causes an issue because there is more than one IPPROTO defined
by the value 0: IPPROTO_IP and IPPROTO_HOPOPTS which is a header
extension used by IPv6. So if IPPROTO_HOPOPTS was first in the table,
then protocol=0 in the audit logs would be translated to hopopts.
This caused a failure in arm 32bit:
Output doesn't match expected data:
--- ./test_multi/testcase_unix_01.out 2024-08-15 01:47:53.000000000 +0000
+++ ./test_multi/out/testcase_unix_01.out 2024-08-15 23:42:10.187416392 +0000
@@ -12,7 +12,7 @@
Peer Addr: @test_abstract_socket
Network family: unix
Socket type: stream
-Protocol: ip
+Protocol: hopopts
Class: net
Epoch: 1711454639
Audit subid: 322
By the time protocol is resolved in grammar.y, we don't have have
access to the net family to check if it's inet6. Instead of making
protocol dependent on the net family, make the order of the
af_protos.h table consistent between architectures using -dD.
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
io_uring and userns mediation are encoding permissions on the class
byte. This is a mistake that should never have been allowed.
With the addition of rule priorities the class byte mediates rule,
that ensure the kernel can determine a class is being mediated is
given the highest priority possible, to ensure class mediation can not
be removed by a deny rule. See
61b7568e1 ("parser: bug fix mediates_X stub rules.")
for details.
Unfortunately this breaks rule classes that encode permissions on the
class byte, because those rules will always have a lower priority and
the class mediates rule will always be selected over them resulting in
only the class mediates permission being on the rule class state.
Fix this by adding the mediaties class rules for these rule classes
with the lowest priority possible. This means that any rule mediating
the class will wipe out the mediates class rule. So add a new mediates
class rule at the same priority, as the rule being added.
This is a naive implementation and does result in more mediates rules
being added than necessary. The rule class could keep track of the
highest priority rule that had been added, and use that to reduce the
number of mediates rules it adds for the class.
Technically we could also get away with not adding the rules for allow
rules, as the kernel doesn't actually check the encoded permission but
whether the class state is not the trap state. But it is required with
deny rules to ensure the deny rule doesn't result in permissions being
removed from the class, resulting in the kernel thinking it is
unmediated. We also want to ensure that mediation is encoded for other
rule types like prompt, and in the future the kernel could check the
permission so we do want to guarantee that the class state has the
MAY_READ permission on it.
Note: there is another set of classes (file, mqueue, dbus, ...) which
encodes a default rule permission as
class .* <perm>
this encoding is unfortunate in that it will also add the permission
to the class byte, but also sets up following states with the permission.
thankfully, this accespt anything, including nothing generally isn't
valid in the nothing case (eg. a file without any absolute name). For
this set of classes, the high priority mediates rule just ensures
that the null match case does not have permission.
Fixes: 61b7568e1 parser: bug fix mediates_X stub rules.
Signed-off-by: John Johansen <john.johansen@canonical.com>
This enables adding a priority to a rules in policy.
Rules have a default priority of 0. The priority prefix can be added
before the other currently support rule prefixes, ie.
[priority prefix][audit qualifier][rule mode][owner]
If present a numerical priority can be assigned to the rule, where the
greater the number the higher the priority. Eg.
priority=1 audit file r /etc/passwd,
priority=-1 deny file w /etc/**,
Rule priority allows the rule with the highest priority to completely
override lower priority rules where they overlap. Within a given
priority level rules will accumulate in standard apparmor fashion.
Eg. given
priority=1 w /*c,
priority=0 r /a*,
priority=-1 k /*b*,
/abc, /bc, /ac .. will have permissions of w
/ab, /abb, /aaa, .. will have permissions of r
/b, /bcb, /bab, .. will have permissions of k
User specified rule priorities are currently capped at the arbitrary
values of 1000, and -1000.
Notes:
* not all rule types support the priority prefix. Rukes like
- network
- capability
- rlimits
need to be reworked to properly preserve the policy rule structure.
* this patch does not support priority on rule blocks
* this patch does not support using a variable in the priority value.
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1261
Approved-by: John Johansen <john@jjmx.net>
Merged-by: John Johansen <john@jjmx.net>
the ix portion of file, causes x conflicts in regular priority. The
long term goal is to fix this by using dominance for x rules. But in
the mean time we can fix by giving the ix portion of the rule a
reduced priority.
Signed-off-by: John Johansen <john.johansen@canonical.com>
This enables adding a priority to a rules in policy, finishing out the
priority work done to plumb priority support through the internals in
the previous patch.
Rules have a default priority of 0. The priority prefix can be added
before the other currently support rule prefixes, ie.
[priority prefix][audit qualifier][rule mode][owner]
If present a numerical priority can be assigned to the rule, where the
greater the number the higher the priority. Eg.
priority=1 audit file r /etc/passwd,
priority=-1 deny file w /etc/**,
Rule priority allows the rule with the highest priority to completely
override lower priority rules where they overlap. Within a given
priority level rules will accumulate in standard apparmor fashion.
Eg. given
priority=1 w /*c,
priority=0 r /a*,
priority=-1 k /*b*,
/abc, /bc, /ac .. will have permissions of w
/ab, /abb, /aaa, .. will have permissions of r
/b, /bcb, /bab, .. will have permissions of k
User specified rule priorities are currently capped at the arbitrary
values of 1000, and -1000.
Notes:
* not all rule types support the priority prefix. Rukes like
- network
- capability
- rlimits need to be reworked
need to be reworked to properly preserve the policy rule structure.
* this patch does not support priority on rule blocks
* this patch does not support using a variable in the priority value.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Currently mediates_X stub rules are added to the dfa to ensure a valid
transition state will exist if X should be mediated. The kernel uses
this to test whether the dfa supports certain mediation classes.
Unfortunately the mediates stub rules can be removed by other rules,
combined with minimization. In the allow case this is not a problem,
as if the stub rule is removed it will be due to state merging and the
test will still be valid. Unfortunately the deny case can wipe out the
stub rule in a couple of cases, meaning the when the kernel tests that
its in a valid state for mediation it will fail and treat the dfa as
not mediating the rule type, which results in allowing instead of
denying.
Fix this by making sure mediated stub rules can't be overridden by a
deny rule by giving them maximum priority.
Note: there is another issue with stub rule elimination in the allow
case. It will can cause equality tests to fail when combined
with priority rules, because the stub rules where added at
priority 0 and an actual rule of higher priority could
completely override it removing the permission on the stub rule.
This issue will be caught by the equality.sh tests in the
following patch that exposes priority to rules in policy.
Signed-off-by: John Johansen <john.johansen@canonical.com>
The prefix comparison doesn't need to do as many operations as it is
doing, and the operator< can be based on the cmp() fn further reducing
the chance that the code will get out of sync if prefixes are changed.
Signed-off-by: John Johansen <john.johansen@canonical.com>
the parser front end boolean is used for both boolean and integer
values. This is confusing when integer values different than 1 or 0
are being assigned to and from boolean.
Split its uses into the correct semantic boolean and integer cases.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Currently use of extended perms are dependent on prompt rules being present
in policy. Switch to using extended perms if they are supported.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Moving apply_and_clear_deny() before the first minimization pass, which
was necessary to propperly support building accept information for
older none extended permission dfas, allows us to also get rid of doing a
second minimization pass if we want to force clearing explicit deny
info from extended permission tables.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Instead of compressing the permission set into 128 bit and using that
as the index in the permission map, just use the permissions directly
as the index into the permission map.
Note: this will break equality and minimization tests. Because deny
is not being cleared it will result in more partitions in the initial
setup. This will be addressed and the tests will be fixed in a follow
on patch.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Hash minimization was removed in
f0b154528 Fix dfa minimization
however some remnants of minimization remained. A comment and the use
of the hash but only as a 0 value. Drop this dead code and comment.
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>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1303
Approved-by: Georgia Garcia <georgia.garcia@canonical.com>
Merged-by: John Johansen <john@jjmx.net>
If the state machine does not requires more than 2^16 states use the
dfa16 encoding for next/check tables to keep the dfa size small.
Bug: https://gitlab.com/apparmor/apparmor/-/issues/419
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>
This adds support for prompt rules and the beginning of support for extended permissions. Currently extended permissions are only used if a prompt rule is used in policy.
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1305
Approved-by: John Johansen <john@jjmx.net>
Merged-by: John Johansen <john@jjmx.net>
Older kernels do not support an xtable grouped with the policy dfa.
The presence of a policy.dfa does not indicate whether we should create
an xtable with the policy dfa.
Instead the check should be if the kernel supports the extended
permstable32 format.
Signed-off-by: John Johansen <john.johansen@canonical.com>
__uint128 is not supported by gcc on 32 bit architectures so rework
the 128 bit map key to be a pair of 64bit numbers.
Signed-off-by: John Johansen <john.johansen@canonical.com>
switch permission bits to use perm32_t type. This is just annotating
the code as it is no different than uint32_t at this time.
We do not convert the accept values as they may be mapped permission
bits or they may be and index value.
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>
There are two distinct declarations of perms_t.
rule.h: typedef uint32_t perms_t
hfa.h: class perms_t
these definitions clash when the front end and backend share more info.
To avoid this rename rule.h to perm32_t, and move the definition into
perms.h and use it in struct aa_perms.
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>
