Commit graph

150 commits

Author SHA1 Message Date
John Johansen
ee1a5e6e18 parser: enable extended perms if supported by the kernel
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>
2024-08-14 17:15:24 -07:00
John Johansen
2737cb2c2b parser: minimization - remove unnecessary second minimization pass
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>
2024-08-14 17:15:24 -07:00
John Johansen
89673d0c5e parser: don't set xbits when using permstable32_v1
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>
2024-08-14 15:47:13 -07:00
John Johansen
5bd2271189 pass prompt info down into the backend for mapping
mapping for PROMPT_DEV needs to know that we should prompt
2024-08-14 15:47:13 -07:00
John Johansen
1d0d1fd0c2 parser: and prompt-compat control flag
Allow contronling which prompt compat mode fallback is used.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2024-08-14 15:47:13 -07:00
John Johansen
5c2bd20720 parser: pass rule mode prompt through to backend
Signed-off-by: John Johansen <john.johansen@canonical.com>
2024-08-14 15:47:13 -07:00
John Johansen
e4890e6ba1 parser: Add work around for buggy permstable32
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>
2024-08-14 15:45:58 -07:00
John Johansen
2e18cb9aed parser: rename rules.h perms_t to perm32_t
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>
2024-08-14 14:39:18 -07:00
John Johansen
e29f5ce5f3 parser: if extended perms are supported by the kernel build a permstable
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>
2024-08-14 14:39:18 -07:00
Georgia Garcia
dc48e1417d parser: don't add mediation classes to unconfined profiles
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>
2024-06-13 15:22:31 -03:00
Georgia Garcia
35f25a251b parser: fix coverity issues found in snapshot 70858
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>
2024-02-28 10:24:08 -03:00
Georgia Garcia
75ca0e7919 parser: track leading zeros required for ipv6 range regex generator
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2023-09-07 00:13:52 -07:00
Georgia Garcia
fb5f59024c parser: add uppercase hex on regex range generator
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2023-09-07 00:13:42 -07:00
Georgia Garcia
a71ac76e6d parser: add regex generator for range
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2023-09-07 00:13:29 -07:00
Georgia Garcia
820f1fb5f2 parser: refactor network to use rule class as its base.
There is one significant difference in the encoding of the network
rules. Before this change, when the parser was encoding a "network,"
rule, it would generate an entry for every family and every
type/protocol. After this patch the parser should generate an entry
for every family, but the type/protocol is changed to .. in the pcre
syntax. There should be no difference in behavior.

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2023-09-07 00:12:51 -07:00
John Johansen
501e87a3f2 parser: Cleanup parser control flags, so they display as expected to user
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>
2023-07-08 19:58:59 -07:00
John Johansen
e84e481263 parser: cleanup and rework optimization and dump flag handling
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>
2023-07-07 17:47:41 -07:00
John Johansen
7d9958890f parser: finish basic infrastructure for rule merging
Currently only file rules get merged. Finish adding basic support
for rule merging and make the default the behavior to dedup
merge rules that are exact matches.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-07-07 17:35:37 -07:00
John Johansen
dbca8ebb89 parser: Improve the rule skip test.
Rules can be marked as being deleted/merged, and should be skipped on
further processing.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-07-05 04:40:27 -07:00
John Johansen
fef3eb3693 Merge add userspace support for io_uring mediation
```
io_uring rules have the following format:

io_uring [<access_mode>] [<label>],
access_mode := 'sqpoll'|'override_creds'
label := 'label' '=' <target label>
```

You can use the following kernel tree with the io_uring mediation patch to test this feature https://gitlab.com/georgiag/apparmor-kernel/-/commits/io_uring

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/993
Approved-by: John Johansen <john@jjmx.net>
Merged-by: John Johansen <john@jjmx.net>
2023-06-29 21:38:02 +00:00
Christian Boltz
e408d03a5b
Fix use-after-free of 'name' in parser_regex.c
'name' gets used in the error message. Make sure it only gets freed
afterwards.

This bug was introduced in be0d2fa947 /
https://gitlab.com/apparmor/apparmor/-/merge_requests/727

Fixes coverity CID 254465:  Memory - illegal accesses  (USE_AFTER_FREE)
2023-05-29 22:16:09 +02:00
Georgia Garcia
e5e920d178 parser: add parser support for io_uring mediation
io_uring rules have the following format:

io_uring [<access_mode>] [<label>],
access_mode := 'sqpoll'|'override_creds'
label := 'label' '=' <target label>

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2023-05-03 16:03:52 +02:00
John Johansen
b061155c9a parser: add flags to rule_t
In preparation for file rules and rule duplication removal add
flags to rule_t with the first flag indicating if the rule is
deleted.

We do this instead of actually deleting the rule so we can hold
on to the rule for debug and printing output in the future.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:21:19 -07:00
John Johansen
355730d8c7 parser: convert deny flag from bool to rule_mode
We need to be able to support more rule types than allow and deny so
convert to an enum.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:21:11 -07:00
John Johansen
fdf5b062a9 parser: fixup audit struct to audit enum
This removes the struct wrapper used in the previous patch to ensure
that all uses are properly converted.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:12:35 -07:00
John Johansen
7a318d99f2 parser: convert audit from bool to enum
Audit control support is going to be extended to support allowing
policy to which rules should quiet auditing. Update the frontend
internals to prepare for this.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:08:20 -07:00
John Johansen
134e95f783 parser: fixup remove struct from the audit bool conversion
This removes the struct wrapper used in the previous patch to ensure
that all uses are properly converted.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 01:08:25 -07:00
John Johansen
44f3be091a parser: convert the stored audit from a bit mask to a bool
This delays the convertion of the audit flag until passing to the
backend. This is a step towards fix the parser front end so that it
doesn't use encoded permission mappings.

Note: the patch embedds the bool conversion into a struct to ensure
the compiler will fail to build unless every use is fixed. The
struct is removed in the following patch.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 01:05:29 -07:00
John Johansen
fd9a6fe133 parser: int mode to perms
Move from using and int for permissions bit mask to a perms_t type.
Also move any perms mask that uses the name mode to perms to avoid
confusing it with other uses of mode.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-29 10:45:44 -07:00
Georgia Garcia
d98c5c4cf9 parser: add parser support for message queue mediation
Message queue rules take the following format:

	mqueue [<access_mode>] [<type>] [<label>] [<mqueue name>],
	access_mode := 'r'|'w'|'rw'|'read'|'write'|
		       'create'|'open'|'delete'|
		       'getattr'|'setattr'
	type := 'type' '=' ('posix'|'sysv')
	label := 'label' '=' <target label>

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2022-11-22 19:31:15 +00:00
Georgia Garcia
f400b41c4a parser: add support for user namespace creation
Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2022-10-27 17:54:42 +00:00
John Johansen
74bc4275a5 parser: Fix invalid reference to name in attachment warning
The name var is being improperly used in a warning. Not only is
it being used after it is freed, it also never had the correct value
as the "name" variable contained the value being used as the base
attachment.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: time out
2021-04-27 21:06:21 -07:00
John Johansen
be0d2fa947 parser: fix filter slashes for profile attachments
The parser is failing to properly filter the slashes in the profile
attachment after variable expansion. Causing matche failures when
multiple slashes occur.

Fixes: https://gitlab.com/apparmor/apparmor/-/issues/154
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/727
Reported-by: Mikhail Morfikov <mmorfikov@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: time out
2021-04-27 21:06:05 -07:00
John Johansen
2852e1ecdf parser: fix filter slashes for link targets
The parser is failing to properly filter the slashes in the link name
after variable expansion. Causing match failures when multiple slashes
occur.

Fixes: https://gitlab.com/apparmor/apparmor/-/issues/153
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/723
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve.beattie@canonical.com>
2021-03-15 00:45:58 -07:00
Steve Beattie
461d9c2294
treewide: spelling/typo fixes in comments and docs
With the exception of the documentation fixes, these should all be
invisible to users.

Signed-off-by: Steve Beattie <steve.beattie@canonical.com>
Acked-by: Christian Boltz <apparmor@cboltz.de>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/687
2020-12-01 12:47:11 -08:00
John Johansen
6af05006d9 parser: Fix expansion of variables in unix rules addr= conditional
The parser is not treating unix addr as a path and filtering slashes
after variable expansion. This can lead to errors where

@{foo}=/a/
unix bind addr=@{foo}/bar,

will always fail because addr is being matched as /a//bar instead of
/a/bar.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/607
Fixes: https://bugs.launchpad.net/apparmor/+bug/1856738
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-09-29 04:14:35 -07:00
John Johansen
c9d01a325d parser: don't apply exec mapping computations to the policydb
v8 network permissions extend into the range used by exec mapping
so it is important to not blindly do execmapping on both the
file dfa and policydb dfa any more.

Track what type of dfa and its permissions we are building so
we can properly apply exec mapping only when building the
file dfa.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/521
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-09-29 03:34:47 -07:00
John Johansen
e92478a9c5 parser: add support for kernel 4.17 v8 networking
Make it so the parser can properly support network socket mediation
in the upstream kernel,

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/521
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-09-29 03:33:55 -07:00
John Johansen
f5c4927c85 parser: convert remaining pwarn() to flag controlled warns
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>
2020-09-01 19:42:38 -07:00
Mike Salvatore
52d9529d1b parser: replace duplicate warn_once() with common function
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>
2020-08-09 17:56:31 -04:00
John Johansen
c36a5769e6 parser: Change Fall through comment to remove warning
-Wimplicit-fallthrough only recognizes specic comment patterns
switch to a comment it recognizes.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/561
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
2020-06-03 16:29:55 -07:00
John Johansen
a29e232831 parser: feature abi: setup parser to intersect policy and kernel features
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>
2020-05-29 00:23:17 -07:00
John Johansen
444b8e3836 parser: change xattr encoding and allow append_rule to embedd permissions
The current encoding makes every xattr optional and uses this to
propogate the permission from the tail to the individual rule match
points.

This however is wrong. Instead change the encoding so that an xattr
(unless optional) is required to be matched before allowing moving
onto the next xattr match.

The permission is carried on the end on each rule portion file match,
xattr 1, xattr 2, ...

Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
John Johansen
e13af5dc96 parser: fix xattr match encoding so optional xattr is distinct
Make sure we can support optional xattrs distinct from optional xattr
values in the encoding.

Currently all xattrs specified are required to be present even
if there value is not specified. However under the old encoding there
was no way to distinguish if the presence of the xattr vs. the
xattr having a null length value.

Fix this so that if we decide to support optional xattrs it is possible
without having to change the abi.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
John Johansen
e5ea3e4a0d parser: Make xattr attachment generation conditional on kernel support
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
John Johansen
6b47b8de25 parser: Allow xattr globbing to match the NULL character
xattrs are a byte string that can contain all input characters including
the null character. Allow * ** and ? glob patterns to match the null
character while retaining their apparmor characteristics for '/'.

That is * and ? won't traverse a '/' treating it as a path element.
While ** will match anything.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
John Johansen
2992e6973f parser: convert xmatch to use out of band transitions
xattrs can contain NULL characters in their values which means we can
not user regular NULL transitions to separate values. To fix this
use out of band transition instead.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
John Johansen
16b67ddbd6 add ability to use out of band transitions
Currently the NULL character is used as an out of band transition
for string/path elements. This works for them as the NULL character
is not valid for this data. However this does not work for binary
data that can contain a NULL character.

So far we have only dealt with fixed length fields of binary data
making the NULL separator either unnecessary.

However binary data like in the xattr match and mount data field are
variable length and can contain NULL characters. To deal with this
add the ability to specify out of band transitions, that can only
be triggered by code not input data.

The out of band transition can be used to separate variable length
data fields just as the NULL transition has been used to separate
variable length strings.

In the compressed hfa out of band transitions are expressed as a
negative offset from the states base. This leaves us room to expand
the character match range in the future if desired and on average
makes the range between the out of band transition and the input
transitions smaller than would be had if the out of band transition
had been stored after the valid input transitions.

Out of band transitions in the dfa will not break old kernels
that don't know about them, but they won't be able to trigger
the out of band transition match. So they should not be used unless
the kernel indicates that it supports them.

It should be noted that this patch only adds support for a single
out of band transition. If multiple out of band transitions are
required. It is trivial to extend.
- Add a tag indicating support in the kernel
- add a oob max range field to the dfa header so the kernel knows
  what the max range that needs verifying is.
- extend oob generation fns to generate oob based on value instead
  of a fixed -1.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
Eric Chiang
a42fd8c6f4 parser: add support for matching based on extended file attributes
Add userland support for matching based on extended file attributes.
This leverages DFA based matching already in the kernel:

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8e51f908
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=73f488cd

Matching is exposed via flags on the profile:

  /usr/bin/* xattrs=(user.foo=bar user.bar=**) {
      # ...
  }

Profiles list the set of extended attributes that a file MUST have, and
a regex to match the value of that extended attributes. Additional
extended attributes on the file don't effect the match.

Signed-off-by: Eric Chiang <ericchiang@google.com>
2019-03-14 10:47:54 -07:00
Eric Chiang
cc09794fbd parser: determine xmatch priority based on smallest DFA match
The length of a xmatch is used to prioritize multiple profiles that
match the same path, with the intent that the more specific match wins.
Currently, the length of a xmatch is computed by the position of the
first regex character.

While trying to work around issues with no_new_privs by combining
profiles, we noticed that the xmatch length computation doesn't work as
expected for multiple regexs. Consider the following two profiles:

    profile all /** { }
    profile bins /{,usr/,usr/local/}bin/** { }

xmatch_len is currently computed as "1" for both profiles, even though
"bins" is clearly more specific.

When determining the length of a regex, compute the smallest possible
match and use that for xmatch priority instead of the position of the
first regex character.
2019-02-08 13:51:02 -08:00