Commit Graph

3071 Commits

Author SHA1 Message Date
Christian Göttsche
0280a2a70c libselinux: matchmediacon(): close file on error
Found by Infer.

matchmediacon.c:25: error: Resource Leak
  resource of type `_IO_FILE` acquired to `return` by call to `fopen()` at line 21, column 16 is not released after line 25, column 4.
  23. 	while (!feof_unlocked(infile)) {
  24. 		if (!fgets_unlocked(current_line, sizeof(current_line), infile)) {
  25. 			return -1;
         ^
  26. 		}
  27. 		if (current_line[strlen(current_line) - 1])

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
6e5d16a012 libselinux: store_stem(): do not free possible non-heap object
GCC 11 complains:

In file included from label_file.c:24:
In function ‘store_stem’,
    inlined from ‘load_mmap’ at label_file.c:277:12,
    inlined from ‘process_file’ at label_file.c:551:5:
label_file.h:289:25: error: ‘free’ called on pointer ‘*mmap_area.next_addr’ with nonzero offset 4 [-Werror=free-nonheap-object]
  289 |                         free(buf);
      |                         ^~~~~~~~~

Free the pointer on failure at the caller instead of inside `store_stem()`.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
db69a3d362 libselinux: getdefaultcon: free memory on multiple same arguments
Do not leak memory if program arguments get specified more than once.

Found by clang-anlyzer.

getdefaultcon.c:52:3: warning: Potential leak of memory pointed to by 'level' [unix.Malloc]
                fprintf(stderr,
                ^~~~~~~~~~~~~~~
getdefaultcon.c:52:3: warning: Potential leak of memory pointed to by 'role' [unix.Malloc]
                fprintf(stderr,
                ^~~~~~~~~~~~~~~
getdefaultcon.c:52:3: warning: Potential leak of memory pointed to by 'service' [unix.Malloc]
                fprintf(stderr,
                ^~~~~~~~~~~~~~~

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
411c5a5458 libselinux: setexecfilecon(): drop dead assignment
The variable `rc` is always unconditionally assigned by the next call of
`setexeccon()` and never read in between.

Found by clang-analyzer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
04335ab146 libselinux: label_media::init(): drop dead assignment
The variable `lineno` is only used in the preceding loop and it always
set prior that to 0.

Found by clang-analyzer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
9c26043af6 libselinux: label_x::init(): drop dead assignment
The variable `lineno` is only used in the preceding loop and is always
set prior that to 0.

Found by clang-analyzer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
782fa6ea38 libselinux: context_new(): drop dead assignment
The variable `i` is not used inside this loop, and it later
unconditionally set to 0.

Found by clang-analyzer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
319429ba33 libselinux: exclude_non_seclabel_mounts(): drop unused variable
The variable `num` is never read from.

Found by clang-analyer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
d0e16077d4 libselinux: getconlist: free memory on multiple level arguments
Do not leak memory if the program argument `l` got passed more than
once.

Found by clang-analyzer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
d0c02882b7 libselinux: selabel_get_digests_all_partial_matches: free memory after FTS_D block
Free all memory from `selabel_get_digests_all_partial_matches()` in case
of success and failure.

Found by clang-analyzer.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
7464272caa libselinux: selinux_restorecon: mark local variable static
The variable `dir_xattr_list` is only used inside `selinux_restorecon.c`.

selinux_restorecon.c:65:19: warning: no previous extern declaration for non-static variable 'dir_xattr_list' [-Wmissing-variable-declarations]
struct dir_xattr *dir_xattr_list;
                  ^
selinux_restorecon.c:65:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit
struct dir_xattr *dir_xattr_list;
^

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
533e9d6ce0 libselinux: avcstat: use standard length modifier for unsigned long long
The format width specifier `L` is only standardized for floating point
types. Use `ll` for fixed-width data types.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
11194b982b libselinux: sefcontext_compile: mark local variable static
The variable `policy_file` is only used in sefcontext_compile.c.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
7ca82e0db4 libselinux: Sha1Finalise(): do not discard const qualifier
Mark the argument `Buffer` of `Sha1Update()` const, since it is not
modified.

sha1.c: In function ‘Sha1Finalise’:
sha1.c:208:25: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  208 |     Sha1Update(Context, (uint8_t*)"\x80", 1);
      |                         ^
sha1.c:211:29: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  211 |         Sha1Update(Context, (uint8_t*)"\0", 1);
      |                             ^

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
3950b1afed libselinux: label_common(): do not discard const qualifier
As the const qualifier is discarded in label_common(), do not return a
const qualified pointer pointer from the local function `lookup_all()`.

label_file.c: In function ‘lookup_common’:
label_file.c:994:24: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  994 |  struct spec *result = (struct spec*)matches[0];
      |                        ^

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
d23421c65a libselinux: selinux_file_context_cmp(): do not discard const qualifier
matchpathcon.c: In function ‘selinux_file_context_cmp’:
matchpathcon.c:487:18: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  487 |  rest_a = strchr((char *)a, ':');
      |                  ^
matchpathcon.c:488:18: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  488 |  rest_b = strchr((char *)b, ':');
      |                  ^

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Christian Göttsche
ae34b3ca3c libselinux: sidtab_hash(): do not discard const qualifier
Do not discard the const qualifier of the function argument, and drop
the redundant local variable `keyp`.

avc_sidtab.c: In function ‘sidtab_hash’:
avc_sidtab.c:23:9: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   23 |  keyp = (char *)key;
      |         ^

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-18 10:06:22 +02:00
Ondrej Mosnacek
eb6e97ab7d scripts/ci: use F34 image instead of F33
Now that F34 has been released, it's time to update the CI Vagrantfile
to use the new Fedora version. This also fixes the failure in the
recently added vsock_socket test that depends on a bugfix, which made it
to the F34 image's kernel, but is not in the F33 image's.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Petr Lautrbach <plautrba@redhat.com>
2021-05-18 10:05:03 +02:00
James Carter
61fbdce666 libsepol/cil: Check for self-referential loops in sets
The secilc-fuzzer found a self-referential loop using category sets.
Any set declaration in CIL that allows sets in it is susceptible to
the creation of a self-referential loop. There is a check, but only
for the name of the set being declared being used in the set
declaration.

Check for self-refential loops in user, role, and type attributes
and in category sets. Since all of the sets need to be declared,
this check has to be done when verifying the CIL db before doing
the post phase.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-05-13 10:55:34 -04:00
Ondrej Mosnacek
26a4c19ecf fixfiles: do not exclude /dev and /run in -C mode
I can't think of a good reason why they should be excluded. On the
contrary, excluding them can cause trouble very easily if some labeling
rules for these directories change. For example, we changed the label
for /dev/nvme* from nvme_device_t to fixed_disk_device_t in Fedora
(updating the allow rules accordingly) and after policy update they
ended up with an invalid context, causing denials.

Thus, remove /dev and /run from the excludes. While there, also add
/root to the basic excludes to match the regex that excludes fc rules
(that should be effectively no functional change).

I did a sanity check on my system by running `restorecon -nv /dev /run`
and it didn't report any label differences.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Petr Lautrbach <plautrba@redhat.com>
2021-05-12 09:36:16 +02:00
Nicolas Iooss
f1bc162cc2 libselinux: silence -Wstringop-overflow warning from gcc 10.3.1
When building libselinux on Fedora 33 with gcc 10.3.1, the compiler
reports:

    label_file.c: In function ‘lookup_all.isra’:
    label_file.c:940:4: error: ‘strncpy’ specified bound depends on the
    length of the source argument [-Werror=stringop-overflow=]
      940 |    strncpy(clean_key, key, len - 1);
          |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    label_file.c:927:8: note: length computed here
      927 |  len = strlen(key);
          |        ^~~~~~~~~~~
    cc1: all warnings being treated as errors

As clean_key is the result of malloc(len), there is no issue here. But
using strncpy can be considered as strange, because the size of the
string is already known and the NUL terminator is always added later, in
function ‘lookup_all.isra.

Replace strncpy with memcpy to silence this gcc false-positive warning.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
Acked-by: Petr Lautrbach <plautrba@redhat.com>
2021-05-12 09:35:50 +02:00
Christian Göttsche
a88d24522f libselinux: selinux_check_passwd_access_internal(): respect deny_unknown
`selinux_check_passwd_access_internal()`, and thereby
`checkPasswdAccess(3)` and `selinux_check_passwd_access(3)`, does not
respect the policy defined setting of `deny_unknown`, like
`selinux_check_access(3)` does.
This means in case the security class `passwd` is not defined, success
is returned instead of failure, i.e. permission denied.

Most policies should define the `passwd` class and the two affected
public functions are marked deprecated.

Align the behavior with `selinux_check_access(3)` and respect
the deny_unknown setting in case the security class is not defined.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-05-12 09:34:58 +02:00
James Carter
d9433692c7 libsepol/cil: Return an error if a call argument fails to resolve
Return an error if a call argument fails to resolve so that
the resolution phase stops and returns an error.

This problem was found by the secilc-fuzzer.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-05-04 15:55:32 -04:00
James Carter
d438b6cfb3 libsepol/cil: Check datum in ordered list for expected flavor
The secilc-fuzzer found an out of bounds memory access occurs
when building the binary policy if a map class is included in a
classorder statement.

The order statements in CIL (sidorder, classorder, categoryorder,
and sensitivityorder) are used to specify an ordering for sids,
classes, categories, and sensitivities. When the order statments
are resolved and merged, only in the case of the category order
list is the datum resolved checked to see if it is the expected
flavor.

When resolving the sid, class, and sensitivity order statements,
check that each name resolved to a datum of the expected flavor
and return an error if it does not.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-05-04 15:55:12 -04:00
James Carter
74d00a8dec libsepol/cil: Detect degenerate inheritance and exit with an error
A CIL policy with inheritance of the form
...
(blockinherit ba)
(block ba
  (block b1
    (blockinherit bb)
  )
  (block bb
    (block b2
      (blockinherit bc)
    )
    (block bc
      (block b3
        (blockinherit bd)
      )
      (block bd
        (block b4
          (blockinherit be)
        )
        (block be
        ...
will require creating 2^depth copies of the block at the bottom of
the inheritance chain. This pattern can quickly consume all the
memory of the system compiling this policy.

The depth of the inheritance chain can be found be walking the
tree up through the parents and noting how many of the parent
blocks have been inherited. The number of times a block will be
copied is found by counting the list of nodes in the "bi_nodes"
list of the block. To minimize legitimate policies from being
falsely detected as being degenerate, both the depth and breadth
(number of copies) are checked and an error is given only if both
exceed the limits (depth >= 12 and breadth >= 4096).

This problem was found by the secilc-fuzzer.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-05-04 15:55:06 -04:00
James Carter
5681c6275b libsepol/cil: Fix instances where an error returns SEPOL_OK
There are six instances when the CIL policy is being built or
resolved where an error can be detected, but SEPOL_OK is returned
instead of SEPOL_ERR. This causes the policy compiler to continue
when it should exit with an error.

Return SEPOL_ERR in these cases, so the compiler exits with an
error.

Two of the instances were found by the secilc-fuzzer.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-05-04 15:55:00 -04:00
James Carter
2d2c76fc61 libsepol/cil: Properly reset an anonymous classperm set
In struct cil_classperms_set, the "set" field is a pointer to a
struct cil_classpermission. Normally the classpermission is created
in a classpermissionset rule with a name declared in a
classpermission rule and stored in a symbol table. Commit c49a8ea0
("libsepol/cil: cil_reset_classperms_set() should not reset
classpermission") fixed the resetting of classperms sets by setting
the "set" field to NULL rather than resetting the classpermission
that it pointed to.

But this fix mixed the special case where an anonymous classperm
set is passed as an argument to a call. In this case the
classpermission is not named and not stored in a symtab, it is
created just for the classperms set and its classperms list needs
to be reset.

Reset the classperms list if the classperms set is anonymous (which
is when the datum name is NULL).

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-05-04 15:54:36 -04:00
Nicolas Iooss
0744fa4f53
libsepol: use checked arithmetic builtin to perform safe addition
Checking whether an overflow occurred after adding two values can be
achieved using checked arithmetic builtin functions such as:

    bool __builtin_add_overflow(type1 x, type2 y, type3 *sum);

This function is available at least in clang
(at least since clang 3.8.0,
https://releases.llvm.org/3.8.0/tools/clang/docs/LanguageExtensions.html#checked-arithmetic-builtins)
and gcc
(https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html,
since gcc 5 according to https://gcc.gnu.org/gcc-5/changes.html)

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2021-04-30 21:09:36 +02:00
Nicolas Iooss
f63263c2d0
libselinux: do not duplicate make target when going into subdirectory
When running "make install-pywrap", make displays:

    make[1]: Entering directory '/root/selinux/libselinux'
    make -C src install-pywrap install-pywrap
    make[2]: Entering directory '/root/selinux/libselinux/src'

The duplicated "install-pywrap" is not expected. Remove it from the
Makefile.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2021-04-30 21:09:22 +02:00
James Carter
d0a07a7f13
secilc: Create the new program called secil2tree to write out CIL AST
secil2tree is the SELinux CIL AST writer. It calls the cil functions
cil_write_parse_ast(), cil_write_build_ast(), or cil_write_resolve_ast()
to write out the parse tree, the CIL AST after the build phase, or the
CIL AST after the resolve phase.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-21 21:45:31 +02:00
James Carter
86ec04cfde
libsepol/cil: Add functions to make use of cil_write_ast()
Add the functions cil_write_parse_ast(), cil_write_build_ast(),
and cil_write_resolve_ast() that can be used outside of libsepol.

These functions take a FILE pointer and CIL db, do the CIL build
through the desired phase, and then call cil_write_ast() to write
the CIL AST at that point.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-21 21:45:22 +02:00
James Carter
0b31424ac7
libsepol/cil: Create functions to write the CIL AST
The function cil_print_tree() has existed in cil_tree.c since the
beginning of the development of CIL and secilc. Unfortunately, it
used cil_log() at log level CIL_INFO to print out the AST and
has suffered greatly from bit rot.

Move the functions to write the CIL AST to cil_write_ast.c, update
the functions, and write the AST to the FILE pointer passed in as
an argument.

The function cil_write_ast() supports writing the CIL AST at three
different phases of the compiling a CIL policy. After parsing has
been done and the parse tree has been created, after the CIL AST
has been built, and after the CIL AST has been resolved.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-21 21:45:14 +02:00
Ondrej Mosnacek
6cfebe787e
policycoreutils/setfiles: do not create useless setfiles.8.man file
Seems to have been there to allow for some sed substitution over the
text. Now that this is gone, the redundant intermediate file can be
removed, too.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
2021-04-20 09:02:52 +02:00
James Carter
bad0a746e9 secilc/docs: Update the CIL documentation for various blocks
Update the documentation for macros, booleans, booleanifs, tunables,
tunableifs, blocks, blockabstracts, blockinherits, and optionals to
tell where these statements can be used and, for those that have
blocks, what statements are not allowed in them.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:23 -04:00
James Carter
8314076cd9 libsepol/cil: Use CIL_ERR for error messages in cil_compile()
In cil_compile(), CIL_INFO is being used as the priority for
error messages. This can make it difficult to tell when the error
occurred.

Instead, use CIL_ERR as the priority for the error messages in
cil_compile().

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:21 -04:00
James Carter
ca339eb49d libsepol/cil: Make invalid statement error messages consistent
Use a consistent style for the error messages when an invalid
statement is found within tunableif, in-statement, block, macro,
optional, and booleanif blocks.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:20 -04:00
James Carter
ea34dbf041 libsepol/cil: Do not allow tunable declarations in in-statements
Since tunableifs are resolved before in-statements, do not allow
tuanble declarations in in-statements.

Since in-statements are the first flavor of statement that causes
part of the AST to be copied to another part, there is no need to
check the in-statements when resolving the AST.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:18 -04:00
James Carter
f38b7ea300 libsepol/cil: Sync checks for invalid rules in macros
When resolving the AST, tunable and in-statements are not considered
to be invalid in macros. This is inconsistent with the checks when
building the AST.

Add checks to make tunable and in-statments invalid in macros when
resolving the AST.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:16 -04:00
James Carter
340f0eb7f3 libsepol/cil: Check for statements not allowed in optional blocks
While there are some checks for invalid statements in an optional
block when resolving the AST, there are no checks when building the
AST.

OSS-Fuzz found the following policy which caused a null dereference
in cil_tree_get_next_path().
  (blockinherit b3)
  (sid SID)
  (sidorder(SID))
  (optional o
    (ibpkeycon :(1 0)s)
    (block b3
      (filecon""block())
      (filecon""block())))

The problem is that the blockinherit copies block b3 before
the optional block is disabled. When the optional is disabled,
block b3 is deleted along with everything else in the optional.
Later, when filecon statements with the same path are found an
error message is produced and in trying to find out where the block
was copied from, the reference to the deleted block is used. The
error handling code assumes (rightly) that if something was copied
from a block then that block should still exist.

It is clear that in-statements, blocks, and macros cannot be in an
optional, because that allows nodes to be copied from the optional
block to somewhere outside even though the optional could be disabled
later. When optionals are disabled the AST is reset and the
resolution is restarted at the point of resolving macro calls, so
anything resolved before macro calls will never be re-resolved.
This includes tunableifs, in-statements, blockinherits,
blockabstracts, and macro definitions. Tunable declarations also
cannot be in an optional block because they are needed to resolve
tunableifs. It should be fine to allow blockinherit statements in
an optional, because that is copying nodes from outside the optional
to the optional and if the optional is later disabled, everything
will be deleted anyway.

Check and quit with an error if a tunable declaration, in-statement,
block, blockabstract, or macro definition is found within an
optional when either building or resolving the AST.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:14 -04:00
James Carter
8a74c05b97 libsepol/cil: Sync checks for invalid rules in booleanifs
When building the AST, typemember rules in a booleanif block will
be incorrectly called invalid. They are allowed in the kernel
policy and should be allowed in CIL.

When resolving the AST, if a neverallow rule is copied into a
booleanif block, it will not be considered an invalid rule, even
though this is not allowed in the kernel policy.

Update the booleanif checks to allow typemember rules and to not
allow neverallow rules in booleanifs. Also use the same form of
conditional for the checks when building and resolving the AST.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:13 -04:00
James Carter
ef533c8fd9 libsepol/cil: Reorder checks for invalid rules when resolving AST
Reorder checks for invalid rules in the blocks of tunableifs,
in-statements, macros, and booleanifs when resolving the AST for
consistency.

Order the checks in the same order the blocks will be resolved in,
so tuanbleif, in-statement, macro, booleanif, and then non-block
rules.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:11 -04:00
James Carter
525f0312d5 libsepol/cil: Use AST to track blocks and optionals when resolving
When resolving the AST, block and optional stacks are used to
determine if the current rule being resolved is in a block or
an optional. There is no need to do this since the parent node
pointers can be used when exiting a block or an optional to
determine if resolution is still within a block or an optional.

When entering either a block or an optional, update the appropriate
tree node pointer. When finished with the last child of a block or
optional, set the appropriate pointer to NULL. If a parent of the
same kind is found when the parent node pointers are followed back
to the root node, then set the pointer to that tree node.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:09 -04:00
James Carter
ab90cb46ab libsepol/cil: Create new first child helper function for building AST
In order to find statements not allowed in tunableifs, in-statements,
macros, and booleanifs, there are tree node pointers that point to
each of these kinds of statements when its block is being parsed.
If the pointer is non-NULL, then the rule being parsed is in the block
of that kind of statement.

The tree node pointers were being updated at the wrong point which
prevented an invalid statement from being found if it was the first
statement in the block of a tunableif, in-statement, macro, or
booleanif.

Create a first child helper function for walking the parse tree and
in that function set the appropriate tree node pointer if the
current AST node is a tunableif, in-statement, macro, or booleanif.
This also makes the code symmetrical with the last child helper
where the tree node pointers are set to NULL.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:07 -04:00
James Carter
f043078f1d libsepol/cil: Cleanup build AST helper functions
Since parse_current, finished, and extra_args can never be NULL,
remove the useless check and directly assign local variables from
extra_args.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:05 -04:00
James Carter
69bfe64cdf libsepol/cil: Reorder checks for invalid rules when building AST
Reorder checks for invalid rules in the blocks of tunableifs,
in-statements, macros, and booleanifs when building the AST for
consistency.

Order the checks in the same order the blocks will be resolved in,
so tuanbleif, in-statement, macro, booleanif, and then non-block
rules.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 14:05:03 -04:00
James Carter
e65cf030b7 libsepol/cil: Move check for the shadowing of macro parameters
In cil_gen_node(), after the declaration is added to the symbol
table, if the parent is a macro, then a check is made to ensure
the declaration does not shadow any of the macro's parameters.
This check also needs to be done when copying the AST.

Move the check for the shadowing of macro parameters to its own
function, cil_verify_decl_does_not_shadow_macro_parameter(), and
refactor cil_gen_node() and __cil_copy_node_helper() to use the
new function.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 10:40:54 -04:00
James Carter
0d4e568afe libsepol/cil: Create function cil_add_decl_to_symtab() and refactor
The functionality of adding a declaration to a symbol table is also
needed in __cil_copy_node_helper() and not just cil_gen_node().

Create a new function called cil_add_decl_to_symtab() to add a
declaration to a symtab and refactor cil_gen_node() and
__cil_copy_node_helper() to use the new function.

By using the new function, __cil_copy_node_helper() will now allow
duplicate declarations when appropriate.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 10:40:52 -04:00
James Carter
63ce05ba07 libsepol/cil: Refactor helper function for cil_gen_node()
Change the name of cil_is_datum_multiple_decl() to
cil_allow_multiple_decls() and make it static. The new function
takes the CIL db and the flavors of the old and new datum as
arguments. Also, put all of the logic of determining if multiple
declarations are allowed into the new function. Finally, update
the call from cil_gen_node().

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 10:40:49 -04:00
James Carter
22fb6f477b libsepol/cil: Allow permission expressions when using map classes
The following policy will cause a segfault:
  (class CLASS (PERM))
  (class C (P1 P2 P3))
  (classorder (CLASS C))
  (sid SID)
  (sidorder (SID))
  (user USER)
  (role ROLE)
  (type TYPE)
  (category CAT)
  (categoryorder (CAT))
  (sensitivity SENS)
  (sensitivityorder (SENS))
  (sensitivitycategory SENS (CAT))
  (allow TYPE self (CLASS (PERM)))
  (roletype ROLE TYPE)
  (userrole USER ROLE)
  (userlevel USER (SENS))
  (userrange USER ((SENS)(SENS (CAT))))
  (sidcontext SID (USER ROLE TYPE ((SENS)(SENS))))

  (classmap CM (PM1 PM2 PM3))
  (classmapping CM PM1 (C (P1)))
  (classmapping CM PM2 (C (P2)))
  (classmapping CM PM3 (C (P3)))
  (allow TYPE self (CM (and (all) (not PM2))))

The problem is that, while permission expressions are allowed for
normal classes, map classes are expected to only have permission
lists and no check is done to verify that only a permission list
is being used.

When the above policy is parsed, the "and" and "all" are seen as
expression operators, but when the map permissions are converted to
normal class and permissions, the permission expression is assumed
to be a list of datums and since the operators are not datums a
segfault is the result.

There is no reason to limit map classes to only using a list of
permissions and, in fact, it would be better to be able to use them
in the same way normal classes are used.

Allow permissions expressions to be used for map classes by first
evaluating the permission expression and then converting the
resulting list to normal classes and permissions.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 10:40:46 -04:00
James Carter
532469a251 libsepol/cil: Exit with an error if declaration name is a reserved word
When CIL parses sets or conditional expressions, any identifier that
matches an operator name will always be taken as an operator. If a
declaration has the same name as an operator, then there is the
possibility of causing either confusion or a syntax error if it is
used in an expression. The potential for problems is much greater
than any possible advantage in allowing a declaration to share the
name of a reserved word.

Create a new function, __cil_is_reserved_name() that is called when
an identifier is declared and its name is being validated. In this
function, check if the declaration has the same name as a reserved
word for an expression operator that can be used with the identifer's
flavor and exit with an error if it does.

Also, move the check for types, type aliases, and type attributes
matching the reserved word "self" to this new function.

Finally, change the name of the function __cil_verify_name() to
cil_verify_name(), since this function is neither static nor a
helper function.

Signed-off-by: James Carter <jwcart2@gmail.com>
2021-04-19 10:40:43 -04:00