Commit Graph

432 Commits

Author SHA1 Message Date
Daniel Jurgens
28663ff135 libsepol: Add IB end port handling to CIL
Add IB end port parsing, symbol table management, and policy generation
to CIL.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
2017-05-23 16:20:55 -04:00
Daniel Jurgens
118c0cd103 libsepol: Add ibendport ocontext handling
Add support for reading, writing, and copying IB end port ocontext data.
Also add support for querying a IB end port sid to checkpolicy.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
2017-05-23 16:20:55 -04:00
Daniel Jurgens
5bc05dd2a5 checkpolicy: Add support for ibendportcon labels
Add checkpolicy support for scanning and parsing ibendportcon labels.
Also create a new ocontext for IB end ports.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
2017-05-23 16:20:55 -04:00
Daniel Jurgens
e564f7b5bd libsepol: Add Infiniband Pkey handling to CIL
Add Infiniband pkey parsing, symbol table management, and policy
generation to CIL.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
2017-05-23 16:20:54 -04:00
Daniel Jurgens
9fbb311276 libsepol: Add ibpkey ocontext handling
Add support for reading, writing, and copying Infiniband Pkey ocontext
data. Also add support for querying a Pkey sid to checkpolicy.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
2017-05-23 16:20:54 -04:00
Daniel Jurgens
5b203145fd checkpolicy: Add support for ibpkeycon labels
Add checkpolicy support for scanning and parsing ibpkeycon labels. Also
create a new ocontext for Infiniband Pkeys and define a new policydb
version for infiniband support.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
2017-05-23 16:20:54 -04:00
Nicolas Iooss
bfd61a3ec7 libsepol: use the number of elements in calloc first argument
When allocating an array with calloc(), the first argument usually is
the number of items and the second one the size of an item. Doing so
silences a warning reported by clang's static analyzer:

    kernel_to_cil.c:2050:14: warning: Call to 'calloc' has an allocation
    size of 0 bytes.
            cond_data = calloc(sizeof(struct cond_data), num);
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-05-23 15:56:31 -04:00
Nicolas Iooss
d00cc13483 libsepol: propagate calloc() failure
When common_to_cil() or class_to_cil() fail to allocate an array to map
a permissions hashtable (for example when permissions.nprim is too big),
class_perm_to_array() gets called on a NULL pointer. Fix this.

This issue has been found while fuzzing hll/pp with the American Fuzzy
Lop.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-05-23 15:55:02 -04:00
Nicolas Iooss
8fe362f012 libsepol: remove unused attribute on a used argument
Since commit 58962eb3d8 ("libsepol,checkpolicy: add binary module
support for xperms") function avrule_read() has been using its "p"
argument even though it was previously marked unused. This makes clang
report:

    policydb.c:3276:7: error: 'p' was marked unused but was used
    [-Werror,-Wused-but-marked-unused].
        if (p->policyvers < MOD_POLICYDB_VERSION_XPERMS_IOCTL) {
            ^

Remove the attribute to make the code consistent again.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-05-18 08:54:42 -04:00
Stephen Smalley
58962eb3d8 libsepol,checkpolicy: add binary module support for xperms
Presently we support xperms rules in source policy and in CIL modules.
The binary policy module format however was never extended for xperms.
This limitation inhibits use of xperms in refpolicy-based policy modules
(including the selinux-testsuite policy).  Update libsepol to support
linking, reading, and writing a new binary policy module version that
supports xperms rules.  Update dismod to display xperms rules in binary
policy modules.

Also, to support use of a non-base binary policy module with a newer
version on a system using a base policy module with an older version,
automatically upgrade the version during module linking.  This facilitates
usage of newer features in non-base modules without requiring rebuilding
the base module.

Tests:
1. Add an allowxperms rule to the selinux-testsuite policy and
confirm that it is properly written to the binary policy module
(displayed by dismod), converted to CIL (the latter was already supported),
and included in the kernel policy (via dispol and kernel test).

2. Use semodule_link and semodule_expand to manually link and expand
all of the .pp files via libsepol, and confirm that the allowxperms rule
is correctly propagated to the kernel policy.  This test is required to
exercise the legacy link/expand code path for binary modules that predated
CIL.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
2017-05-17 09:35:52 -04:00
Nicolas Iooss
4a0fab43cb libsepol/cil: do not use an uninitialized value in __cil_fqn_qualify_blocks
In __cil_fqn_qualify_blocks(), when newlen >= CIL_MAX_NAME_LENGTH,
cil_tree_log() is called with child_args.node as argument but this value
has not been initialized yet. Use local variable node instead, which is
initialized early enough in the function.

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-05-15 16:36:49 -04:00
Stephen Smalley
c3118041df checkpolicy,libsepol: drop unnecessary usage of s6_addr32
s6_addr32 is not portable; use s6_addr instead.
This obviates the need for #ifdef __APPLE__ conditionals in these cases.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
2017-05-10 10:25:56 -04:00
Jeff Vander Stoep
1089665e31 Add attribute expansion options
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.

Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)

Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)

Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.

Motivation

expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.

Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]

expandattribute false:
Commit 0be23c3f15 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.

[1] https://github.com/SELinuxProject/cil/issues/9
[2] Annotating all HAL client attributes for expansion resulted in
    system_server's dropping from 19 attributes to 8. Because these
    attributes were not widely applied to other types, the final
    policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
    policy when using secilc's -G option. This impacts 11 neverallow
    tests in CTS.

Test: Build and boot Marlin with all hal_*_client attributes marked
    for expansion. Verify (using seinfo and sesearch) that permissions
    are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
    that they are retained in policy and applied to the same types.

Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
2017-05-09 12:09:46 -04:00
Petr Lautrbach
4d7dee28f4 libsepol/utils: Fix build without system sepol.h
fcb5d5c removed ../include from CFLAGS from libsepol/utils/Makefile so
that a build tool can't find sepol/sepol.h when only libsepol is built
and a system is without sepol.h in standard paths. It should use its own
sepol.h file during build. `oveeride` needs to be used in order not to
be overridden by values provided on a command line. Same problem applies
to LDFLAGS.

Fixes:
$ make CFLAGS="" LDFLAGS=""
make[1]: Entering directory '/root/selinux/libsepol/utils'
cc     chkcon.c  -lsepol -o chkcon
chkcon.c:1:25: fatal error: sepol/sepol.h: No such file or directory
 #include <sepol/sepol.h>

$ make CFLAGS="" LDFLAGS=""
...
make -C utils
make[1]: Entering directory '/root/selinux/libsepol/utils'
cc  -I../include    chkcon.c  -lsepol -o chkcon
/usr/bin/ld: cannot find -lsepol
collect2: error: ld returned 1 exit status

Signed-off-by: Petr Lautrbach <plautrba@redhat.com>
2017-05-05 15:48:22 -04:00
Nicolas Iooss
1dc95dd558 libsepol: silence false-positive -Wwrite-strings warning
When compiling with -Wwrite-strings, the compiler complains about
calling strs_add with a const char* value for a char* parameter
(DEFAULT_OBJECT is defined to "object_r"). Silence this warning by
casting the literal string to char*.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-05-05 13:09:36 -04:00
Jason Zaman
fcb5d5cc72 Makefiles: drop -L/-I to system paths
The toolchain automatically handles them and they break cross compiling.

LDFLAGS should also come before object files, some flags (eg,
-Wl,as-needed) can break things if they are in the wrong place)

Gentoo-Bug: https://bugs.gentoo.org/500674

Signed-off-by: Jason Zaman <jason@perfinion.com>
2017-04-25 08:27:05 -04:00
Nicolas Iooss
b63eb892f9 libsepol: cil: check cil_fill_list return value
cil_gen_default() and cil_gen_defaultrange() call cil_fill_list()
without checking its return value. If it failed, propagate the return
value to the caller.

This issue has been found using clang's static analyzer. It reported
"warning: Value stored to 'rc' is never read" four times.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-04-12 14:40:16 -04:00
James Carter
0be23c3f15 libsepol/cil: Add ability to expand some attributes in binary policy
Originally, all type attributes were expanded when building a binary
policy. As the policy grew, binary policy sizes became too large, so
changes were made to keep attributes in the binary policy to minimize
policy size.

Keeping attributes works well as long as each type does not have too
many attributes. If an access check fails for types t1 and t2, then
additional checks must be made for every attribute that t1 is a member
of against t2 and all the attributes that t2 is a member of. This is
O(n*m) behavior and there are cases now where this is becoming a
performance issue.

Attributes are more aggressively removed than before. An attribute
will now be removed if it only appears in rules where attributes are
always expanded (typetransition, typechange, typemember, roletransition,
rangetransition, roletype, and AV Rules with self).

Attributes that are used in constraints are always kept because the
attribute name is stored for debugging purposes in the binary policy.

Attributes that are used in neverallow rules, but not in other AV rules,
will be kept unless the attribute is auto-generated.

Attributes that are only used in AV rules other than neverallow rules
are kept unless the number of types assigned to them is less than the
value of attrs_expand_size in the CIL db. The default is 1, which means
that any attribute that has no types assigned to it will be expanded (and
the rule removed from the policy), which is CIL's current behavior. The
value can be set using the function cil_set_attrs_expand_size().

Auto-generated attributes that are used only in neverallow rules are
always expanded. The rest are kept by default, but if the value of
attrs_expand_generated in the CIL db is set to true, they will be
expanded. The function cil_set_attrs_expand_generated() can be used
to set the value.

When creating the binary policy, CIL will expand all attributes that
are being removed and it will expand all attributes with less members
than the value specified by attrs_expand_size. So even if an attribute
is used in a constraint or neverallow and the attribute itself will be
included in the binary policy, it will be expanded when writing AV
rules if it has less members than attrs_expand_size.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-04-12 14:33:49 -04:00
Nicolas Iooss
473753f21a libsepol: correct spelling errors in module_to_cil.c comments
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-04-12 14:21:32 -04:00
Nicolas Iooss
d88657bc4d libsepol: do not leak memory when an error occurs
name_list_to_string() and constraint_expr_to_string() both define an
exit label to clean-up dynamically-allocated memory when an error
occurs, but they miss some variables. Free the missing ones too.

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-04-12 14:20:30 -04:00
Nicolas Iooss
8ccd0db860 libsepol: do not free attr_name twice
When set_to_names() fails to allocate *names, it frees variable
attr_name even though it either came from attr_list or was newly created
and added to attr_list. By doing so, the name is freed a second time
when attr_list is destroyed (with "attr_list_destroy(&attr_list)").

Avoid this double free by not freeing attr_name when it belongs to
attr_list.

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-04-12 14:18:35 -04:00
Nicolas Iooss
3e7fd1daba libsepol: do not wrap integers when checking bound
Some invalid policies might have p->p_types.nprim = 0. When parsing
such a policy, "i > p->p_types.nprim - 1" is always false even though
reading p->type_val_to_struct[i] triggers a segmentation fault.

Make type_set_expand() return an error when parsing such a policy by
handling correctly when p->p_types.nprim is zero.

This issue has been found while fuzzing semodule_package with the
American Fuzzy Lop.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-04-11 14:33:48 -04:00
Nicolas Iooss
42e32227da libsepol: refuse to load policies with no block
Some functions assumes that p->global is not NULL. For example
range_read() contains:

    p->global->enabled->range_tr_rules = rtr;

However p->global may currently be NULL when loading a policy module
with no avrule block. Avoid a NULL pointer dereference by making such a
policy invalid.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-04-11 14:33:04 -04:00
Stephen Smalley
e6edc42455 libsepol: do not seg fault on sepol_*_key_free(NULL)
sepol_*_key_free(NULL) should just be a no-op just like
free(NULL).  Fix several instances that did not handle this
correctly and would seg fault if called with NULL.

Test: setsebool -P zebra_write_config=1 while non-root

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
2017-04-07 11:04:43 -04:00
James Carter
92f22e193a libsepol: In module_to_cil create one attribute for each unique set
CIL does not allow type or role sets in certain rules (such as allow
rules). It does, however, allow sets in typeattributeset and
roleattributeset statements. Because of this, when module_to_cil
translates a policy into CIL, it creates a new attribute for each
set that it encounters. But often the same set is used multiple times
which means that more attributes are created then necessary. As the
number of attributes increases the time required for the kernel to
make each policy decision increases which can be a problem.

To help reduce the number of attributes in a kernel policy,
when module_to_cil encounters a role or type set search to see if the
set was encountered already and, if it was, use the previously
generated attribute instead of creating a new one.

Testing on Android and Refpolicy policies show that this reduces the
number of attributes generated by about 40%.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-04-05 12:24:05 -04:00
James Carter
0a08fd1e69 libsepol: Add ability to convert binary policy to policy.conf file
It would sometimes be helpful for debugging or verification purposes
to be able to convert a binary policy to a human-readable form.

Create new function, sepol_kernel_policydb_to_conf(), that takes a
policydb created from a binary policy and writes a policy.conf file
to the provided FILE pointer.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-04-05 12:23:25 -04:00
James Carter
70a480bfcd libsepol: Add ability to convert binary policy to CIL
It would sometimes be helpful for debugging or verification purposes
to be able to convert a binary policy to a human-readable form.

Create new function, sepol_kernel_policydb_to_cil(), that takes a
policydb created from a binary policy and writes CIL policy to the
provided FILE pointer.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-04-05 12:23:05 -04:00
Nicolas Iooss
b251dbba98 libsepol: fix use-after-free in sepol_user_clone()
When sepol_user_add_role() fails to allocate memory for role_cp but
succeeds in reallocating user->roles memory, it frees this reallocated
memory, thus leaving user->roles referencing a free memory block. When
sepol_user_clone() calls sepol_user_free(new_user) because the
allocation failure made sepol_user_add_role() fail, the following code
is executed:

    for (i = 0; i < user->num_roles; i++)
        free(user->roles[i]);
    free(user->roles);

As user->roles has been freed, this code frees pointers which may be
invalid and then tries to free user->roles again.

Fix this flaw by returning right after strdup() failed in
sepol_user_add_role().

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-29 10:26:47 -04:00
Nicolas Iooss
b6579d262e libsepol: constify sepol_genbools()'s boolpath parameter
This allows removing an unnecessary cast to (char *) in libselinux.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-29 10:26:44 -04:00
Nicolas Iooss
76f8c04c19 libsepol: make process_boolean() fail on invalid lines
When load_booleans() calls process_boolean() to parse a boolean
definition, process_boolean() returns a successful value when it fails
to use strtok_r() (e.g. when there is no "=" in the parsed line). This
leads load_booleans() to use uninitialized name and/or val when setting
the boolean into the policy.

Rework process_boolean() in order to report errors when a boolean
definition is incorrect.

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-29 10:26:40 -04:00
Nicolas Iooss
a83f1cfd7e libsepol: do not dereference a NULL pointer when stack_init() fails
In cond_expr_to_cil() when stack_init(&stack) fails, stack is set to
NULL and the execution flow jumps to label "exit". This triggers a call
to stack_pop(stack) which dereferences a NULL pointer in "if (stack->pos
== -1)".

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-29 10:26:35 -04:00
Nicolas Iooss
6e3c3595b1 libsepol/cil: do not dereference a NULL pointer when calloc() fails
When list_init() fails to allocate a list with calloc(), it calls
list_destroy(&l) with l = NULL. This functions starts by dereferencing
its argument ("(*list)->head"), which does not work well when it is
NULL.

This bug can be fixed by returning directly in list_init() when calloc()
fails. Doing so allows making list_init() implementation shorter by
removing label "exit" and local variable "rc".

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-28 13:40:56 -04:00
James Carter
af0ce03ec7 libsepol/cil: Add hexadecimal support for Xen ioportcon statements
Add hexadecimal support for Xen ioportcon statements which was
left out of commit c408c70.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-03-28 13:33:05 -04:00
James Carter
da2f2316a3 libsepol/cil: Use hexadecimal numbers when writing Xen rules
When writing a policy.conf file from CIL source, use hexadecimal
numbers in ioportcon, iomemcon, and pcidevicecon rules.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-03-21 14:22:42 -04:00
James Carter
526d0dadb8 libsepol: Update module_to_cil to output hexadecimal for Xen rules
When generating CIL, use hexadecimal numbers in ioportcon,
iomemcon, and pcidevicecon statements.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-03-21 14:22:38 -04:00
James Carter
c408c70b0a libsepol/cil: Allow hexadecimal numbers in Xen context rules
Allow the use of hexadecimal numbers in iomemcon, ioportcon, and
pcidevicecon statements. The use of hexadecimal numbers is often
the natural choice for these rules.

A zero base is now passed to strtol() and strtoull() which will
assume base 16 if the string has a prefix of "0x", base 8 if the
string starts with "0", and base 10 otherwise.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-03-21 14:22:34 -04:00
Nicolas Iooss
6707526f1f libsepol/cil: avoid freeing uninitialized values
cil_resolve_ast() begins by checking whether one of its parameters is
NULL and "goto exit;" when it is the case. As extra_args has not been
initialized there, this leads to calling cil_destroy_tree_node_stack(),
__cil_ordered_lists_destroy()... on garbage values.

In practise this cannot happen because cil_resolve_ast() is only called
by cil_compile() after cil_build_ast() succeeded. As the if condition
exists nonetheless, fix the body of the if block in order to silence a
warning reported by clang Static Analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-21 14:20:22 -04:00
Nicolas Iooss
0864814583 libsepol/cil: make reporting conflicting type transitions work
When compiling a CIL policy which defines conflicting type transitions,
secilc crashes when trying to format an error message with uninitialized
values. This is caused by __cil_typetransition_to_avtab() not
initializing the ..._str fields of its local variable "struct
cil_type_rule trans" before calling __cil_type_rule_to_avtab().

While at it, make the error report clearer about what is wrong by
showing the types and classes which got expanded in
__cil_type_rule_to_avtab(). Here is an example of the result:

    Conflicting type rules (scontext=testuser_emacs.subj
    tcontext=fs.tmpfs.fs tclass=dir
    result=users.generic_tmpfs.user_tmpfs_file),
    existing=emacs.tmpfs.user_tmpfs_file

    Expanded from type rule (scontext=ARG1 tcontext=fs tclass=ARG3
    result=ARG2)

Reported-By: Dominick Grift <dac.override@gmail.com>
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-21 14:20:17 -04:00
Stephen Smalley
43b24f0132 libsepol: Define cgroup_seclabel policy capability
Define the new cgroup_seclabel policy capability used to
enable userspace setting of security labels on cgroup files
via setfscreatecon() aka /proc/self/attr/fscreate and/or
setfilecon() aka setxattr().

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
2017-03-02 12:39:13 -05:00
Nicolas Iooss
ddaf0afec7 libsepol/cil: do not dereference args before checking it was not null
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-03-01 10:42:23 -05:00
James Carter
a2d40aaeba libsepol/cil: Move initialization of bitmap in __cil_permx_to_bitmap()
Nicolas Iooss reports:
  When __cil_permx_to_bitmap() calls __cil_permx_str_to_int() on an
  invalid number, local variablt "bitmap" is left initialized when
  the function returns and its memory is leaked.

  This memory leak has been found by running clang's Address Sanitizer
  on a set of policies generated by American Fuzzy Lop.

Move the initialization of bitmap to right before ebitmap_set_bit()
and after the call to __cil_permx_str_to_int().

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-02-21 13:11:15 -05:00
Nicolas Iooss
95e5c103f3 libsepol/cil: free bitmaps in cil_level_equals()
cil_level_equals() builds two bitmap and compare them but does not
destroy them before returning the result.

This memory leak has been found by running clang's Address Sanitizer on
a set of policies generated by American Fuzzy Lop.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-02-21 13:09:49 -05:00
Nicolas Iooss
9feaf0380d libsepol/cil: do not leak left-hand side of an invalid constraint
__cil_fill_constraint_expr() does not destroy the list associated with
the first operand of a two-operand operation when the second operand is
invalid.

This memory leak can be reproduced with the following policy:

    (constrain (files (read))
        (not (or (and (eq t1 exec_t) (%q t2 bin_t)) (eq r1 r2))))

This memory leak has been found by running clang's Address Sanitizer on
a set of policies generated from secilc/test/policy.cil by American
Fuzzy Lop.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-02-21 13:09:44 -05:00
Nicolas Iooss
602385d70c libsepol/cil: free the first operand if the second one is invalid
When __cil_expr_to_bitmap() fails to parse the second operand of an
operation with two operands, it returns an error without destroying the
bitmap which has been created for the first operand. Fix this memory
leak.

This has been tested with the following policy:

    (class CLASS (PERM))
    (classorder (CLASS))
    (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))))

    (permissionx ioctl_test (ioctl CLASS
        (and (range 0x1600 0x19FF) (.ot (range 0x1750 0x175F)))))

This memory leak has been found by running clang's Address Sanitizer on
a set of policies generated from secilc/test/policy.cil by American
Fuzzy Lop.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-02-21 13:09:39 -05:00
Nicolas Iooss
7fe9a7be31 libsepol/cil: use __cil_ordered_lists_destroy() to free unordered_classorder_lists
In cil_resolve_ast, unordered_classorder_lists is a list of
cil_ordered_list. It needs to be destroyed with
__cil_ordered_lists_destroy() to free all associated memory.

This has been tested with the following policy:

    (class CLASS1 ())
    (class CLASS2 ())
    (classorder (unordered CLASS1))
    (classorder (CLASS2))

This memory leak has been found by running clang's Address Sanitizer on
a set of policies generated by American Fuzzy Lop.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-02-21 13:09:22 -05:00
James Carter
9edcf28a04 libsepol/cil: Destroy cil_tree_node stacks when finished resolving AST
CIL uses separate cil_tree_node stacks for optionals and blocks to
check for statements not allowed in optionals or blocks and to know
which optional to disable when necessary. But these stacks were not
being destroyed when exiting cil_resolve_ast(). This is not a problem
normally because the stacks will be empty, but this is not the case
when exiting with an error.

Destroy both tree node stacks when exiting to ensure that they are
empty.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-02-17 10:53:52 -05:00
Nicolas Iooss
eeafde1351 libsepol/cil: fix type confusion in cil_copy_ast
When running secilc on the following CIL file, the program tries to free
the data associated with type X using cil_destroy_typeattribute():

    (macro sys_obj_type ((user ARG1)) (typeattribute X))

    (block B
        (type X)
        (call sys_obj_type (Y))
    )

By adding some printf statements to cil_typeattribute_init(),
cil_type_init() and cil_destroy_typeattribute(), the error message I get
when using gcc's address sanitizer is:

$ secilc -o /dev/null -f /dev/null test.cil -vvvvvv
creating TYPE 0x60400000dfd0
Parsing 2017-02-02_crashing_nulptrderef_cil.cil
Building AST from Parse Tree
creating TYPEATTR 0x60600000e420
creating TYPE 0x60400000df50
Destroying Parse Tree
Resolving AST
Failed to resolve call statement at 2017-02-02_crashing_nulptrderef_cil.cil:5
Problem at 2017-02-02_crashing_nulptrderef_cil.cil:5
Pass 8 of resolution failed
Failed to resolve ast
Failed to compile cildb: -2
Destroying TYPEATTR 0x60600000e420, types (nil) name X
Destroying TYPEATTR 0x60400000df50, types 0xbebebebe00000000 name X
ASAN:DEADLYSIGNAL
=================================================================
==30684==ERROR: AddressSanitizer: SEGV on unknown address
0x000000000000 (pc 0x7fc0539d114a bp 0x7ffc1fbcb300 sp
0x7ffc1fbcb2f0 T0)
    #0 0x7fc0539d1149 in ebitmap_destroy /usr/src/selinux/libsepol/src/ebitmap.c:356
    #1 0x7fc053b96201 in cil_destroy_typeattribute ../cil/src/cil_build_ast.c:2370
    #2 0x7fc053b42ea4 in cil_destroy_data ../cil/src/cil.c:616
    #3 0x7fc053c595bf in cil_tree_node_destroy ../cil/src/cil_tree.c:235
    #4 0x7fc053c59819 in cil_tree_children_destroy ../cil/src/cil_tree.c:201
    #5 0x7fc053c59958 in cil_tree_subtree_destroy ../cil/src/cil_tree.c:172
    #6 0x7fc053c59a27 in cil_tree_destroy ../cil/src/cil_tree.c:165
    #7 0x7fc053b44fd7 in cil_db_destroy ../cil/src/cil.c:299
    #8 0x4026a1 in main /usr/src/selinux/secilc/secilc.c:335
    #9 0x7fc0535e5290 in __libc_start_main (/usr/lib/libc.so.6+0x20290)
    #10 0x403af9 in _start (/usr/src/selinux/DESTDIR/usr/bin/secilc+0x403af9)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /usr/src/selinux/libsepol/src/ebitmap.c:356 in ebitmap_destroy
==30684==ABORTING

When copying the AST tree in cil_resolve_call1(),
__cil_copy_node_helper() calls cil_copy_typeattribute() to grab type X
in the symbol table of block B, and creates a node with the data of X
but with CIL_TYPEATTRIBUTE flavor.

This example is a "type confusion" bug between cil_type and
cil_typeattribute structures. It can be generalized to any couple of
structures sharing the same symbol table (an easy way of finding other
couples is by reading the code of cil_flavor_to_symtab_index()).

Fix this issue in a "generic" way in __cil_copy_node_helper(), by
verifying that the flavor of the found data is the same as expected and
triggering an error when it is not.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-02-08 10:48:40 -05:00
Nicolas Iooss
c33fd02db5 libsepol/tests: fix -Wwrite-strings warnings
Since fd9e5ef7b7 ("libsepol: use constant keys in hashtab functions")
it is possible to call hashtab_search() with a const char* key value.
Doing so fixes compiler warnings about non-const char* string literals
(-Wwrite-strings flag).

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-02-06 11:06:04 -05:00
Nicolas Iooss
d6b5b037f9 libsepol: fix -Wwrite-strings warnings
When compiling with -Wwrite-strings, clang reports some warnings like:

    module_to_cil.c:784:13: error: assigning to 'char *' from 'const
    char [5]' discards qualifiers
    [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
                    statement = "type";
                              ^ ~~~~~~
    module_to_cil.c:787:13: error: assigning to 'char *' from 'const
    char [5]' discards qualifiers
    [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
                    statement = "role";
                              ^ ~~~~~~

Add a const type attribute to local variables which only handle constant
strings.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2017-02-06 11:05:33 -05:00
James Carter
8adbd615c1 libsepol: Return +1 when declaration is followed by a require
A check is made in symtab_insert() for the case when an identifier
had already been declared and was now being required. This meant
that a declaration followed by a require was treated differently
from a require followed by a declaration.

Remove that check and treat both cases the same (which means
returning +1).

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
2017-02-03 14:02:32 -05:00