selinux/libsepol
Nicolas Iooss b320291888 libsepol/cil: fix memory leak when a constraint expression is too deep
When __cil_validate_constrain_expr() fails,
cil_constrain_to_policydb_helper() does not destroy the constraint
expression. This leads to a memory leak reported by OSS-Fuzz with the
following CIL 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))))

    (constrain
        (CLASS (PERM))
        (or
            (eq t1 TYPE)
            (or
                (eq t1 TYPE)
                (or
                    (eq t1 TYPE)
                    (or
                        (eq t1 TYPE)
                        (or
                            (eq t1 TYPE)
                            (eq t1 TYPE)
                        )
                    )
                )
            )
        )
    )

Add constraint_expr_destroy(sepol_expr) to destroy the expression.

Moreover constraint_expr_destroy() was not freeing all items of an
expression. Code in libsepol/src and checkpolicy contained while loop to
free all the items of a constraint expression, but not the one in
libsepol/cil. As freeing only the first item of an expression is
misleading, change the semantic of constraint_expr_destroy() to iterate
the list of constraint_expr_t and to free all items.

Fixes: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28938
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
Acked-by: James Carter <jwcart2@gmail.com>
2021-02-03 09:28:39 +01:00
..
cil libsepol/cil: fix memory leak when a constraint expression is too deep 2021-02-03 09:28:39 +01:00
include libsepol: Drop deprecated functions 2020-10-19 22:11:39 +02:00
man selinux: Update manpages after removing legacy boolean and user code 2019-07-29 23:46:47 +02:00
src libsepol/cil: fix memory leak when a constraint expression is too deep 2021-02-03 09:28:39 +01:00
tests libsepol/tests: drop ncurses dependency 2020-05-04 10:31:44 +02:00
utils libsepol: build: follow standard semantics for DESTDIR and PREFIX 2018-02-14 15:59:36 +01:00
.gitignore
COPYING
Makefile
VERSION Update VERSIONs and Python bindings version to 3.2-rc1 for release 2021-01-20 12:40:14 +01:00