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>
1 file changed