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>
1 file changed