ldb: do not allow adding a DN as a base to itself

If you try to add a dn to itself, it expands as it goes. The resulting
loop cannot end well.

It looks like this in Python:

    dn = ldb.Dn(ldb.Ldb(), 'CN=y,DC=x')
    dn.add_base(dn)

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>

diff --git a/lib/ldb/common/ldb_dn.c b/lib/ldb/common/ldb_dn.c
index 2e98f3914673bf2b605f50f19bdcd0196efd2812..eccb4a0ce4b510501253108541f03967fd37c68a 100644 (file)
--- a/lib/ldb/common/ldb_dn.c
+++ b/lib/ldb/common/ldb_dn.c
@@ -1357,6 +1357,10 @@ bool ldb_dn_add_base(struct ldb_dn *dn, struct ldb_dn *base)
                return false;
        }
 
+       if (dn == base) {
+               return false; /* or we will visit infinity */
+       }
+
        if (dn->components) {
                unsigned int i;