Fix potential invalid memory access

[project/odhcpd.git] / src / dhcpv6-ia.c

diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index de44581..1476e02 100644 (file)
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -596,7 +596,10 @@ static void update(struct interface *iface)
        }
 
        struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
-       border->assigned = 1 << (64 - minprefix);
+       if (minprefix <= 32 || minprefix > 64)
+               border->assigned = 1U << (64 - minprefix);
+       else
+               border->assigned = 0;
 
        bool change = len != (int)iface->ia_addr_len;
        for (int i = 0; !change && i < len; ++i)