Fix NULL pointer dereference in lldpd_dot3_power_pd_pse

selected_port might be NULL after the loop if, for example,
no PSE was found among the neighbours.

This fixes a crash that occured with a device connected to
a non-PoE, LLDP-enabled switch via a PoE midspan.

diff --git a/src/daemon/lldpd.c b/src/daemon/lldpd.c
index 51d690fe4371bdd0fa5cbfa489c39719da9fadbf..7b5c1267de3e279b7cb3e19461a0422e9275a8d7 100644 (file)
--- a/src/daemon/lldpd.c
+++ b/src/daemon/lldpd.c
@@ -974,7 +974,7 @@ lldpd_dot3_power_pd_pse(struct lldpd_hardware *hardware)
                if (!selected_port || port->p_lastupdate > selected_port->p_lastupdate)
                        selected_port = port;
        }
-       if (selected_port->p_power.allocated != hardware->h_lport.p_power.allocated) {
+       if (selected_port && selected_port->p_power.allocated != hardware->h_lport.p_power.allocated) {
                log_info("receive", "for %s, PSE told us allocated is now %d instead of %d",
                    hardware->h_ifname,
                    selected_port->p_power.allocated,