[PATCH] net: fix null pointer dereference when parsing ICMP6_ROUTER_ADVERTISE messages

[Qiumiao Zhang]

During UEFI PXE boot in IPv6 network, if the DHCP server adopts stateful 
automatic
configuration, when the client receives the ICMP6_ROUTER_ADVERTISE message 
multicast
from the server, it will cause the problem of dereference null pointer and cause
the grub2 program to crash.

Fixes bug: https://savannah.gnu.org/bugs/index.php?62072
---
 grub-core/net/icmp6.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/grub-core/net/icmp6.c b/grub-core/net/icmp6.c
index 2cbd95d..264fc4a 100644
--- a/grub-core/net/icmp6.c
+++ b/grub-core/net/icmp6.c
@@ -477,7 +477,7 @@ grub_net_recv_icmp6_packet (struct grub_net_buff *nb,
 
            /* May not have gotten slaac info, find a global address on this
              card.  */
-           if (route_inf == NULL)
+           if (route_inf == NULL && orig_inf != NULL)
              {
                FOR_NET_NETWORK_LEVEL_INTERFACES (inf)
                {
-- 
2.19.1