[PATCH] Fixed integer overflow in e1000e

[andrew@daynix.com]

From: Andrew Melnychenko <andrew@daynix.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1737400
Fixed setting max_queue_num if there are no peers in NICConf. qemu_new_nic() creates NICState with 1 NetClientState(index 0) without peers, set max_queue_num to 0 - It prevents undefined behavior and possible crashes, especially during pcie hotplug.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
---
 hw/net/e1000e.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/net/e1000e.c b/hw/net/e1000e.c
index a91dbdca3c..f2cc1552c5 100644
--- a/hw/net/e1000e.c
+++ b/hw/net/e1000e.c
@@ -328,7 +328,7 @@ e1000e_init_net_peer(E1000EState *s, PCIDevice *pci_dev, uint8_t *macaddr)
     s->nic = qemu_new_nic(&net_e1000e_info, &s->conf,
         object_get_typename(OBJECT(s)), dev->id, s);
 
-    s->core.max_queue_num = s->conf.peers.queues - 1;
+    s->core.max_queue_num = s->conf.peers.queues ? s->conf.peers.queues - 1 : 0;
 
     trace_e1000e_mac_set_permanent(MAC_ARG(macaddr));
     memcpy(s->core.permanent_mac, macaddr, sizeof(s->core.permanent_mac));
-- 
2.24.1