qdisc: validate frames going through the direct_xmit path
In commit 50cbe9ab5f8d ("net: Validate xmit SKBs right when we
pull them out of the qdisc") the validation code was moved out of
dev_hard_start_xmit and into dequeue_skb.
However this overlooked the fact that we do not always enqueue
the skb onto a qdisc. First situation is if qdisc have flag
TCQ_F_CAN_BYPASS and qdisc is empty. Second situation is if
there is no qdisc on the device, which is a common case for
software devices.
Originally spotted and inital patch by Alexander Duyck.
As a result Alex was seeing issues trying to connect to a
vhost_net interface after commit 50cbe9ab5f8d was applied.
Added a call to validate_xmit_skb() in __dev_xmit_skb(), in the
code path for qdiscs with TCQ_F_CAN_BYPASS flag, and in
__dev_queue_xmit() when no qdisc.
Also handle the error situation where dev_hard_start_xmit() could
return a skb list, and does not return dev_xmit_complete(rc) and
falls through to the kfree_skb(), in that situation it should
call kfree_skb_list().
Fixes: 50cbe9ab5f8d ("net: Validate xmit SKBs right when we pull them out of the qdisc")
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 3774afc..2f3dbd6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2739,7 +2739,8 @@
qdisc_bstats_update(q, skb);
- if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
+ skb = validate_xmit_skb(skb, dev);
+ if (skb && sch_direct_xmit(skb, q, dev, txq, root_lock)) {
if (unlikely(contended)) {
spin_unlock(&q->busylock);
contended = false;
@@ -2879,6 +2880,10 @@
if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
goto recursion_alert;
+ skb = validate_xmit_skb(skb, dev);
+ if (!skb)
+ goto drop;
+
HARD_TX_LOCK(dev, txq, cpu);
if (!netif_xmit_stopped(txq)) {
@@ -2904,10 +2909,11 @@
}
rc = -ENETDOWN;
+drop:
rcu_read_unlock_bh();
atomic_long_inc(&dev->tx_dropped);
- kfree_skb(skb);
+ kfree_skb_list(skb);
return rc;
out:
rcu_read_unlock_bh();