1 files changed, 14 insertions, 5 deletions

diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go
index 150297ab9..f5b6ca0b9 100644
--- a/pkg/tcpip/stack/route.go
+++ b/pkg/tcpip/stack/route.go
@@ -153,17 +153,20 @@ func (r *Route) IsResolutionRequired() bool {
 }
 
 // WritePacket writes the packet through the given route.
-func (r *Route) WritePacket(gso *GSO, params NetworkHeaderParams, pkt PacketBuffer) *tcpip.Error {
+func (r *Route) WritePacket(gso *GSO, params NetworkHeaderParams, pkt *PacketBuffer) *tcpip.Error {
 	if !r.ref.isValidForOutgoing() {
 		return tcpip.ErrInvalidEndpointState
 	}
 
+	// WritePacket takes ownership of pkt, calculate numBytes first.
+	numBytes := pkt.Header.UsedLength() + pkt.Data.Size()
+
 	err := r.ref.ep.WritePacket(r, gso, params, pkt)
 	if err != nil {
 		r.Stats().IP.OutgoingPacketErrors.Increment()
 	} else {
 		r.ref.nic.stats.Tx.Packets.Increment()
-		r.ref.nic.stats.Tx.Bytes.IncrementBy(uint64(pkt.Header.UsedLength() + pkt.Data.Size()))
+		r.ref.nic.stats.Tx.Bytes.IncrementBy(uint64(numBytes))
 	}
 	return err
 }
@@ -175,9 +178,12 @@ func (r *Route) WritePackets(gso *GSO, pkts PacketBufferList, params NetworkHead
 		return 0, tcpip.ErrInvalidEndpointState
 	}
 
+	// WritePackets takes ownership of pkt, calculate length first.
+	numPkts := pkts.Len()
+
 	n, err := r.ref.ep.WritePackets(r, gso, pkts, params)
 	if err != nil {
-		r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(pkts.Len() - n))
+		r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(numPkts - n))
 	}
 	r.ref.nic.stats.Tx.Packets.IncrementBy(uint64(n))
 
@@ -193,17 +199,20 @@ func (r *Route) WritePackets(gso *GSO, pkts PacketBufferList, params NetworkHead
 
 // WriteHeaderIncludedPacket writes a packet already containing a network
 // header through the given route.
-func (r *Route) WriteHeaderIncludedPacket(pkt PacketBuffer) *tcpip.Error {
+func (r *Route) WriteHeaderIncludedPacket(pkt *PacketBuffer) *tcpip.Error {
 	if !r.ref.isValidForOutgoing() {
 		return tcpip.ErrInvalidEndpointState
 	}
 
+	// WriteHeaderIncludedPacket takes ownership of pkt, calculate numBytes first.
+	numBytes := pkt.Data.Size()
+
 	if err := r.ref.ep.WriteHeaderIncludedPacket(r, pkt); err != nil {
 		r.Stats().IP.OutgoingPacketErrors.Increment()
 		return err
 	}
 	r.ref.nic.stats.Tx.Packets.Increment()
-	r.ref.nic.stats.Tx.Bytes.IncrementBy(uint64(pkt.Data.Size()))
+	r.ref.nic.stats.Tx.Bytes.IncrementBy(uint64(numBytes))
 	return nil
 }