lib/nat: Fix clearAddresses/notify deadlock (ref #4601) (#4829)

clearAddresses write locks the struct and then calls notify. notify in turn tries to obtain a read lock on the same mutex. The result was a deadlock. This change unlocks the struct before calling notify.
This commit is contained in:
Graham Miln 2018-03-21 08:02:32 +01:00 committed by Jakob Borg
parent ac2e9b0e09
commit e7dc2f9190
2 changed files with 17 additions and 2 deletions

View File

@ -53,11 +53,11 @@ func (m *Mapping) clearAddresses() {
removed = append(removed, addr) removed = append(removed, addr)
delete(m.extAddresses, id) delete(m.extAddresses, id)
} }
m.expires = time.Time{}
m.mut.Unlock()
if len(removed) > 0 { if len(removed) > 0 {
m.notify(nil, removed) m.notify(nil, removed)
} }
m.expires = time.Time{}
m.mut.Unlock()
} }
func (m *Mapping) notify(added, removed []Address) { func (m *Mapping) notify(added, removed []Address) {

View File

@ -9,6 +9,8 @@ package nat
import ( import (
"net" "net"
"testing" "testing"
"github.com/syncthing/syncthing/lib/protocol"
) )
func TestMappingValidGateway(t *testing.T) { func TestMappingValidGateway(t *testing.T) {
@ -52,3 +54,16 @@ func TestMappingValidGateway(t *testing.T) {
} }
} }
} }
func TestMappingClearAddresses(t *testing.T) {
natSvc := NewService(protocol.EmptyDeviceID, nil)
// Mock a mapped port; avoids the need to actually map a port
ip := net.ParseIP("192.168.0.1")
m := natSvc.NewMapping(TCP, ip, 1024)
m.extAddresses["test"] = Address{
IP: ip,
Port: 1024,
}
// Now try and remove the mapped port; prior to #4829 this deadlocked
natSvc.RemoveMapping(m)
}