From: Sergey Matveev <stargrave@stargrave.org>
Date: Mon, 3 Apr 2017 20:34:42 +0000 (+0300)
Subject: Skip possible invalid memory address during the race
X-Git-Tag: 7.3^2~2
X-Git-Url: http://www.git.cypherpunks.ru/?p=govpn.git;a=commitdiff_plain;h=8cdc4548bc7b6c8b774c2be3b7cd350756df25b6

Skip possible invalid memory address during the race
---

diff --git a/src/cypherpunks.ru/govpn/cmd/govpn-server/tcp.go b/src/cypherpunks.ru/govpn/cmd/govpn-server/tcp.go
index c36da3f..61eb1e0 100644
--- a/src/cypherpunks.ru/govpn/cmd/govpn-server/tcp.go
+++ b/src/cypherpunks.ru/govpn/cmd/govpn-server/tcp.go
@@ -99,10 +99,18 @@ func handleTCP(conn net.Conn) {
 		peersByIDLock.RLock()
 		addrPrev, exists := peersByID[*peer.ID]
 		peersByIDLock.RUnlock()
+		var peerPrev *PeerState
 		if exists {
 			peersLock.Lock()
-			peers[addrPrev].terminator <- struct{}{}
-			tap = peers[addrPrev].tap
+			peerPrev = peers[addrPrev]
+			if peerPrev == nil {
+				exists = false
+				peersLock.Unlock()
+			}
+		}
+		if exists {
+			peerPrev.terminator <- struct{}{}
+			tap = peerPrev.tap
 			ps = &PeerState{
 				peer:       peer,
 				tap:        tap,
diff --git a/src/cypherpunks.ru/govpn/cmd/govpn-server/udp.go b/src/cypherpunks.ru/govpn/cmd/govpn-server/udp.go
index dbfc689..0373517 100644
--- a/src/cypherpunks.ru/govpn/cmd/govpn-server/udp.go
+++ b/src/cypherpunks.ru/govpn/cmd/govpn-server/udp.go
@@ -136,12 +136,20 @@ func startUDP() {
 			peersByIDLock.RLock()
 			addrPrev, exists = peersByID[*peer.ID]
 			peersByIDLock.RUnlock()
+			var peerPrev *PeerState
 			if exists {
 				peersLock.Lock()
-				peers[addrPrev].terminator <- struct{}{}
+				peerPrev = peers[addrPrev]
+				if peerPrev == nil {
+					exists = false
+					peersLock.Unlock()
+				}
+			}
+			if exists {
+				peerPrev.terminator <- struct{}{}
 				psNew := &PeerState{
 					peer:       peer,
-					tap:        peers[addrPrev].tap,
+					tap:        peerPrev.tap,
 					terminator: make(chan struct{}),
 				}
 				go func(peer *govpn.Peer, tap *govpn.TAP, terminator chan struct{}) {