diff options
| author | Amanda Tait <atait@google.com> | 2019-02-25 10:01:25 -0800 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2019-02-25 10:02:29 -0800 |
| commit | c14a1a161869804af5ae2f1f73fd8eeb135ff043 (patch) | |
| tree | 1a579653fea54fce3943c5dc4567563a646c05ef | |
| parent | 317c0324c9c73e1c6d6c9cfa7e9cdbfbf1f63b06 (diff) | |
Fix race condition in NIC.DeliverNetworkPacket
cl/234850781 introduced a race condition in NIC.DeliverNetworkPacket
by failing to hold a lock. This change fixes this regressesion by acquiring
a read lock before iterating through n.endpoints, and then releasing the lock
once iteration is complete.
PiperOrigin-RevId: 235549770
Change-Id: Ib0133288be512d478cf759c3314dc95ec3205d4b
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 43d7c2ec4..a6b04faaf 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -403,14 +403,19 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, _ tcpip.LinkAddr // route to each IPv4 network endpoint and let each endpoint handle the // packet. if dst == header.IPv4Broadcast { + // n.endpoints is mutex protected so acquire lock. + n.mu.RLock() for _, ref := range n.endpoints { + n.mu.RUnlock() if ref.protocol == header.IPv4ProtocolNumber && ref.tryIncRef() { r := makeRoute(protocol, dst, src, linkEP.LinkAddress(), ref) r.RemoteLinkAddress = remote ref.ep.HandlePacket(&r, vv) ref.decRef() } + n.mu.RLock() } + n.mu.RUnlock() return } |