diff options
| author | Bhasker Hariharan <bhaskerh@google.com> | 2020-03-16 08:02:05 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-03-16 08:03:27 -0700 |
| commit | 52758e16e0d1e67b3cdd56e04abfce663607ac42 (patch) | |
| tree | 0a801c9546e5bfc7739d6e55abc40f6b76335630 | |
| parent | 97127750289b49dd5e29f8ddb4209137e47fe52d (diff) | |
Prevent vnetHdr from escaping in WritePacket.
PiperOrigin-RevId: 301157950
| -rw-r--r-- | pkg/tcpip/link/fdbased/endpoint.go | 2 | ||||
| -rw-r--r-- | pkg/tcpip/link/fdbased/endpoint_unsafe.go | 9 |
2 files changed, 6 insertions, 5 deletions
diff --git a/pkg/tcpip/link/fdbased/endpoint.go b/pkg/tcpip/link/fdbased/endpoint.go index a753fb243..3b36b9673 100644 --- a/pkg/tcpip/link/fdbased/endpoint.go +++ b/pkg/tcpip/link/fdbased/endpoint.go @@ -407,7 +407,6 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, protocol tcpip.Ne if e.Capabilities()&stack.CapabilityHardwareGSO != 0 { vnetHdr := virtioNetHdr{} - vnetHdrBuf := vnetHdrToByteSlice(&vnetHdr) if gso != nil { vnetHdr.hdrLen = uint16(pkt.Header.UsedLength()) if gso.NeedsCsum { @@ -428,6 +427,7 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, protocol tcpip.Ne } } + vnetHdrBuf := vnetHdrToByteSlice(&vnetHdr) return rawfile.NonBlockingWrite3(e.fds[0], vnetHdrBuf, pkt.Header.View(), pkt.Data.ToView()) } diff --git a/pkg/tcpip/link/fdbased/endpoint_unsafe.go b/pkg/tcpip/link/fdbased/endpoint_unsafe.go index 97a477b61..d81858353 100644 --- a/pkg/tcpip/link/fdbased/endpoint_unsafe.go +++ b/pkg/tcpip/link/fdbased/endpoint_unsafe.go @@ -24,9 +24,10 @@ import ( const virtioNetHdrSize = int(unsafe.Sizeof(virtioNetHdr{})) func vnetHdrToByteSlice(hdr *virtioNetHdr) (slice []byte) { - sh := (*reflect.SliceHeader)(unsafe.Pointer(&slice)) - sh.Data = uintptr(unsafe.Pointer(hdr)) - sh.Len = virtioNetHdrSize - sh.Cap = virtioNetHdrSize + *(*reflect.SliceHeader)(unsafe.Pointer(&slice)) = reflect.SliceHeader{ + Data: uintptr((unsafe.Pointer(hdr))), + Len: virtioNetHdrSize, + Cap: virtioNetHdrSize, + } return } |