diff options
| author | Brian Geffon <bgeffon@google.com> | 2018-06-08 10:32:30 -0700 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2018-06-08 10:33:25 -0700 |
| commit | 2f3895d6f7ad37915edcdd80706f880ce50c519c (patch) | |
| tree | 31a4be0b3fe7631e6f386b633d6e187adcba7fb9 | |
| parent | 5c51bc51e43a0f1d1f06ae490b0d352d1b483766 (diff) | |
rpcinet is not correctly handling MSG_TRUNC on recvmsg(2).
MSG_TRUNC can cause recvmsg(2) to return a value larger than
the buffer size. In this situation it's an indication that the
buffer was completely filled and that the msg was truncated.
Previously in rpcinet we were returning the buffer size but we
should actually be returning the payload length as returned by
the syscall.
PiperOrigin-RevId: 199814221
Change-Id: If09aa364219c1bf193603896fcc0dc5c55e85d21
| -rw-r--r-- | pkg/sentry/socket/rpcinet/socket.go | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/pkg/sentry/socket/rpcinet/socket.go b/pkg/sentry/socket/rpcinet/socket.go index 69cf604b7..c4ecb30f5 100644 --- a/pkg/sentry/socket/rpcinet/socket.go +++ b/pkg/sentry/socket/rpcinet/socket.go @@ -465,8 +465,8 @@ func (s *socketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags res, err := rpcRecvMsg(t, req) if err == nil { - n, e := dst.CopyOut(t, res.Data) - return int(n), res.Address.GetAddress(), res.Address.GetLength(), socket.ControlMessages{}, syserr.FromError(e) + _, e := dst.CopyOut(t, res.Data) + return int(res.Length), res.Address.GetAddress(), res.Address.GetLength(), socket.ControlMessages{}, syserr.FromError(e) } if err != syserr.ErrWouldBlock || flags&linux.MSG_DONTWAIT != 0 { return 0, nil, 0, socket.ControlMessages{}, err @@ -481,8 +481,8 @@ func (s *socketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags for { res, err := rpcRecvMsg(t, req) if err == nil { - n, e := dst.CopyOut(t, res.Data) - return int(n), res.Address.GetAddress(), res.Address.GetLength(), socket.ControlMessages{}, syserr.FromError(e) + _, e := dst.CopyOut(t, res.Data) + return int(res.Length), res.Address.GetAddress(), res.Address.GetLength(), socket.ControlMessages{}, syserr.FromError(e) } if err != syserr.ErrWouldBlock { return 0, nil, 0, socket.ControlMessages{}, err |