On 02/05/2016 05:30 PM, Rainer Weikusat wrote: > The present unix_stream_read_generic contains various code sequences of > the form > > err = -EDISASTER; > if (<test>) > goto out; > > This has the unfortunate side effect of possibly causing the error code > to bleed through to the final > > out: > return copied ? : err; > > and then to be wrongly returned if no data was copied because the caller > didn't supply a data buffer, as demonstrated by the program available at > > http://pad.lv/1540731 > > Change it such that err is only set if an error condition was detected. > > Signed-off-by: Rainer Weikusat <rweiku...@mobileactivedefense.com> > --- > > With proper subject this time (at least I hope so). > > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > index 49d5093..138787d 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -2277,13 +2277,15 @@ static int unix_stream_read_generic(struct > unix_stream_read_state *state) > size_t size = state->size; > unsigned int last_len; > > - err = -EINVAL; > - if (sk->sk_state != TCP_ESTABLISHED) > + if (sk->sk_state != TCP_ESTABLISHED) { > + err = -EINVAL; > goto out; > + } > > - err = -EOPNOTSUPP; > - if (flags & MSG_OOB) > + if (flags & MSG_OOB) { > + err = -EOPNOTSUPP; > goto out; > + } > > target = sock_rcvlowat(sk, flags & MSG_WAITALL, size); > timeo = sock_rcvtimeo(sk, noblock); > @@ -2329,9 +2331,11 @@ again: > goto unlock; > > unix_state_unlock(sk); > - err = -EAGAIN; > - if (!timeo) > + if (!timeo) { > + err = -EAGAIN; > break; > + } > + > mutex_unlock(&u->readlock); > > timeo = unix_stream_data_wait(sk, timeo, last, I tested your patch, Rainer. I can confirm that it fixes the reported bug[0].
Thanks for the quick response! Joe [0] http://pad.lv/1540731
