diff options
| author | Rainer Weikusat <rweikusat@mobileactivedefense.com> | 2016-02-08 18:47:19 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-02-16 12:48:04 -0500 |
| commit | 1b92ee3d03af6643df395300ba7748f19ecdb0c5 (patch) | |
| tree | 174da5394bc86b1f6a66a69ce9da19a688dae40a /net/unix | |
| parent | db92ea5d4df00271b57d79c2d03dae5a5d60fcc1 (diff) | |
| download | lwn-1b92ee3d03af6643df395300ba7748f19ecdb0c5.tar.gz lwn-1b92ee3d03af6643df395300ba7748f19ecdb0c5.zip | |
af_unix: Don't set err in unix_stream_read_generic unless there was an error
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.
Fixes: 3822b5c2fc62 ("af_unix: Revert 'lock_interruptible' in stream receive code")
Reported-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/unix')
| -rw-r--r-- | net/unix/af_unix.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 29be035f9c65..df923caa8389 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 (unlikely(sk->sk_state != TCP_ESTABLISHED)) { + err = -EINVAL; goto out; + } - err = -EOPNOTSUPP; - if (flags & MSG_OOB) + if (unlikely(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, |