diff options
| author | Rainer Weikusat <rweikusat@mobileactivedefense.com> | 2016-02-08 18:47:19 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-03 15:07:06 -0800 |
| commit | 2f46f069ccfb28e6fdaa6798544fd30b72835b04 (patch) | |
| tree | 73bbe7fde065df51cf696d41a2458be0260b6eb1 /net/unix/af_unix.c | |
| parent | 6b567a1abd72a4deb95126f164afcf62a3e091a1 (diff) | |
af_unix: Don't set err in unix_stream_read_generic unless there was an error
[ Upstream commit 1b92ee3d03af6643df395300ba7748f19ecdb0c5 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/unix/af_unix.c')
| -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 6de41c33a9db..265412c95d94 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2270,13 +2270,15 @@ 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); @@ -2322,9 +2324,11 @@ 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, |