net/atm: sk_err_soft must be positive
The sk_err and sk_err_soft fields are positive errno values and
userspace applications rely on this when using getsockopt(SO_ERROR).
ATM code places an -errno into sk_err_soft in sigd_send() and returns it
from svc_addparty()/svc_dropparty().
Although I am not familiar with ATM code I came to this conclusion
because:
1. sigd_send() msg->type cases as_okay and as_error both have:
sk->sk_err = -msg->reply;
while the as_addparty and as_dropparty cases have:
sk->sk_err_soft = msg->reply;
This is the source of the inconsistency.
2. svc_addparty() returns an -errno and assumes sk_err_soft is also an
-errno:
if (flags & O_NONBLOCK) {
error = -EINPROGRESS;
goto out;
}
...
error = xchg(&sk->sk_err_soft, 0);
out:
release_sock(sk);
return error;
This shows that sk_err_soft is indeed being treated as an -errno.
This patch ensures that sk_err_soft is always a positive errno.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/atm/svc.c b/net/atm/svc.c
index 3fa0a9e..878563a 100644
--- a/net/atm/svc.c
+++ b/net/atm/svc.c
@@ -546,7 +546,7 @@
schedule();
}
finish_wait(sk_sleep(sk), &wait);
- error = xchg(&sk->sk_err_soft, 0);
+ error = -xchg(&sk->sk_err_soft, 0);
out:
release_sock(sk);
return error;
@@ -573,7 +573,7 @@
error = -EUNATCH;
goto out;
}
- error = xchg(&sk->sk_err_soft, 0);
+ error = -xchg(&sk->sk_err_soft, 0);
out:
release_sock(sk);
return error;