| Message ID | 20200109063114.23195-1-ms@dev.tdt.de |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | net/x25: fix nonblocking connect | expand |
From: Martin Schiller <ms@dev.tdt.de> Date: Thu, 9 Jan 2020 07:31:14 +0100 > This patch fixes 2 issues in x25_connect(): > > 1. It makes absolutely no sense to reset the neighbour and the > connection state after a (successful) nonblocking call of x25_connect. > This prevents any connection from being established, since the response > (call accept) cannot be processed. > > 2. Any further calls to x25_connect() while a call is pending should > simply return, instead of creating new Call Request (on different > logical channels). > > This patch should also fix the "KASAN: null-ptr-deref Write in > x25_connect" and "BUG: unable to handle kernel NULL pointer dereference > in x25_connect" bugs reported by syzbot. > > Signed-off-by: Martin Schiller <ms@dev.tdt.de> > Reported-by: syzbot+429c200ffc8772bfe070@syzkaller.appspotmail.com > Reported-by: syzbot+eec0c87f31a7c3b66f7b@syzkaller.appspotmail.com Applied and queued up for -stable, thanks.
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 2efe44a34644..d5b09bbff375 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -766,6 +766,10 @@ static int x25_connect(struct socket *sock, struct sockaddr *uaddr, if (sk->sk_state == TCP_ESTABLISHED) goto out; + rc = -EALREADY; /* Do nothing if call is already in progress */ + if (sk->sk_state == TCP_SYN_SENT) + goto out; + sk->sk_state = TCP_CLOSE; sock->state = SS_UNCONNECTED; @@ -812,7 +816,7 @@ static int x25_connect(struct socket *sock, struct sockaddr *uaddr, /* Now the loop */ rc = -EINPROGRESS; if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) - goto out_put_neigh; + goto out; rc = x25_wait_for_connection_establishment(sk); if (rc)
This patch fixes 2 issues in x25_connect(): 1. It makes absolutely no sense to reset the neighbour and the connection state after a (successful) nonblocking call of x25_connect. This prevents any connection from being established, since the response (call accept) cannot be processed. 2. Any further calls to x25_connect() while a call is pending should simply return, instead of creating new Call Request (on different logical channels). This patch should also fix the "KASAN: null-ptr-deref Write in x25_connect" and "BUG: unable to handle kernel NULL pointer dereference in x25_connect" bugs reported by syzbot. Signed-off-by: Martin Schiller <ms@dev.tdt.de> Reported-by: syzbot+429c200ffc8772bfe070@syzkaller.appspotmail.com Reported-by: syzbot+eec0c87f31a7c3b66f7b@syzkaller.appspotmail.com --- net/x25/af_x25.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)