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From:   Eiichi Tsukata <eiichi.tsukata@nutanix.com>
To:     sgarzare@redhat.com, davem@davemloft.net, kuba@kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Eiichi Tsukata <eiichi.tsukata@nutanix.com>
Subject: [PATCH net v2] vsock: prevent unnecessary refcnt inc for nonblocking connect
Date:   Tue,  9 Nov 2021 00:15:02 +0000
Message-Id: <20211109001502.9152-1-eiichi.tsukata@nutanix.com>
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Currently vosck_connect() increments sock refcount for nonblocking
socket each time it's called, which can lead to memory leak if
it's called multiple times because connect timeout function decrements
sock refcount only once.

Fixes it by making vsock_connect() return -EALREADY immediately when
sock state is already SS_CONNECTING.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com>
---
 net/vmw_vsock/af_vsock.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index e2c0cfb334d2..fa8c1b623fa2 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1322,6 +1322,8 @@ static int vsock_connect(struct socket *sock, struct sockaddr *addr,
 		 * non-blocking call.
 		 */
 		err = -EALREADY;
+		if (flags & O_NONBLOCK)
+			goto out;
 		break;
 	default:
 		if ((sk->sk_state == TCP_LISTEN) ||
-- 
2.33.1