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Subject[PATCH 1/2] net/x25: Fix x25_neigh refcnt leak when x25_connect() fails
Date
x25_connect() invokes x25_get_neigh(), which returns a reference of the
specified x25_neigh object to "x25->neighbour" with increased refcnt.

When x25_connect() returns, local variable "x25" and "x25->neighbour"
become invalid, so the refcount should be decreased to keep refcount
balanced.

The reference counting issue happens in one exception handling path of
x25_connect(). When sock state is not TCP_ESTABLISHED and its flags
include O_NONBLOCK, the function forgets to decrease the refcnt
increased by x25_get_neigh(), causing a refcnt leak.

Fix this issue by jumping to "out_put_neigh" label when x25_connect()
fails.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
net/x25/af_x25.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index d5b09bbff375..e6571c56209b 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -816,7 +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;
+ goto out_put_neigh;

rc = x25_wait_for_connection_establishment(sk);
if (rc)
--
2.7.4
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