[PATCH 6.4 118/800] net/handshake: Unpin sock->file if a handshake is cancelled

Greg Kroah-Hartman
2023-07-16T19:59:42Z

From: Chuck Lever <chuck.lever@oracle.com>

[ Upstream commit f921bd41001ccff2249f5f443f2917f7ef937daf ]

If user space never calls DONE, sock->file's reference count remains
elevated. Enable sock->file to be freed eventually in this case.

Reported-by: Jakub Kacinski <kuba@kernel.org>
Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/handshake/handshake.h | 1 +
net/handshake/request.c | 4 ++++
2 files changed, 5 insertions(+)

diff --git a/net/handshake/handshake.h b/net/handshake/handshake.h
index 4dac965c99df0..8aeaadca844fd 100644
--- a/net/handshake/handshake.h
+++ b/net/handshake/handshake.h
@@ -31,6 +31,7 @@ struct handshake_req {
struct list_head hr_list;
struct rhash_head hr_rhash;
unsigned long hr_flags;
+ struct file *hr_file;
const struct handshake_proto *hr_proto;
struct sock *hr_sk;
void (*hr_odestruct)(struct sock *sk);
diff --git a/net/handshake/request.c b/net/handshake/request.c
index 94d5cef3e048b..d78d41abb3d99 100644
--- a/net/handshake/request.c
+++ b/net/handshake/request.c
@@ -239,6 +239,7 @@ int handshake_req_submit(struct socket *sock, struct handshake_req *req,
}
req->hr_odestruct = req->hr_sk->sk_destruct;
req->hr_sk->sk_destruct = handshake_sk_destruct;
+ req->hr_file = sock->file;

ret = -EOPNOTSUPP;
net = sock_net(req->hr_sk);
@@ -334,6 +335,9 @@ bool handshake_req_cancel(struct sock *sk)
return false;
}

+ /* Request accepted and waiting for DONE */
+ fput(req->hr_file);
+
out_true:
trace_handshake_cancel(net, req, sk);

--
2.39.2