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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Luiz Augusto von Dentz <luiz.von.dentz@intel.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0085/1039] Bluetooth: L2CAP: Fix not initializing sk_peer_pid
Date:   Mon, 24 Jan 2022 19:31:14 +0100
Message-Id: <20220124184128.011755111@linuxfoundation.org>
In-Reply-To: <20220124184125.121143506@linuxfoundation.org>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

[ Upstream commit f5ff291098f70a70b344df1e388596755c3c8315 ]

In order to group sockets being connected using L2CAP_MODE_EXT_FLOWCTL
the pid is used but sk_peer_pid was not being initialized as it is
currently only done for af_unix.

Fixes: b48596d1dc25 ("Bluetooth: L2CAP: Add get_peer_pid callback")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bluetooth/l2cap_sock.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 160c016a5dfb9..4574c5cb1b596 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -172,6 +172,21 @@ done:
 	return err;
 }
 
+static void l2cap_sock_init_pid(struct sock *sk)
+{
+	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
+
+	/* Only L2CAP_MODE_EXT_FLOWCTL ever need to access the PID in order to
+	 * group the channels being requested.
+	 */
+	if (chan->mode != L2CAP_MODE_EXT_FLOWCTL)
+		return;
+
+	spin_lock(&sk->sk_peer_lock);
+	sk->sk_peer_pid = get_pid(task_tgid(current));
+	spin_unlock(&sk->sk_peer_lock);
+}
+
 static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
 			      int alen, int flags)
 {
@@ -243,6 +258,8 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
 	if (chan->psm && bdaddr_type_is_le(chan->src_type) && !chan->mode)
 		chan->mode = L2CAP_MODE_LE_FLOWCTL;
 
+	l2cap_sock_init_pid(sk);
+
 	err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid),
 				 &la.l2_bdaddr, la.l2_bdaddr_type);
 	if (err)
@@ -298,6 +315,8 @@ static int l2cap_sock_listen(struct socket *sock, int backlog)
 		goto done;
 	}
 
+	l2cap_sock_init_pid(sk);
+
 	sk->sk_max_ack_backlog = backlog;
 	sk->sk_ack_backlog = 0;
 
-- 
2.34.1