From: Dean Jenkins <Dean_Jenkins@xxxxxxxxxx> During execution of l2cap_sock_shutdown() which might sleep, the sk and chan structures can be in an unlocked condition which potentially allows the structures to be freed by other running threads. Therefore, there is a possibility of a malfunction or memory reuse after being freed. Keep the sk and chan structures alive during the execution of l2cap_sock_shutdown() by using their respective hold and put functions. This allows the structures to be freeable at the end of l2cap_sock_shutdown(). Signed-off-by: Kautuk Consul <Kautuk_Consul@xxxxxxxxxx> Signed-off-by: Dean Jenkins <Dean_Jenkins@xxxxxxxxxx> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> --- net/bluetooth/l2cap_sock.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 071d35c9f3b4..e56d34f027dd 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1092,7 +1092,12 @@ static int l2cap_sock_shutdown(struct socket *sock, int how) if (!sk) return 0; + /* prevent sk structure from being freed whilst unlocked */ + sock_hold(sk); + chan = l2cap_pi(sk)->chan; + /* prevent chan structure from being freed whilst unlocked */ + l2cap_chan_hold(chan); conn = chan->conn; if (conn) @@ -1126,6 +1131,9 @@ static int l2cap_sock_shutdown(struct socket *sock, int how) if (conn) mutex_unlock(&conn->chan_lock); + l2cap_chan_put(chan); + sock_put(sk); + return err; } -- 2.17.1
