thunderbolt: Fix memory leak in margining

BugLink: https://bugs.launchpad.net/bugs/2016877
commit acec726473822bc6b585961f4ca2a11fa7f28341 upstream.

Memory for the usb4->margining needs to be relased for the upstream port
of the router as well, even though the debugfs directory gets released
with the router device removal. Fix this.

Fixes: d0f1e0c2a699 ("thunderbolt: Add support for receiver lane margining")
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/thunderbolt/debugfs.c b/drivers/thunderbolt/debugfs.c
index 834bcad42e9fe8cfa5a1e065bed7b512f817bb0d..d89f92032c1c23eafd867a9912aab63c0c4d3009 100644 (file)
--- a/drivers/thunderbolt/debugfs.c
+++ b/drivers/thunderbolt/debugfs.c
@@ -942,7 +942,8 @@ static void margining_port_remove(struct tb_port *port)
 
        snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
        parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
-       debugfs_remove_recursive(debugfs_lookup("margining", parent));
+       if (parent)
+               debugfs_remove_recursive(debugfs_lookup("margining", parent));
 
        kfree(port->usb4->margining);
        port->usb4->margining = NULL;
@@ -967,19 +968,18 @@ static void margining_switch_init(struct tb_switch *sw)
 
 static void margining_switch_remove(struct tb_switch *sw)
 {
+       struct tb_port *upstream, *downstream;
        struct tb_switch *parent_sw;
-       struct tb_port *downstream;
        u64 route = tb_route(sw);
 
        if (!route)
                return;
 
-       /*
-        * Upstream is removed with the router itself but we need to
-        * remove the downstream port margining directory.
-        */
+       upstream = tb_upstream_port(sw);
        parent_sw = tb_switch_parent(sw);
        downstream = tb_port_at(route, parent_sw);
+
+       margining_port_remove(upstream);
        margining_port_remove(downstream);
 }