i3c: fix refcount inconsistency in i3c_master_register

In `i3c_master_register`, a possible refcount inconsistency has been
identified, causing possible resource leak.

Function `of_node_get` increases the refcount of `parent->of_node`. If
function `i3c_bus_init` fails, the function returns immediately without
a corresponding decrease, resulting in an inconsistent refcounter.

Move call i3c_bus_init() after device_initialize() to let callback
i3c_masterdev_release() release of_node.

Reported-by: Shuhao Fu <sfual@cse.ust.hk>
Closes: https://lore.kernel.org/linux-i3c/aO2tjp_FsV_WohPG@osx.local/T/#m2c05a982beeb14e7bf039c1d8db856734bf234c7
Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20251016143814.2551256-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index d946db75df706812254e4e40b7f3c4482d2f8e77..66513a27e6e776d251203b286bcaecb9d8fc67b9 100644 (file)
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2883,10 +2883,6 @@ int i3c_master_register(struct i3c_master_controller *master,
        INIT_LIST_HEAD(&master->boardinfo.i2c);
        INIT_LIST_HEAD(&master->boardinfo.i3c);
 
-       ret = i3c_bus_init(i3cbus, master->dev.of_node);
-       if (ret)
-               return ret;
-
        device_initialize(&master->dev);
        dev_set_name(&master->dev, "i3c-%d", i3cbus->id);
 
@@ -2894,6 +2890,10 @@ int i3c_master_register(struct i3c_master_controller *master,
        master->dev.coherent_dma_mask = parent->coherent_dma_mask;
        master->dev.dma_parms = parent->dma_parms;
 
+       ret = i3c_bus_init(i3cbus, master->dev.of_node);
+       if (ret)
+               goto err_put_dev;
+
        ret = of_populate_i3c_bus(master);
        if (ret)
                goto err_put_dev;