bcma: Fix memory leak for internally-handled cores

kmemleak reported that dev_name() of internally-handled cores were leaked
on driver unbinding. Let's use device_initialize() to take refcounts for
them and put_device() to properly free the related stuff.

While looking at it, there's another potential issue for those which should
be *registered* into driver core. If device_register() failed, we put
device once and freed bcma_device structures. In bcma_unregister_cores(),
they're treated as unregistered and we hit both UAF and double-free. That
smells not good and has also been fixed now.

Fixes: ab54bc8460b5 ("bcma: fill core details for every device")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210727025232.663-2-yuzenghui@huawei.com

diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
index 6535614..1df2b58 100644 (file)
--- a/drivers/bcma/main.c
+++ b/drivers/bcma/main.c
@@ -236,6 +236,7 @@ EXPORT_SYMBOL(bcma_core_irq);
 
 void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core)
 {
+       device_initialize(&core->dev);
        core->dev.release = bcma_release_core_dev;
        core->dev.bus = &bcma_bus_type;
        dev_set_name(&core->dev, "bcma%d:%d", bus->num, core->core_index);
@@ -277,11 +278,10 @@ static void bcma_register_core(struct bcma_bus *bus, struct bcma_device *core)
 {
        int err;
 
-       err = device_register(&core->dev);
+       err = device_add(&core->dev);
        if (err) {
                bcma_err(bus, "Could not register dev for core 0x%03X\n",
                         core->id.id);
-               put_device(&core->dev);
                return;
        }
        core->dev_registered = true;
@@ -372,7 +372,7 @@ void bcma_unregister_cores(struct bcma_bus *bus)
        /* Now noone uses internally-handled cores, we can free them */
        list_for_each_entry_safe(core, tmp, &bus->cores, list) {
                list_del(&core->list);
-               kfree(core);
+               put_device(&core->dev);
        }
 }