most: core: fix resource leak in most_register_interface error paths

The function most_register_interface() did not correctly release resources
if it failed early (before registering the device). In these cases, it
returned an error code immediately, leaking the memory allocated for the
interface.

Fix this by initializing the device early via device_initialize() and
calling put_device() on all error paths.

The most_register_interface() is expected to call put_device() on
error which frees the resources allocated in the caller. The
put_device() either calls release_mdev() or dim2_release(),
depending on the caller.

Switch to using device_add() instead of device_register() to handle
the split initialization.

Acked-by: Abdun Nihaal <abdun.nihaal@gmail.com>
Signed-off-by: Navaneeth K <knavaneeth786@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/20251127165337.19172-1-knavaneeth786@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/most/core.c b/drivers/most/core.c
index da319d108ea1df91602cf70a0b4eca23777e3639..6277e6702ca8cd6343d716c362279e02897add71 100644 (file)
--- a/drivers/most/core.c
+++ b/drivers/most/core.c
@@ -1286,15 +1286,19 @@ int most_register_interface(struct most_interface *iface)
            !iface->poison_channel || (iface->num_channels > MAX_CHANNELS))
                return -EINVAL;
 
+       device_initialize(iface->dev);
+
        id = ida_alloc(&mdev_id, GFP_KERNEL);
        if (id < 0) {
                dev_err(iface->dev, "Failed to allocate device ID\n");
+               put_device(iface->dev);
                return id;
        }
 
        iface->p = kzalloc(sizeof(*iface->p), GFP_KERNEL);
        if (!iface->p) {
                ida_free(&mdev_id, id);
+               put_device(iface->dev);
                return -ENOMEM;
        }
 
@@ -1304,7 +1308,7 @@ int most_register_interface(struct most_interface *iface)
        iface->dev->bus = &mostbus;
        iface->dev->groups = interface_attr_groups;
        dev_set_drvdata(iface->dev, iface);
-       if (device_register(iface->dev)) {
+       if (device_add(iface->dev)) {
                dev_err(iface->dev, "Failed to register interface device\n");
                kfree(iface->p);
                put_device(iface->dev);