[PATCH 5.10.y 2/2] usb: gadget: f_hid: fix device reference leak in hidg_alloc()

[Sasha Levin <sashal@kernel.org>]

From: Guangshuo Li <lgs201920130244@gmail.com>

[ Upstream commit 4f88d65def6f3c90121601b4f62a4c967f3063a6 ]

hidg_alloc() initializes hidg->dev with device_initialize() before
calling dev_set_name(). If dev_set_name() fails, the function currently
jumps to err_unlock and returns without calling put_device().

This leaves the device reference unbalanced and prevents hidg_release()
from being called. Calling put_device() here is also safe, since
hidg_release() only frees resources owned by hidg.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Route the dev_set_name() failure path through err_put_device so the
device reference is dropped properly.

Fixes: 89ff3dfac604 ("usb: gadget: f_hid: fix f_hidg lifetime vs cdev")
Cc: stable <stable@kernel.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Johan Hovold johan@kernel.org
Link: https://patch.msgid.link/20260413142119.2977716-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/function/f_hid.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 7c5916caf61b30..d5ff9f06c68622 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -1278,7 +1278,7 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 	hidg->dev.devt = MKDEV(major, opts->minor);
 	ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
 	if (ret)
-		goto err_unlock;
+		goto err_put_device;
 
 	hidg->bInterfaceSubClass = opts->subclass;
 	hidg->bInterfaceProtocol = opts->protocol;
@@ -1313,7 +1313,6 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 
 err_put_device:
 	put_device(&hidg->dev);
-err_unlock:
 	mutex_unlock(&opts->lock);
 	return ERR_PTR(ret);
 }
-- 
2.53.0