Re: [syzbot] [media?] [usb?] memory leak in v4l2_ctrl_handler_init_class (2)

[shaurya <ssranevjti@gmail.com>]

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#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

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From 0b4eb46c6f9f4dbf9dc9d9b07a5bc8b5ece04b8d Mon Sep 17 00:00:00 2001
From: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
Date: Wed, 26 Nov 2025 01:47:41 +0530
Subject: [PATCH] media: radio-keene: fix memory leak in error path

Fix a memory leak in usb_keene_probe() when v4l2_device_register()
fails. The v4l2 control handler was initialized and controls were
added, but if v4l2_device_register() failed, the handler was never
freed, leaking the allocated memory for the handler buckets and
control structures.

Consolidate the error handling by adding an err_hdl label that
ensures v4l2_ctrl_handler_free() is called for all error paths
after the handler is initialized.

Reported-by: syzbot+a41b73dce23962a74c72@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a41b73dce23962a74c72
Fixes: fc39f46b8e82 ("[media] radio-keene: add a driver for the Keene FM Transmitter")
Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
---
 drivers/media/radio/radio-keene.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/radio/radio-keene.c b/drivers/media/radio/radio-keene.c
index f3b57f0cb1ec..84916b5ebcb2 100644
--- a/drivers/media/radio/radio-keene.c
+++ b/drivers/media/radio/radio-keene.c
@@ -337,14 +337,12 @@ static int usb_keene_probe(struct usb_interface *intf,
 	radio->stereo = true;
 	if (hdl->error) {
 		retval = hdl->error;
-
-		v4l2_ctrl_handler_free(hdl);
-		goto err_v4l2;
+		goto err_hdl;
 	}
 	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
 	if (retval < 0) {
 		dev_err(&intf->dev, "couldn't register v4l2_device\n");
-		goto err_v4l2;
+		goto err_hdl;
 	}
 
 	mutex_init(&radio->lock);
@@ -383,6 +381,8 @@ static int usb_keene_probe(struct usb_interface *intf,
 
 err_vdev:
 	v4l2_device_unregister(&radio->v4l2_dev);
+err_hdl:
+	v4l2_ctrl_handler_free(&radio->hdl);
 err_v4l2:
 	kfree(radio->buffer);
 	kfree(radio);
-- 
2.34.1