[PATCH] media: cx231xx: fix devres lifetime

[PATCH] media: cx231xx: fix devres lifetime

[Johan Hovold]

USB drivers bind to USB interfaces and any device managed resources
should have their lifetime tied to the interface rather than parent USB
device. This avoids issues like memory leaks when drivers are unbound
without their devices being physically disconnected (e.g. on probe
deferral or configuration changes).

Fix the driver state lifetime so that it is released on driver unbind.

Fixes: 184a82784d50 ("[media] cx231xx: use devm_ functions to allocate memory")
Cc: stable@vger.kernel.org	# 3.17
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/media/usb/cx231xx/cx231xx-cards.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
index b75535d6abaf..69b24205bc56 100644
--- a/drivers/media/usb/cx231xx/cx231xx-cards.c
+++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
@@ -1573,7 +1573,8 @@ static int cx231xx_init_v4l2(struct cx231xx *dev,
 		 dev->video_mode.end_point_addr,
 		 dev->video_mode.num_alt);
 
-	dev->video_mode.alt_max_pkt_size = devm_kmalloc_array(&udev->dev, 32, dev->video_mode.num_alt, GFP_KERNEL);
+	dev->video_mode.alt_max_pkt_size = devm_kmalloc_array(&interface->dev, 32,
+							      dev->video_mode.num_alt, GFP_KERNEL);
 	if (dev->video_mode.alt_max_pkt_size == NULL)
 		return -ENOMEM;
 
@@ -1614,7 +1615,8 @@ static int cx231xx_init_v4l2(struct cx231xx *dev,
 		 dev->vbi_mode.num_alt);
 
 	/* compute alternate max packet sizes for vbi */
-	dev->vbi_mode.alt_max_pkt_size = devm_kmalloc_array(&udev->dev, 32, dev->vbi_mode.num_alt, GFP_KERNEL);
+	dev->vbi_mode.alt_max_pkt_size = devm_kmalloc_array(&interface->dev, 32,
+							    dev->vbi_mode.num_alt, GFP_KERNEL);
 	if (dev->vbi_mode.alt_max_pkt_size == NULL)
 		return -ENOMEM;
 
@@ -1656,7 +1658,9 @@ static int cx231xx_init_v4l2(struct cx231xx *dev,
 		 "sliced CC EndPoint Addr 0x%x, Alternate settings: %i\n",
 		 dev->sliced_cc_mode.end_point_addr,
 		 dev->sliced_cc_mode.num_alt);
-	dev->sliced_cc_mode.alt_max_pkt_size = devm_kmalloc_array(&udev->dev, 32, dev->sliced_cc_mode.num_alt, GFP_KERNEL);
+	dev->sliced_cc_mode.alt_max_pkt_size = devm_kmalloc_array(&interface->dev, 32,
+								  dev->sliced_cc_mode.num_alt,
+								  GFP_KERNEL);
 	if (dev->sliced_cc_mode.alt_max_pkt_size == NULL)
 		return -ENOMEM;
 
@@ -1720,7 +1724,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
 	udev = interface_to_usbdev(interface);
 
 	/* allocate memory for our device state and initialize it */
-	dev = devm_kzalloc(&udev->dev, sizeof(*dev), GFP_KERNEL);
+	dev = devm_kzalloc(&interface->dev, sizeof(*dev), GFP_KERNEL);
 	if (dev == NULL) {
 		retval = -ENOMEM;
 		goto err_if;
@@ -1850,7 +1854,9 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
 			 dev->ts1_mode.end_point_addr,
 			 dev->ts1_mode.num_alt);
 
-		dev->ts1_mode.alt_max_pkt_size = devm_kmalloc_array(&udev->dev, 32, dev->ts1_mode.num_alt, GFP_KERNEL);
+		dev->ts1_mode.alt_max_pkt_size = devm_kmalloc_array(&interface->dev, 32,
+								    dev->ts1_mode.num_alt,
+								    GFP_KERNEL);
 		if (dev->ts1_mode.alt_max_pkt_size == NULL) {
 			retval = -ENOMEM;
 			goto err_video_alt;
-- 
2.52.0

Re: [PATCH] media: cx231xx: fix devres lifetime

[Greg KH]

On Fri, Mar 27, 2026 at 11:43:55AM +0100, Johan Hovold wrote:
> USB drivers bind to USB interfaces and any device managed resources
> should have their lifetime tied to the interface rather than parent USB
> device. This avoids issues like memory leaks when drivers are unbound
> without their devices being physically disconnected (e.g. on probe
> deferral or configuration changes).
> 
> Fix the driver state lifetime so that it is released on driver unbind.

Wow, I bet we have a lot of these now, did you find this with a script
or something that you can run over the whole tree?

thanks,

greg k-h

Re: [PATCH] media: cx231xx: fix devres lifetime

[Johan Hovold]

On Fri, Mar 27, 2026 at 12:08:24PM +0100, Greg Kroah-Hartman wrote:
> On Fri, Mar 27, 2026 at 11:43:55AM +0100, Johan Hovold wrote:
> > USB drivers bind to USB interfaces and any device managed resources
> > should have their lifetime tied to the interface rather than parent USB
> > device. This avoids issues like memory leaks when drivers are unbound
> > without their devices being physically disconnected (e.g. on probe
> > deferral or configuration changes).
> > 
> > Fix the driver state lifetime so that it is released on driver unbind.
> 
> Wow, I bet we have a lot of these now, did you find this with a script
> or something that you can run over the whole tree?

I spotted one driver that got this wrong while fixing another bug and
grepped for similar issues tree wide.

I think I got most of them fixed now, but I'll do another pass in case
my grep patterns were too restrictive (e.g. I think they were limited to
probe functions).

Johan