[PATCH] USB: cdc-acm: fix urb leak on disconnect

[PATCH] USB: cdc-acm: fix urb leak on disconnect

[Johan Hovold]

Make sure to drop the reference taken by usb_anchor_urb() when removing
URBs from the delayed URB anchor to prevent them from leaking when the
device is later disconnected.

Fixes: 140cb81ac8c6 ("USB: cdc-acm: fix broken runtime suspend")
Reported-by: Wentao Liang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/20260917161217.2161883-1-vulab@iscas.ac.cn/
Cc: stable@vger.kernel.org	# 3.16
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/class/cdc-acm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 7bc5329fa3ed..140e4f241b7a 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -783,6 +783,7 @@ static void acm_port_shutdown(struct tty_port *port)
 		urb = usb_get_from_anchor(&acm->delayed);
 		if (!urb)
 			break;
+		usb_put_urb(urb);
 		wb = urb->context;
 		wb->use = false;
 		usb_autopm_put_interface_async(acm->control);
@@ -1705,7 +1706,7 @@ static int acm_resume(struct usb_interface *intf)
 			urb = usb_get_from_anchor(&acm->delayed);
 			if (!urb)
 				break;
-
+			usb_put_urb(urb);
 			acm_start_wb(acm, urb->context);
 		}
 
-- 
2.55.0

Re: [PATCH] USB: cdc-acm: fix urb leak on disconnect

[sashiko-bot]

> Make sure to drop the reference taken by usb_anchor_urb() when removing
> URBs from the delayed URB anchor to prevent them from leaking when the
> device is later disconnected.
> 
> Fixes: 140cb81ac8c6 ("USB: cdc-acm: fix broken runtime suspend")
> Reported-by: Wentao Liang <vulab@iscas.ac.cn>
> Link: https://lore.kernel.org/20260917161217.2161883-1-vulab@iscas.ac.cn/
> Cc: stable@vger.kernel.org	# 3.16
> Signed-off-by: Johan Hovold <johan@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261009122934.464142-1-johan@kernel.org?part=1