[PATCH 5.4 25/30] usbnet: Fix memory leak in usbnet_disconnect()

From: Greg Kroah-Hartman
Date: Mon Oct 03 2022 - 04:13:52 EST


From: Peilin Ye <peilin.ye@xxxxxxxxxxxxx>

[ Upstream commit a43206156263fbaf1f2b7f96257441f331e91bb7 ]

Currently usbnet_disconnect() unanchors and frees all deferred URBs
using usb_scuttle_anchored_urbs(), which does not free urb->context,
causing a memory leak as reported by syzbot.

Use a usb_get_from_anchor() while loop instead, similar to what we did
in commit 19cfe912c37b ("Bluetooth: btusb: Fix memory leak in
play_deferred"). Also free urb->sg.

Reported-and-tested-by: syzbot+dcd3e13cf4472f2e0ba1@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 69ee472f2706 ("usbnet & cdc-ether: Autosuspend for online devices")
Fixes: 638c5115a794 ("USBNET: support DMA SG")
Signed-off-by: Peilin Ye <peilin.ye@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220923042551.2745-1-yepeilin.cs@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/usb/usbnet.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 7a8324d2a968..7af8c3a8f3f1 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1585,6 +1585,7 @@ void usbnet_disconnect (struct usb_interface *intf)
struct usbnet *dev;
struct usb_device *xdev;
struct net_device *net;
+ struct urb *urb;

dev = usb_get_intfdata(intf);
usb_set_intfdata(intf, NULL);
@@ -1601,7 +1602,11 @@ void usbnet_disconnect (struct usb_interface *intf)
net = dev->net;
unregister_netdev (net);

- usb_scuttle_anchored_urbs(&dev->deferred);
+ while ((urb = usb_get_from_anchor(&dev->deferred))) {
+ dev_kfree_skb(urb->context);
+ kfree(urb->sg);
+ usb_free_urb(urb);
+ }

if (dev->driver_info->unbind)
dev->driver_info->unbind (dev, intf);
--
2.35.1