From a43206156263fbaf1f2b7f96257441f331e91bb7 Mon Sep 17 00:00:00 2001
From: Peilin Ye <peilin.ye@bytedance.com>
Date: Thu, 22 Sep 2022 21:25:51 -0700
Subject: [PATCH] usbnet: Fix memory leak in usbnet_disconnect()
Git-commit: a43206156263fbaf1f2b7f96257441f331e91bb7
References: git-fixes
Patch-mainline: v6.0

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@syzkaller.appspotmail.com
Fixes: 69ee472f2706 ("usbnet & cdc-ether: Autosuspend for online devices")
Fixes: 638c5115a794 ("USBNET: support DMA SG")
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Link: https://lore.kernel.org/r/20220923042551.2745-1-yepeilin.cs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/usb/usbnet.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1594,6 +1594,7 @@ void usbnet_disconnect (struct usb_inter
 	struct usbnet		*dev;
 	struct usb_device	*xdev;
 	struct net_device	*net;
+	struct urb		*urb;
 
 	dev = usb_get_intfdata(intf);
 	usb_set_intfdata(intf, NULL);
@@ -1610,7 +1611,11 @@ void usbnet_disconnect (struct usb_inter
 	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);