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authorOliver Neukum <oneukum@suse.com>2019-09-19 10:23:08 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-05 12:30:14 +0200
commit55416208602b20a5079a75dbef901feb8f1e9c69 (patch)
tree8aa9d0c8d904ef369bfc87fb9e24e54785ec6fdf
parent96f23cb83539bb569a02b5524a62c18c7b8c40e2 (diff)
usbnet: sanity checking of packet sizes and device mtu
[ Upstream commit 280ceaed79f18db930c0cc8bb21f6493490bf29c ] After a reset packet sizes and device mtu can change and need to be reevaluated to calculate queue sizes. Malicious devices can set this to zero and we divide by it. Introduce sanity checking. Reported-and-tested-by: syzbot+6102c120be558c885f04@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/usb/usbnet.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 6d0efeb28f5c..0b5fd1499ac0 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -354,6 +354,8 @@ void usbnet_update_max_qlen(struct usbnet *dev)
{
enum usb_device_speed speed = dev->udev->speed;
+ if (!dev->rx_urb_size || !dev->hard_mtu)
+ goto insanity;
switch (speed) {
case USB_SPEED_HIGH:
dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
@@ -370,6 +372,7 @@ void usbnet_update_max_qlen(struct usbnet *dev)
dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
break;
default:
+insanity:
dev->rx_qlen = dev->tx_qlen = 4;
}
}