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authorOliver Neukum <oneukum@suse.com>2019-09-19 11:23:08 +0300
committerDavid S. Miller <davem@davemloft.net>2019-09-19 14:27:11 +0300
commit280ceaed79f18db930c0cc8bb21f6493490bf29c (patch)
treeedbf7f8852963bf643f54508afe877c5cec46857
parentb41dae061bbd722b9d7fa828f35d22035b218e18 (diff)
downloadlinux-280ceaed79f18db930c0cc8bb21f6493490bf29c.tar.xz
usbnet: sanity checking of packet sizes and device mtu
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>
-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 58952a79b05f..e44849499b89 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -339,6 +339,8 @@ 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;
@@ -355,6 +357,7 @@ 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;
}
}