From 2cb80187ba065d7decad7c6614e35e07aec8a974 Mon Sep 17 00:00:00 2001 From: Bjørn Mork Date: Mon, 6 Nov 2017 15:37:22 +0100 Subject: net: cdc_ether: fix divide by 0 on bad descriptors Setting dev->hard_mtu to 0 will cause a divide error in usbnet_probe. Protect against devices with bogus CDC Ethernet functional descriptors by ignoring a zero wMaxSegmentSize. Signed-off-by: Bjørn Mork Acked-by: Oliver Neukum Signed-off-by: David S. Miller --- drivers/net/usb/cdc_ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/usb') diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c index 3e7a3ac3a362..05dca3e5c93d 100644 --- a/drivers/net/usb/cdc_ether.c +++ b/drivers/net/usb/cdc_ether.c @@ -230,7 +230,7 @@ skip: goto bad_desc; } - if (header.usb_cdc_ether_desc) { + if (header.usb_cdc_ether_desc && info->ether->wMaxSegmentSize) { dev->hard_mtu = le16_to_cpu(info->ether->wMaxSegmentSize); /* because of Zaurus, we may be ignoring the host * side link address we were given. -- cgit v1.2.3-55-g7522