diff options
| author | Bjørn Mork <bjorn@mork.no> | 2017-11-06 15:37:22 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-11-26 13:51:11 +0000 |
| commit | d7d24810ac55e2f3fb213d6acf80016a0d337c50 (patch) | |
| tree | f8364ad886f9f76c8628a55b1ae1d181c53f6703 | |
| parent | 2de544fd1b16f76f8dd1213d585ce611155ccd34 (diff) | |
net: cdc_ether: fix divide by 0 on bad descriptors
commit 2cb80187ba065d7decad7c6614e35e07aec8a974 upstream.
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 <bjorn@mork.no>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: parsing code is organised differently]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/net/usb/cdc_ether.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c index 43aa06b3f7c6..a1ca4745d706 100644 --- a/drivers/net/usb/cdc_ether.c +++ b/drivers/net/usb/cdc_ether.c @@ -234,8 +234,9 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) info->ether->bLength); goto bad_desc; } - dev->hard_mtu = le16_to_cpu( - info->ether->wMaxSegmentSize); + if (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. */ |