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authorBjørn Mork <bjorn@mork.no>2017-11-06 15:37:22 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-11-21 09:21:18 +0100
commitcaeeef8438c30e7d0e43293fcb7beb9f953bb2a9 (patch)
tree45cd5da4b1f5aa754b1fc8ec4d58d47f135acf4c
parent46bdabbca02ebabd292d0ea3f610aa54e53f0e25 (diff)
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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> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/usb/cdc_ether.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 8c408aa2f208..f9343bee1de3 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -221,7 +221,7 @@ 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.