Description: net: cdc_ether: fix divide by 0 on bad descriptors 
References:
 https://patchwork.ozlabs.org/patch/834771/
Notes:
 bwh> Probably introduced in 2.6.19 by commit a99c19492a80 "USB: usbnet - Add
 bwh> unlink_rx_urbs() call to allow for Jumbo Frames".
Bugs:
upstream: released (4.14) [2cb80187ba065d7decad7c6614e35e07aec8a974]
4.9-upstream-stable: released (4.9.65) [f376621861e3d8a713d6931f4363c4137912330b]
3.16-upstream-stable: released (3.16.51) [fac4f4657e16d3457963d4c8ee6a356103155141]
3.2-upstream-stable: released (3.2.96) [d7d24810ac55e2f3fb213d6acf80016a0d337c50]
sid: released (4.13.13-1) [bugfix/all/net-cdc_ether-fix-divide-by-0-on-bad-descriptors.patch]
4.9-stretch-security: released (4.9.65-1)
3.16-jessie-security: released (3.16.51-1)
3.2-wheezy-security: released (3.2.96-1)