tree c5b99bd44f94a5e6094869c8da1f0683e0777a02
parent 10e2eb878f3ca07ac2f05fa5ca5e6c4c9174a27a
author Ross Lagerwall <ross.lagerwall@citrix.com> 1438612683 +0100
committer David S. Miller <davem@davemloft.net> 1438665783 -0700

xen-netback: Allocate fraglist early to avoid complex rollback

Determine if a fraglist is needed in the tx path, and allocate it if
necessary before setting up the copy and map operations.
Otherwise, undoing the copy and map operations is tricky.

This fixes a use-after-free: if allocating the fraglist failed, the copy
and map operations that had been set up were still executed, writing
over the data area of a freed skb.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>