[ovs-git] [openvswitch/ovs] 7c3066: netdev-dpdk: Avoid undefined behavior processing d...

[Aaron Conole]

  Branch: refs/heads/branch-2.8
  Home:   https://github.com/openvswitch/ovs
  Commit: 7c3066bf02be03d60a5f7948c4a805191f1afa12
      https://github.com/openvswitch/ovs/commit/7c3066bf02be03d60a5f7948c4a805191f1afa12
  Author: Aaron Conole <aconole at redhat.com>
  Date:   2020-01-13 (Mon, 13 Jan 2020)

  Changed paths:
    M lib/netdev-dpdk.c

  Log Message:
  -----------
  netdev-dpdk: Avoid undefined behavior processing devargs

In "Use of library functions" in the C standard, the following statement
is written to apply to all library functions:

  If an argument to a function has an invalid value (such as ... a
  null pointer ... the behavior is undefined.

Later, under the "String handling" section, "Comparison functions" no
exception is listed for strcmp, which means NULL is invalid.  It may
be possible for the smap_get to return NULL.

Given the above, we must check that new_devargs is not null.  The check
against NULL for new_devargs later in the function is still valid.

Fixes: 55e075e65ef9 ("netdev-dpdk: Arbitrary 'dpdk' port naming")
Signed-off-by: Aaron Conole <aconole at redhat.com>
Acked-by: Ciara Loftus <ciara.loftus at intel.com>
Signed-off-by: Ian Stokes <ian.stokes at intel.com>