svn commit: r336643 - stable/11/sys/dev/hyperv/netvsc

[Dexuan Cui]

Author: dexuan
Date: Mon Jul 23 17:35:20 2018
New Revision: 336643
URL: https://svnweb.freebsd.org/changeset/base/336643

Log:
  MFC: 336426
  
      r336426
          hyperv/hn: Fix panic in hypervisor code upon device detach event
  
          Submitted by:       hselasky
          Reviewed by:        dexuan
          Differential Revision:      https://reviews.freebsd.org/D16139

Modified:
  stable/11/sys/dev/hyperv/netvsc/if_hn.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/dev/hyperv/netvsc/if_hn.c
==============================================================================
--- stable/11/sys/dev/hyperv/netvsc/if_hn.c	Mon Jul 23 17:26:38 2018	(r336642)
+++ stable/11/sys/dev/hyperv/netvsc/if_hn.c	Mon Jul 23 17:35:20 2018	(r336643)
@@ -1161,6 +1161,13 @@ hn_ismyvf(const struct hn_softc *sc, const struct ifne
 	    strcmp(ifp->if_dname, "vlan") == 0)
 		return (false);
 
+	/*
+	 * During detach events ifp->if_addr might be NULL.
+	 * Make sure the bcmp() below doesn't panic on that:
+	 */
+	if (ifp->if_addr == NULL || hn_ifp->if_addr == NULL)
+		return (false);
+
 	if (bcmp(IF_LLADDR(ifp), IF_LLADDR(hn_ifp), ETHER_ADDR_LEN) != 0)
 		return (false);