svn commit: r336426 - head/sys/dev/hyperv/netvsc

[Dexuan Cui]

Author: dexuan
Date: Tue Jul 17 21:05:08 2018
New Revision: 336426
URL: https://svnweb.freebsd.org/changeset/base/336426

Log:
  hyperv/hn: Fix panic in hypervisor code upon device detach event
  
  Submitted by:	hselasky
  Reviewed by:	dexuan
  MFC after:	3 days
  Differential Revision:	https://reviews.freebsd.org/D16139

Modified:
  head/sys/dev/hyperv/netvsc/if_hn.c

Modified: head/sys/dev/hyperv/netvsc/if_hn.c
==============================================================================
--- head/sys/dev/hyperv/netvsc/if_hn.c	Tue Jul 17 20:26:17 2018	(r336425)
+++ head/sys/dev/hyperv/netvsc/if_hn.c	Tue Jul 17 21:05:08 2018	(r336426)
@@ -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);