svn commit: r303848 - head/sys/netgraph

[Sean Bruno]

Author: sbruno
Date: Mon Aug  8 19:31:01 2016
New Revision: 303848
URL: https://svnweb.freebsd.org/changeset/base/303848

Log:
  Avoid panic from ng_uncallout when unpluggin ethernet cable with active
  PPTP VPN connection.
  
  Submitted by:	Michael Zhilin <mizhka at gmail.com>
  Reviewed by:	ngie
  MFC after:	3 days
  Differential Revision:	https://reviews.freebsd.org/D7209

Modified:
  head/sys/netgraph/ng_base.c

Modified: head/sys/netgraph/ng_base.c
==============================================================================
--- head/sys/netgraph/ng_base.c	Mon Aug  8 18:57:50 2016	(r303847)
+++ head/sys/netgraph/ng_base.c	Mon Aug  8 19:31:01 2016	(r303848)
@@ -3815,7 +3815,7 @@ ng_uncallout(struct callout *c, node_p n
 	item = c->c_arg;
 	/* Do an extra check */
 	if ((rval > 0) && (c->c_func == &ng_callout_trampoline) &&
-	    (NGI_NODE(item) == node)) {
+	    (item != NULL) && (NGI_NODE(item) == node)) {
 		/*
 		 * We successfully removed it from the queue before it ran
 		 * So now we need to unreference everything that was