svn commit: r308748 - head/sys/netgraph

[Bjoern A. Zeeb]

Author: bz
Date: Thu Nov 17 14:03:44 2016
New Revision: 308748
URL: https://svnweb.freebsd.org/changeset/base/308748

Log:
  Writing out the L2TP control packet requires 12 bytes of
  contiguous memory but in one path we did not always guarantee this,
  thus do a m_pullup() there.
  
  PR:			214385
  Submitted by:		Joe Jones (joeknockando googlemail.com)
  MFC after:		3 days

Modified:
  head/sys/netgraph/ng_l2tp.c

Modified: head/sys/netgraph/ng_l2tp.c
==============================================================================
--- head/sys/netgraph/ng_l2tp.c	Thu Nov 17 11:48:07 2016	(r308747)
+++ head/sys/netgraph/ng_l2tp.c	Thu Nov 17 14:03:44 2016	(r308748)
@@ -1544,6 +1544,16 @@ ng_l2tp_xmit_ctrl(priv_p priv, struct mb
 			priv->stats.memoryFailures++;
 			return (ENOBUFS);
 		}
+
+		/*
+		 * The below requires 12 contiguous bytes for the L2TP header
+		 * to be written into.
+		 */
+		m = m_pullup(m, 12);
+		if (m == NULL) {
+			priv->stats.memoryFailures++;
+			return (ENOBUFS);
+		}
 	}
 
 	/* Fill in L2TP header */