svn commit: r272965 - stable/10/sys/dev/ixgbe

[Adrian Chadd]

Author: adrian
Date: Sat Oct 11 22:08:53 2014
New Revision: 272965
URL: https://svnweb.freebsd.org/changeset/base/272965

Log:
  Merge r271647 - Fix a double-free of mbufs in rx_ixgbe_discard().
  
    fmp->buf at the free point is already part of the chain being freed,
    so double-freeing is counter-productive.
  
  Submitted by:	Marc De La Gueronniere <mdelagueronniere at verisign.com>
  Sponsored by:	Verisign, Inc.

Modified:
  stable/10/sys/dev/ixgbe/ixgbe.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/ixgbe/ixgbe.c
==============================================================================
--- stable/10/sys/dev/ixgbe/ixgbe.c	Sat Oct 11 21:54:23 2014	(r272964)
+++ stable/10/sys/dev/ixgbe/ixgbe.c	Sat Oct 11 22:08:53 2014	(r272965)
@@ -4368,11 +4368,6 @@ ixgbe_rx_discard(struct rx_ring *rxr, in
 
 	rbuf = &rxr->rx_buffers[i];
 
-        if (rbuf->fmp != NULL) {/* Partial chain ? */
-		rbuf->fmp->m_flags |= M_PKTHDR;
-                m_freem(rbuf->fmp);
-                rbuf->fmp = NULL;
-	}
 
 	/*
 	** With advanced descriptors the writeback
@@ -4381,7 +4376,13 @@ ixgbe_rx_discard(struct rx_ring *rxr, in
 	** the normal refresh path to get new buffers
 	** and mapping.
 	*/
-	if (rbuf->buf) {
+
+	if (rbuf->fmp != NULL) {/* Partial chain ? */
+		rbuf->fmp->m_flags |= M_PKTHDR;
+		m_freem(rbuf->fmp);
+		rbuf->fmp = NULL;
+		rbuf->buf = NULL; /* rbuf->buf is part of fmp's chain */
+	} else if (rbuf->buf) {
 		m_free(rbuf->buf);
 		rbuf->buf = NULL;
 	}