svn commit: r304163 - stable/11/sys/dev/bxe

[Ryan Stone]

Author: rstone
Date: Mon Aug 15 15:23:45 2016
New Revision: 304163
URL: https://svnweb.freebsd.org/changeset/base/304163

Log:
  MFC r303836
  
    Don't enqueue NULL on a drbr
  
    In one corner case in the bxe TX path, a NULL mbuf could be enqueued onto
    a drbr queue.  This could case a KASSERT to fire with INVARIANTS enabled,
    or the processing of packets from the queue to be prematurely ended later
    on.
  
    Submitted by: Matt Joras (matt.joras AT isilon.com)
    Reviewed by:  davidcs
    Sponsored by: EMC / Isilon Storage Division
    Differential Revision:        https://reviews.freebsd.org/D7041

Modified:
  stable/11/sys/dev/bxe/bxe.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/dev/bxe/bxe.c
==============================================================================
--- stable/11/sys/dev/bxe/bxe.c	Mon Aug 15 14:58:25 2016	(r304162)
+++ stable/11/sys/dev/bxe/bxe.c	Mon Aug 15 15:23:45 2016	(r304163)
@@ -5624,7 +5624,8 @@ bxe_tx_mq_start_locked(struct bxe_softc 
     if (!sc->link_vars.link_up ||
         (if_getdrvflags(ifp) &
         (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) != IFF_DRV_RUNNING) {
-        rc = drbr_enqueue(ifp, tx_br, m);
+        if (m != NULL)
+            rc = drbr_enqueue(ifp, tx_br, m);
         goto bxe_tx_mq_start_locked_exit;
     }