svn commit: r294879 - head/sys/netpfil/ipfw

[Luigi Rizzo]

Author: luigi
Date: Wed Jan 27 02:08:30 2016
New Revision: 294879
URL: https://svnweb.freebsd.org/changeset/base/294879

Log:
  bugfix: the scheduler template (dn_schk) for the round robin scheduler
  is followed by another structure (rr_schk) whose size must be set
  in the schk_datalen field of the descriptor.
  Not allocating the memory may cause other memory to be overwritten
  (though dn_schk is 192 bytes and rr_schk only 12 so we may be lucky
  and end up in the padding after the dn_schk).
  
  This is a merge candidate for stable and 10.3
  
  MFC after:	3 days

Modified:
  head/sys/netpfil/ipfw/dn_sched_rr.c

Modified: head/sys/netpfil/ipfw/dn_sched_rr.c
==============================================================================
--- head/sys/netpfil/ipfw/dn_sched_rr.c	Wed Jan 27 01:33:26 2016	(r294878)
+++ head/sys/netpfil/ipfw/dn_sched_rr.c	Wed Jan 27 02:08:30 2016	(r294879)
@@ -294,7 +294,7 @@ static struct dn_alg rr_desc = {
 	_SI( .name = ) "RR",
 	_SI( .flags = ) DN_MULTIQUEUE,
 
-	_SI( .schk_datalen = ) 0,
+	_SI( .schk_datalen = ) sizeof(struct rr_schk),
 	_SI( .si_datalen = ) sizeof(struct rr_si),
 	_SI( .q_datalen = ) sizeof(struct rr_queue) - sizeof(struct dn_queue),
 
@@ -311,5 +311,6 @@ static struct dn_alg rr_desc = {
 	_SI( .free_queue = ) rr_free_queue,
 };
 
+_Static_assert(sizeof(struct dn_schk) < 193, "a");
 
 DECLARE_DNSCHED_MODULE(dn_rr, &rr_desc);