pkt_sched: cls_u32: Fix locking in u32_change()

New nodes are inserted in u32_change() under rtnl_lock() with wmb(), so without tcf_tree_lock() like in other classifiers (e.g. cls_fw). This isn't enough without rmb() on the read side, but on the other hand adding such barriers doesn't give any savings, so the lock is added instead. Reported-by: m0sia <m0sia@plotinka.ru> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>

pkt_sched: cls_u32: Fix locking in u32_change()
New nodes are inserted in u32_change() under rtnl_lock() with wmb(), so without tcf_tree_lock() like in other classifiers (e.g. cls_fw). This isn't enough without rmb() on the read side, but on the other hand adding such barriers doesn't give any savings, so the lock is added instead. Reported-by: m0sia <m0sia@plotinka.ru> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Jarek Poplawski · David S. Miller
1 parent f1d3e4dca3
Showing 1 changed file with 2 additions and 1 deletions Side-by-side Diff
net/sched/cls_u32.c
@@ -638,8 +638,9 @@
 				break;
  
 		n->next = *ins;
-		wmb();
+		tcf_tree_lock(tp);
 		*ins = n;
+		tcf_tree_unlock(tp);
  
 		*arg = (unsigned long)n;
 		return 0;
...	...	@@ -638,8 +638,9 @@
638	638	break;
639	639
640	640	n->next = *ins;
641		- wmb();
	641	+ tcf_tree_lock(tp);
642	642	*ins = n;
	643	+ tcf_tree_unlock(tp);
643	644
644	645	*arg = (unsigned long)n;
645	646	return 0;