Commit 244b65db authored Apr 15, 2012 by David Ward Committed by David S. Miller Apr 16, 2012

net_sched: gred: Fix oops in gred_dump() in WRED mode

A parameter set exists for WRED mode, called wred_set, to hold the same
values for qavg and qidlestart across all VQs. The WRED mode values had
been previously held in the VQ for the default DP. After these values
were moved to wred_set, the VQ for the default DP was no longer created
automatically (so that it could be omitted on purpose, to have packets
in the default DP enqueued directly to the device without using RED).

However, gred_dump() was overlooked during that change; in WRED mode it
still reads qavg/qidlestart from the VQ for the default DP, which might
not even exist. As a result, this command sequence will cause an oops:

tc qdisc add dev $DEV handle $HANDLE parent $PARENT gred setup \
DPs 3 default 2 grio
tc qdisc change dev $DEV handle $HANDLE gred DP 0 prio 8 $RED_OPTIONS
tc qdisc change dev $DEV handle $HANDLE gred DP 1 prio 8 $RED_OPTIONS

This fixes gred_dump() in WRED mode to use the values held in wred_set.

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a49bcabe

net/sched/sch_gred.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -565,11 +565,8 @@ static int gred_dump(struct Qdisc sch, struct sk_buff skb)
		opt.packets = q->packetsin;
		opt.bytesin = q->bytesin;

		if (gred_wred_mode(table)) {
		q->vars.qidlestart =
		table->tab[table->def]->vars.qidlestart;
		q->vars.qavg = table->tab[table->def]->vars.qavg;
		}
		if (gred_wred_mode(table))
		gred_load_wred_set(table, q);

		opt.qave = red_calc_qavg(&q->parms, &q->vars, q->vars.qavg);

Admin message