sch_sfq: fix null pointer dereference on init failure

Currently only a memory allocation failure can lead to this, so let's
initialize the timer first.

Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 82469ef9655eb65431477215bb2df0fb2737f905..fc69fc5956e9d4d2dbfe645e4c25e83328517371 100644 (file)
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -716,13 +716,13 @@ static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
        int i;
        int err;
 
+       setup_deferrable_timer(&q->perturb_timer, sfq_perturbation,
+                              (unsigned long)sch);
+
        err = tcf_block_get(&q->block, &q->filter_list);
        if (err)
                return err;
 
-       setup_deferrable_timer(&q->perturb_timer, sfq_perturbation,
-                              (unsigned long)sch);
-
        for (i = 0; i < SFQ_MAX_DEPTH + 1; i++) {
                q->dep[i].next = i + SFQ_MAX_FLOWS;
                q->dep[i].prev = i + SFQ_MAX_FLOWS;