pkt_sched: Fix sch_sfq vs tc_modify_qdisc oops

[ Upstream commit 41065fba846e795b31b17e4dec01cb904d56c6cd ]

sch_sfq as a classful qdisc needs the .leaf handler. Otherwise, there
is an oops possible in tc_modify_qdisc()/check_loop().

Fixes commit 7d2681a6ff4f9ab5e48d02550b4c6338f1638998

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 9616570b74bcc66a28643d22df137ef31554c5e6..d716d9b25ae71b5133d0e68be87065b56916eee2 100644 (file)
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -497,6 +497,11 @@ nla_put_failure:
        return -1;
 }
 
+static struct Qdisc *sfq_leaf(struct Qdisc *sch, unsigned long arg)
+{
+       return NULL;
+}
+
 static unsigned long sfq_get(struct Qdisc *sch, u32 classid)
 {
        return 0;
@@ -560,6 +565,7 @@ static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 }
 
 static const struct Qdisc_class_ops sfq_class_ops = {
+       .leaf           =       sfq_leaf,
        .get            =       sfq_get,
        .tcf_chain      =       sfq_find_tcf,
        .bind_tcf       =       sfq_bind,