In commit 92833e8b5db6c209e9311ac8c6a44d3bf1856659 titled "net: sched: rename qdisc_destroy() to qdisc_put()" part of the functionality of qdisc_destroy() was moved into a (for linux-4.19.y) new function qdisk_put(), and the previous calls to qdisc_destroy() were changed to qdisk_put(). This made it similar to f.e. 5.10.y and current master.

There was one part of qdisc_destroy() not moved over to qdisc_put() and that was the check for a NULL pointer, causing oopses. (See upstream commit: 6efb971ba8edfbd80b666f29de12882852f095ae) This patch fixes that.

Fixes: 92833e8b5db6c209e9311ac8c6a44d3bf1856659 Reported-by: Thorsten Glaser tg@mirbsd.de Link: https://bugs.debian.org/1013299 Signed-off-by: Diederik de Haas didi.debian@cknow.org --- net/sched/sch_generic.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 7c1b1eff84f4..cad2586c3473 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -970,8 +970,6 @@ static void qdisc_destroy(struct Qdisc *qdisc) const struct Qdisc_ops *ops; struct sk_buff *skb, *tmp;

- if (!qdisc) - return; ops = qdisc->ops;

#ifdef CONFIG_NET_SCHED @@ -1003,6 +1001,9 @@ static void qdisc_destroy(struct Qdisc *qdisc)

void qdisc_put(struct Qdisc *qdisc) { + if (!qdisc) + return; + if (qdisc->flags & TCQ_F_BUILTIN || !refcount_dec_and_test(&qdisc->refcnt)) return;