fq_codel: fix TCA_FQ_CODEL_DROP_BATCH_SIZE sanity checks

stable inclusion
from linux-4.19.123
commit d10f7717357dd5397878660af04aae3efe258e13

--------------------------------

[ Upstream commit 14695212 ]

My intent was to not let users set a zero drop_batch_size,
it seems I once again messed with min()/max().

Fixes: 9d18562a ("fq_codel: add batch ability to fq_codel_drop()")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NLi Aichun <liaichun@huawei.com>
Reviewed-by: Nguodeqing <geffrey.guo@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/sched/sch_fq_codel.c

@@ -429,7 +429,7 @@ static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt,
 		q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
 
 	if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])
-		q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]));
+		q->drop_batch_size = max(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]));
 
 	if (tb[TCA_FQ_CODEL_MEMORY_LIMIT])
 		q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT]));