From: Xiyu Yang xiyuyang19@fudan.edu.cn
stable inclusion from linux-4.19.207 commit 5129766a9797ea212087314fafc68268f1bf8515
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[ Upstream commit c66070125837900163b81a03063ddd657a7e9bfb ]
The reference counting issue happens in one exception handling path of cbq_change_class(). When failing to get tcf_block, the function forgets to decrease the refcount of "rtab" increased by qdisc_put_rtab(), causing a refcount leak.
Fix this issue by jumping to "failure" label when get tcf_block failed.
Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure") Signed-off-by: Xiyu Yang xiyuyang19@fudan.edu.cn Reviewed-by: Cong Wang cong.wang@bytedance.com Link: https://lore.kernel.org/r/1630252681-71588-1-git-send-email-xiyuyang19@fudan... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- net/sched/sch_cbq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c index ebc3c8c7e6661..bc62e1b246539 100644 --- a/net/sched/sch_cbq.c +++ b/net/sched/sch_cbq.c @@ -1616,7 +1616,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack); if (err) { kfree(cl); - return err; + goto failure; }
if (tca[TCA_RATE]) {