Commit e8d3d78c authored Jul 13, 2023 by Victor Nogueira Committed by David S. Miller Jul 17, 2023

net: sched: cls_u32: Undo refcount decrement in case update failed



In the case of an update, when TCA_U32_LINK is set, u32_set_parms will
decrement the refcount of the ht_down (struct tc_u_hnode) pointer
present in the older u32 filter which we are replacing. However, if
u32_replace_hw_knode errors out, the update command fails and that
ht_down pointer continues decremented. To fix that, when
u32_replace_hw_knode fails, check if ht_down's refcount was decremented
and undo the decrement.

Fixes: d34e3e18 ("net: cls_u32: Add support for skip-sw flag to tc u32 classifier.")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 9cb36fae

net/sched/cls_u32.c

+7 −0

Original line number	Original line	Diff line number	Diff line
	@@ -928,6 +928,13 @@ static int u32_change(struct net net, struct sk_buff in_skb,
	if (err) {		if (err) {
	u32_unbind_filter(tp, new, tb);		u32_unbind_filter(tp, new, tb);

			if (tb[TCA_U32_LINK]) {
			struct tc_u_hnode *ht_old;

			ht_old = rtnl_dereference(n->ht_down);
			if (ht_old)
			ht_old->refcnt++;
			}
	__u32_destroy_key(new);		__u32_destroy_key(new);
	return err;		return err;
	}		}