From: Xuanqiang Luo <[email protected]>

A batched RTM_DELACTION request takes a temporary reference on each
action before attempting any deletion. tcf_action_delete() clears
each processed slot and drops its temporary reference before attempting
the deletion. If deletion fails, tca_action_gd() calls
tcf_action_put_many() to release the remaining references, but its
tcf_act_for_each_action() iterator stops at the first NULL slot.

When a batch stops at an action bound to a filter, this leaks a
reference on each subsequent action. A later delete of an unbound
action can then return success without removing it from the IDR.

Walk the full array in tcf_action_put_many() and skip NULL slots to
release the references held on the unprocessed actions.

Fixes: a0e947c9ccff ("net/sched: act_api: avoid non-contiguous action array")
Cc: [email protected]
Signed-off-by: Xuanqiang Luo <[email protected]>
---
 net/sched/act_api.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 37eced84dfa5f..86710a596a0fa 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -1223,11 +1223,16 @@ static int tcf_action_put(struct tc_action *p)
 
 static void tcf_action_put_many(struct tc_action *actions[])
 {
-       struct tc_action *a;
        int i;
 
-       tcf_act_for_each_action(i, a, actions) {
-               const struct tc_action_ops *ops = a->ops;
+       /* Deletion may have cleared entries before failing. */
+       for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
+               struct tc_action *a = actions[i];
+               const struct tc_action_ops *ops;
+
+               if (!a)
+                       continue;
+               ops = a->ops;
                if (tcf_action_put(a))
                        module_put(ops->owner);
        }
-- 
2.43.0


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