6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexandre Ferrieux <alexandre.ferrieux@xxxxxxxxx>
[ Upstream commit 73af53d82076bbe184d9ece9e14b0dc8599e6055 ]
To generate hnode handles (in gen_new_htid()), u32 uses IDR and
encodes the returned small integer into a structured 32-bit
word. Unfortunately, at disposal time, the needed decoding
is not done. As a result, idr_remove() fails, and the IDR
fills up. Since its size is 2048, the following script ends up
with "Filter already exists":
tc filter add dev myve $FILTER1
tc filter add dev myve $FILTER2
for i in {1..2048}
do
echo $i
tc filter del dev myve $FILTER2
tc filter add dev myve $FILTER2
done
This patch adds the missing decoding logic for handles that
deserve it.
Fixes: e7614370d6f0 ("net_sched: use idr to allocate u32 filter handles")
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Signed-off-by: Alexandre Ferrieux <alexandre.ferrieux@xxxxxxxxxx>
Tested-by: Victor Nogueira <victor@xxxxxxxxxxxx>
Link: https://patch.msgid.link/20241110172836.331319-1-alexandre.ferrieux@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sched/cls_u32.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index adcc8de1d01be..e87d79d043d54 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -91,6 +91,16 @@ struct tc_u_common {
long knodes;
};
+static u32 handle2id(u32 h)
+{
+ return ((h & 0x80000000) ? ((h >> 20) & 0x7FF) : h);
+}
+
+static u32 id2handle(u32 id)
+{
+ return (id | 0x800U) << 20;
+}
+
static inline unsigned int u32_hash_fold(__be32 key,
const struct tc_u32_sel *sel,
u8 fshift)
@@ -308,7 +318,7 @@ static u32 gen_new_htid(struct tc_u_common *tp_c, struct tc_u_hnode *ptr)
int id = idr_alloc_cyclic(&tp_c->handle_idr, ptr, 1, 0x7FF, GFP_KERNEL);
if (id < 0)
return 0;
- return (id | 0x800U) << 20;
+ return id2handle(id);
}
static struct hlist_head *tc_u_common_hash;
@@ -358,7 +368,7 @@ static int u32_init(struct tcf_proto *tp)
return -ENOBUFS;
refcount_set(&root_ht->refcnt, 1);
- root_ht->handle = tp_c ? gen_new_htid(tp_c, root_ht) : 0x80000000;
+ root_ht->handle = tp_c ? gen_new_htid(tp_c, root_ht) : id2handle(0);
root_ht->prio = tp->prio;
root_ht->is_root = true;
idr_init(&root_ht->handle_idr);
@@ -610,7 +620,7 @@ static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht,
if (phn == ht) {
u32_clear_hw_hnode(tp, ht, extack);
idr_destroy(&ht->handle_idr);
- idr_remove(&tp_c->handle_idr, ht->handle);
+ idr_remove(&tp_c->handle_idr, handle2id(ht->handle));
RCU_INIT_POINTER(*hn, ht->next);
kfree_rcu(ht, rcu);
return 0;
@@ -987,7 +997,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
err = u32_replace_hw_hnode(tp, ht, userflags, extack);
if (err) {
- idr_remove(&tp_c->handle_idr, handle);
+ idr_remove(&tp_c->handle_idr, handle2id(handle));
kfree(ht);
return err;
}
--
2.43.0
