6.11-stable review patch. If anyone has any objections, please let me know.
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From: Alexandre Ferrieux alexandre.ferrieux@gmail.com
[ 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@google.com Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Alexandre Ferrieux alexandre.ferrieux@orange.com Tested-by: Victor Nogueira victor@mojatatu.com Link: https://patch.msgid.link/20241110172836.331319-1-alexandre.ferrieux@orange.c... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 9412d88a99bc1..d3a03c57545bc 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -92,6 +92,16 @@ 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) @@ -310,7 +320,7 @@ 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; @@ -360,7 +370,7 @@ 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); @@ -612,7 +622,7 @@ 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; @@ -989,7 +999,7 @@ 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; }