@@ -41,6 +41,16 @@
#include <linux/idr.h>
#include <net/tc_wrapper.h>
+static inline u32 handle2id(u32 h)
+{
+ return ((h & 0x80000000) ? ((h >> 20) & 0x7FF) : h);
+}
+
+static inline u32 id2handle(u32 id)
+{
+ return (id | 0x800U) << 20;
+}
+
struct tc_u_knode {
struct tc_u_knode __rcu *next;
u32 handle;
@@ -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;
}
@@ -329,5 +329,29 @@
"teardown": [
"$TC qdisc del dev $DEV1 parent root drr"
]
+ },
+ {
+ "id": "1234",
+ "name": "Exercise IDR leaks by creating/deleting a filter many (2048) times",
+ "category": [
+ "filter",
+ "u32"
+ ],
+ "plugins": {
+ "requires": "nsPlugin"
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 parent root handle 10: drr",
+ "$TC filter add dev $DEV1 parent 10:0 protocol ip prio 2 u32 match ip src 0.0.0.2/32 action drop",
+ "$TC filter add dev $DEV1 parent 10:0 protocol ip prio 3 u32 match ip src 0.0.0.3/32 action drop"
+ ],
+ "cmdUnderTest": "bash -c 'for i in {1..2048} ;do echo filter delete dev $DEV1 pref 3;echo filter add dev $DEV1 parent 10:0 protocol ip prio 3 u32 match ip src 0.0.0.3/32 action drop;done | $TC -b -'",
+ "expExitCode": "0",
+ "verifyCmd": "$TC filter show dev $DEV1",
+ "matchPattern": "protocol ip pref 3 u32",
+ "matchCount": "3",
+ "teardown": [
+ "$TC qdisc del dev $DEV1 parent root drr"
+ ]
}
]
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, along with a corresponding tdc test. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexandre Ferrieux <alexandre.ferrieux@orange.com> --- v6: big speedup of the tdc test with batch tc v5: fix title - again v4: add tdc test v3: prepend title with subsystem ident v2: use u32 type in handle encoder/decoder net/sched/cls_u32.c | 18 ++++++++++---- .../tc-testing/tc-tests/filters/u32.json | 24 +++++++++++++++++++ 2 files changed, 38 insertions(+), 4 deletions(-)