net_sched: reset pointers to tcf blocks in classful qdiscs' destructors

Traffic filters could keep direct pointers to classes in classful qdisc,
thus qdisc destruction first removes all filters before freeing classes.
Class destruction methods also tries to free attached filters but now
this isn't safe because tcf_block_put() unlike to tcf_destroy_chain()
cannot be called second time.

This patch set class->block to NULL after first tcf_block_put() and
turn second call into no-op.

Fixes: 6529eaba33 ("net: sched: introduce tcf block infractructure")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Konstantin Khlebnikov 2017-08-15 16:35:21 +03:00 committed by David S. Miller
parent 187e5b3ac8
commit 898904226b
4 changed files with 12 additions and 4 deletions

View File

@ -572,8 +572,10 @@ static void atm_tc_destroy(struct Qdisc *sch)
struct atm_flow_data *flow, *tmp;
pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
list_for_each_entry(flow, &p->flows, list)
list_for_each_entry(flow, &p->flows, list) {
tcf_block_put(flow->block);
flow->block = NULL;
}
list_for_each_entry_safe(flow, tmp, &p->flows, list) {
if (flow->ref > 1)

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@ -1431,8 +1431,10 @@ static void cbq_destroy(struct Qdisc *sch)
* be bound to classes which have been destroyed already. --TGR '04
*/
for (h = 0; h < q->clhash.hashsize; h++) {
hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode)
hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
tcf_block_put(cl->block);
cl->block = NULL;
}
}
for (h = 0; h < q->clhash.hashsize; h++) {
hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],

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@ -1530,8 +1530,10 @@ hfsc_destroy_qdisc(struct Qdisc *sch)
unsigned int i;
for (i = 0; i < q->clhash.hashsize; i++) {
hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode) {
tcf_block_put(cl->block);
cl->block = NULL;
}
}
for (i = 0; i < q->clhash.hashsize; i++) {
hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],

View File

@ -1258,8 +1258,10 @@ static void htb_destroy(struct Qdisc *sch)
tcf_block_put(q->block);
for (i = 0; i < q->clhash.hashsize; i++) {
hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode)
hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
tcf_block_put(cl->block);
cl->block = NULL;
}
}
for (i = 0; i < q->clhash.hashsize; i++) {
hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],