diff options
| author |   Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2017-08-15 16:35:21 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-08-15 17:16:39 -0700 |
| commit | 898904226b5a6dee657f23cf51e385f50da22596 (patch) | |
| tree | 1d05b77926120b605ee6ef71f3abe270a49c66e6 /net/sched/sch_htb.c | |
| parent | ipv4: fix NULL dereference in free_fib_info_rcu() (diff) | |
| download | linux-dev-898904226b5a6dee657f23cf51e385f50da22596.tar.xz linux-dev-898904226b5a6dee657f23cf51e385f50da22596.zip | |
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: 6529eaba33f0 ("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>
Diffstat (limited to 'net/sched/sch_htb.c')
| -rw-r--r-- | net/sched/sch_htb.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 203286ab4427..5d65ec5207e9 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -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], |