| Message ID | 6f8e5a3f3ad2d6bc2f5a81ce1be1167b8aa456df.1549291065.git.petrm@mellanox.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] net: cls_flower: Remove filter from mask before freeing it | expand |
From: Petr Machata <petrm@mellanox.com> Date: Mon, 4 Feb 2019 14:50:38 +0000 > In fl_change(), when adding a new rule (i.e. fold == NULL), a driver may > reject the new rule, for example due to resource exhaustion. By that > point, the new rule was already assigned a mask, and it was added to > that mask's hash table. The clean-up path that's invoked as a result of > the rejection however neglects to undo the hash table addition, and > proceeds to free the new rule, thus leaving a dangling pointer in the > hash table. > > Fix by removing fnew from the mask's hash table before it is freed. > > Fixes: 35cc3cefc4de ("net/sched: cls_flower: Reject duplicated rules > also under skip_sw") Please do not break up lone Fixes: tag lines in the future, I fixed it up for you this time. > Signed-off-by: Petr Machata <petrm@mellanox.com> > Acked-by: Jiri Pirko <jiri@mellanox.com> > Reviewed-by: Ido Schimmel <idosch@mellanox.com> Applied and queued up for -stable.
David Miller <davem@davemloft.net> writes: > From: Petr Machata <petrm@mellanox.com> > Date: Mon, 4 Feb 2019 14:50:38 +0000 > >> In fl_change(), when adding a new rule (i.e. fold == NULL), a driver may >> reject the new rule, for example due to resource exhaustion. By that >> point, the new rule was already assigned a mask, and it was added to >> that mask's hash table. The clean-up path that's invoked as a result of >> the rejection however neglects to undo the hash table addition, and >> proceeds to free the new rule, thus leaving a dangling pointer in the >> hash table. >> >> Fix by removing fnew from the mask's hash table before it is freed. >> >> Fixes: 35cc3cefc4de ("net/sched: cls_flower: Reject duplicated rules >> also under skip_sw") > > Please do not break up lone Fixes: tag lines in the future, I fixed it > up for you this time. Sorry about that and thanks.
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c index f6aa57fbbbaf..12ca9d13db83 100644 --- a/net/sched/cls_flower.c +++ b/net/sched/cls_flower.c @@ -1371,7 +1371,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb, if (!tc_skip_hw(fnew->flags)) { err = fl_hw_replace_filter(tp, fnew, extack); if (err) - goto errout_mask; + goto errout_mask_ht; } if (!tc_in_hw(fnew->flags)) @@ -1401,6 +1401,10 @@ static int fl_change(struct net *net, struct sk_buff *in_skb, kfree(mask); return 0; +errout_mask_ht: + rhashtable_remove_fast(&fnew->mask->ht, &fnew->ht_node, + fnew->mask->filter_ht_params); + errout_mask: fl_mask_put(head, fnew->mask, false);
In fl_change(), when adding a new rule (i.e. fold == NULL), a driver may reject the new rule, for example due to resource exhaustion. By that point, the new rule was already assigned a mask, and it was added to that mask's hash table. The clean-up path that's invoked as a result of the rejection however neglects to undo the hash table addition, and proceeds to free the new rule, thus leaving a dangling pointer in the hash table. Fix by removing fnew from the mask's hash table before it is freed. Fixes: 35cc3cefc4de ("net/sched: cls_flower: Reject duplicated rules also under skip_sw") Signed-off-by: Petr Machata <petrm@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> --- Notes: Note that this is covered by mirror_gre_scale test in tools/testing/selftests/drivers/net/mlxsw/spectrum/resource_scale.sh net/sched/cls_flower.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)