From c1f7e02979edd7a3a3e69fe04be60b1d650dc8a7 Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Mon, 4 Feb 2019 14:50:38 +0000 Subject: [PATCH] net: cls_flower: Remove filter from mask before freeing it 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 Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller --- net/sched/cls_flower.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) 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); -- GitLab