4.20-stable review patch. If anyone has any objections, please let me know.
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From: Petr Machata petrm@mellanox.com
[ Upstream commit c1f7e02979edd7a3a3e69fe04be60b1d650dc8a7 ]
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 Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/cls_flower.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/net/sched/cls_flower.c +++ b/net/sched/cls_flower.c @@ -1257,7 +1257,7 @@ static int fl_change(struct net *net, st 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)) @@ -1287,6 +1287,10 @@ static int fl_change(struct net *net, st 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);