target/linux/generic/backport-4.14/342-v4.16-netfilter-nf_tables-fix-flowtable-free.patch

   1 From: Pablo Neira Ayuso <pablo@netfilter.org>
   2 Date: Mon, 5 Feb 2018 21:44:50 +0100
   3 Subject: [PATCH] netfilter: nf_tables: fix flowtable free
   4
   5 Every flow_offload entry is added into the table twice. Because of this,
   6 rhashtable_free_and_destroy can't be used, since it would call kfree for
   7 each flow_offload object twice.
   8
   9 This patch adds a call to nf_flow_table_iterate_cleanup() to schedule
  10 removal of entries, then there is an explicitly invocation of the
  11 garbage collector to clean up resources.
  12
  13 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
  14 ---
  15
  16 --- a/include/net/netfilter/nf_flow_table.h
  17 +++ b/include/net/netfilter/nf_flow_table.h
  18 @@ -14,6 +14,7 @@ struct nf_flowtable_type {
  19         struct list_head                list;
  20         int                             family;
  21         void                            (*gc)(struct work_struct *work);
  22 +       void                            (*free)(struct nf_flowtable *ft);
  23         const struct rhashtable_params  *params;
  24         nf_hookfn                       *hook;
  25         struct module                   *owner;
  26 @@ -98,6 +99,7 @@ int nf_flow_table_iterate(struct nf_flow
  27
  28  void nf_flow_table_cleanup(struct net *net, struct net_device *dev);
  29
  30 +void nf_flow_table_free(struct nf_flowtable *flow_table);
  31  void nf_flow_offload_work_gc(struct work_struct *work);
  32  extern const struct rhashtable_params nf_flow_offload_rhash_params;
  33
  34 --- a/net/ipv4/netfilter/nf_flow_table_ipv4.c
  35 +++ b/net/ipv4/netfilter/nf_flow_table_ipv4.c
  36 @@ -260,6 +260,7 @@ static struct nf_flowtable_type flowtabl
  37         .family         = NFPROTO_IPV4,
  38         .params         = &nf_flow_offload_rhash_params,
  39         .gc             = nf_flow_offload_work_gc,
  40 +       .free           = nf_flow_table_free,
  41         .hook           = nf_flow_offload_ip_hook,
  42         .owner          = THIS_MODULE,
  43  };
  44 --- a/net/ipv6/netfilter/nf_flow_table_ipv6.c
  45 +++ b/net/ipv6/netfilter/nf_flow_table_ipv6.c
  46 @@ -254,6 +254,7 @@ static struct nf_flowtable_type flowtabl
  47         .family         = NFPROTO_IPV6,
  48         .params         = &nf_flow_offload_rhash_params,
  49         .gc             = nf_flow_offload_work_gc,
  50 +       .free           = nf_flow_table_free,
  51         .hook           = nf_flow_offload_ipv6_hook,
  52         .owner          = THIS_MODULE,
  53  };
  54 --- a/net/netfilter/nf_flow_table.c
  55 +++ b/net/netfilter/nf_flow_table.c
  56 @@ -232,19 +232,16 @@ static inline bool nf_flow_is_dying(cons
  57         return flow->flags & FLOW_OFFLOAD_DYING;
  58  }
  59
  60 -void nf_flow_offload_work_gc(struct work_struct *work)
  61 +static int nf_flow_offload_gc_step(struct nf_flowtable *flow_table)
  62  {
  63         struct flow_offload_tuple_rhash *tuplehash;
  64 -       struct nf_flowtable *flow_table;
  65         struct rhashtable_iter hti;
  66         struct flow_offload *flow;
  67         int err;
  68
  69 -       flow_table = container_of(work, struct nf_flowtable, gc_work.work);
  70 -
  71         err = rhashtable_walk_init(&flow_table->rhashtable, &hti, GFP_KERNEL);
  72         if (err)
  73 -               goto schedule;
  74 +               return 0;
  75
  76         rhashtable_walk_start(&hti);
  77
  78 @@ -270,7 +267,16 @@ void nf_flow_offload_work_gc(struct work
  79  out:
  80         rhashtable_walk_stop(&hti);
  81         rhashtable_walk_exit(&hti);
  82 -schedule:
  83 +
  84 +       return 1;
  85 +}
  86 +
  87 +void nf_flow_offload_work_gc(struct work_struct *work)
  88 +{
  89 +       struct nf_flowtable *flow_table;
  90 +
  91 +       flow_table = container_of(work, struct nf_flowtable, gc_work.work);
  92 +       nf_flow_offload_gc_step(flow_table);
  93         queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
  94  }
  95  EXPORT_SYMBOL_GPL(nf_flow_offload_work_gc);
  96 @@ -449,5 +455,12 @@ void nf_flow_table_cleanup(struct net *n
  97  }
  98  EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
  99
 100 +void nf_flow_table_free(struct nf_flowtable *flow_table)
 101 +{
 102 +       nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
 103 +       WARN_ON(!nf_flow_offload_gc_step(flow_table));
 104 +}
 105 +EXPORT_SYMBOL_GPL(nf_flow_table_free);
 106 +
 107  MODULE_LICENSE("GPL");
 108  MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 109 --- a/net/netfilter/nf_flow_table_inet.c
 110 +++ b/net/netfilter/nf_flow_table_inet.c
 111 @@ -24,6 +24,7 @@ static struct nf_flowtable_type flowtabl
 112         .family         = NFPROTO_INET,
 113         .params         = &nf_flow_offload_rhash_params,
 114         .gc             = nf_flow_offload_work_gc,
 115 +       .free           = nf_flow_table_free,
 116         .hook           = nf_flow_offload_inet_hook,
 117         .owner          = THIS_MODULE,
 118  };
 119 --- a/net/netfilter/nf_tables_api.c
 120 +++ b/net/netfilter/nf_tables_api.c
 121 @@ -5292,17 +5292,12 @@ err:
 122         nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES, -ENOBUFS);
 123  }
 124
 125 -static void nft_flowtable_destroy(void *ptr, void *arg)
 126 -{
 127 -       kfree(ptr);
 128 -}
 129 -
 130  static void nf_tables_flowtable_destroy(struct nft_flowtable *flowtable)
 131  {
 132         cancel_delayed_work_sync(&flowtable->data.gc_work);
 133         kfree(flowtable->name);
 134 -       rhashtable_free_and_destroy(&flowtable->data.rhashtable,
 135 -                                   nft_flowtable_destroy, NULL);
 136 +       flowtable->data.type->free(&flowtable->data);
 137 +       rhashtable_destroy(&flowtable->data.rhashtable);
 138         module_put(flowtable->data.type->owner);
 139  }
 140