target/linux/generic/backport-4.19/334-v4.15-netfilter-nf_tables-fix-potential-NULL-ptr-deref-in-.patch

   1 From: Hangbin Liu <liuhangbin@gmail.com>
   2 Date: Mon, 25 Dec 2017 11:34:54 +0800
   3 Subject: [PATCH] netfilter: nf_tables: fix potential NULL-ptr deref in
   4  nf_tables_dump_obj_done()
   5
   6 If there is no NFTA_OBJ_TABLE and NFTA_OBJ_TYPE, the c.data will be NULL in
   7 nf_tables_getobj(). So before free filter->table in nf_tables_dump_obj_done(),
   8 we need to check if filter is NULL first.
   9
  10 Fixes: e46abbcc05aa ("netfilter: nf_tables: Allow table names of up to 255 chars")
  11 Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
  12 Acked-by: Phil Sutter <phil@nwl.cc>
  13 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
  14 ---
  15
  16 --- a/net/netfilter/nf_tables_api.c
  17 +++ b/net/netfilter/nf_tables_api.c
  18 @@ -5330,8 +5330,10 @@ static int nf_tables_dump_flowtable_done
  19         if (!filter)
  20                 return 0;
  21
  22 -       kfree(filter->table);
  23 -       kfree(filter);
  24 +       if (filter) {
  25 +               kfree(filter->table);
  26 +               kfree(filter);
  27 +       }
  28
  29         return 0;
  30  }