releases/3.18.85/netfilter-nf_tables-fix-oob-access.patch

   1 From foo@baz Tue Nov 28 10:58:31 CET 2017
   2 From: Florian Westphal <fw@strlen.de>
   3 Date: Tue, 13 Dec 2016 13:59:33 +0100
   4 Subject: netfilter: nf_tables: fix oob access
   5
   6 From: Florian Westphal <fw@strlen.de>
   7
   8
   9 [ Upstream commit 3e38df136e453aa69eb4472108ebce2fb00b1ba6 ]
  10
  11 BUG: KASAN: slab-out-of-bounds in nf_tables_rule_destroy+0xf1/0x130 at addr ffff88006a4c35c8
  12 Read of size 8 by task nft/1607
  13
  14 When we've destroyed last valid expr, nft_expr_next() returns an invalid expr.
  15 We must not dereference it unless it passes != nft_expr_last() check.
  16
  17 Signed-off-by: Florian Westphal <fw@strlen.de>
  18 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
  19 Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21 ---
  22  net/netfilter/nf_tables_api.c |    2 +-
  23  1 file changed, 1 insertion(+), 1 deletion(-)
  24
  25 --- a/net/netfilter/nf_tables_api.c
  26 +++ b/net/netfilter/nf_tables_api.c
  27 @@ -1869,7 +1869,7 @@ static void nf_tables_rule_destroy(const
  28          * is called on error from nf_tables_newrule().
  29          */
  30         expr = nft_expr_first(rule);
  31 -       while (expr->ops && expr != nft_expr_last(rule)) {
  32 +       while (expr != nft_expr_last(rule) && expr->ops) {
  33                 nf_tables_expr_destroy(ctx, expr);
  34                 expr = nft_expr_next(expr);
  35         }