target/linux/generic/backport-5.15/733-v6.2-01-net-ethernet-mtk_eth_soc-Avoid-truncating-allocation.patch

   1 From f3eceaed9edd7c0e0d9fb057613131f92973626f Mon Sep 17 00:00:00 2001
   2 From: Kees Cook <keescook@chromium.org>
   3 Date: Fri, 27 Jan 2023 14:38:54 -0800
   4 Subject: [PATCH] net: ethernet: mtk_eth_soc: Avoid truncating allocation
   5
   6 There doesn't appear to be a reason to truncate the allocation used for
   7 flow_info, so do a full allocation and remove the unused empty struct.
   8 GCC does not like having a reference to an object that has been
   9 partially allocated, as bounds checking may become impossible when
  10 such an object is passed to other code. Seen with GCC 13:
  11
  12 ../drivers/net/ethernet/mediatek/mtk_ppe.c: In function 'mtk_foe_entry_commit_subflow':
  13 ../drivers/net/ethernet/mediatek/mtk_ppe.c:623:18: warning: array subscript 'struct mtk_flow_entry[0]' is partly outside array bounds of 'unsigned char[48]' [-Warray-bounds=]
  14   623 |         flow_info->l2_data.base_flow = entry;
  15       |                  ^~
  16
  17 Cc: Felix Fietkau <nbd@nbd.name>
  18 Cc: John Crispin <john@phrozen.org>
  19 Cc: Sean Wang <sean.wang@mediatek.com>
  20 Cc: Mark Lee <Mark-MC.Lee@mediatek.com>
  21 Cc: Lorenzo Bianconi <lorenzo@kernel.org>
  22 Cc: "David S. Miller" <davem@davemloft.net>
  23 Cc: Eric Dumazet <edumazet@google.com>
  24 Cc: Jakub Kicinski <kuba@kernel.org>
  25 Cc: Paolo Abeni <pabeni@redhat.com>
  26 Cc: Matthias Brugger <matthias.bgg@gmail.com>
  27 Cc: netdev@vger.kernel.org
  28 Cc: linux-arm-kernel@lists.infradead.org
  29 Cc: linux-mediatek@lists.infradead.org
  30 Signed-off-by: Kees Cook <keescook@chromium.org>
  31 Reviewed-by: Simon Horman <simon.horman@corigine.com>
  32 Link: https://lore.kernel.org/r/20230127223853.never.014-kees@kernel.org
  33 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
  34 ---
  35  drivers/net/ethernet/mediatek/mtk_ppe.c | 3 +--
  36  drivers/net/ethernet/mediatek/mtk_ppe.h | 1 -
  37  2 files changed, 1 insertion(+), 3 deletions(-)
  38
  39 --- a/drivers/net/ethernet/mediatek/mtk_ppe.c
  40 +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
  41 @@ -621,8 +621,7 @@ mtk_foe_entry_commit_subflow(struct mtk_
  42         u32 ib1_mask = mtk_get_ib1_pkt_type_mask(ppe->eth) | MTK_FOE_IB1_UDP;
  43         int type;
  44
  45 -       flow_info = kzalloc(offsetof(struct mtk_flow_entry, l2_data.end),
  46 -                           GFP_ATOMIC);
  47 +       flow_info = kzalloc(sizeof(*flow_info), GFP_ATOMIC);
  48         if (!flow_info)
  49                 return;
  50
  51 --- a/drivers/net/ethernet/mediatek/mtk_ppe.h
  52 +++ b/drivers/net/ethernet/mediatek/mtk_ppe.h
  53 @@ -279,7 +279,6 @@ struct mtk_flow_entry {
  54                 struct {
  55                         struct mtk_flow_entry *base_flow;
  56                         struct hlist_node list;
  57 -                       struct {} end;
  58                 } l2_data;
  59         };
  60         struct rhash_head node;