git.openwrt.org Git - openwrt/staging/ansuel.git/blob

   1 From 2ae5c9248e06dac2c2360be26b4e25f673238337 Mon Sep 17 00:00:00 2001
   2 From: Jeff Johnson <quic_jjohnson@quicinc.com>
   3 Date: Thu, 31 Aug 2023 11:22:58 -0700
   4 Subject: [PATCH] wifi: mac80211: Use flexible array in struct ieee80211_tim_ie
   5
   6 Currently struct ieee80211_tim_ie defines:
   7         u8 virtual_map[1];
   8
   9 Per the guidance in [1] change this to be a flexible array.
  10
  11 Per the discussion in [2] wrap the virtual_map in a union with a u8
  12 item in order to preserve the existing expectation that the
  13 virtual_map must contain at least one octet (at least when used in a
  14 non-S1G PPDU). This means that no driver changes are required.
  15
  16 [1] https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays
  17 [2] https://lore.kernel.org/linux-wireless/202308301529.AC90A9EF98@keescook/
  18
  19 Suggested-by: Kees Cook <keescook@chromium.org>
  20 Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
  21 Reviewed-by: Kees Cook <keescook@chromium.org>
  22 Link: https://lore.kernel.org/r/20230831-ieee80211_tim_ie-v3-2-e10ff584ab5d@quicinc.com
  23 [add wifi prefix]
  24 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  25 ---
  26  include/linux/ieee80211.h | 13 ++++++++++---
  27  1 file changed, 10 insertions(+), 3 deletions(-)
  28
  29 --- a/include/linux/ieee80211.h
  30 +++ b/include/linux/ieee80211.h
  31 @@ -951,17 +951,24 @@ struct ieee80211_wide_bw_chansw_ie {
  32   * @dtim_count: DTIM Count
  33   * @dtim_period: DTIM Period
  34   * @bitmap_ctrl: Bitmap Control
  35 + * @required_octet: "Syntatic sugar" to force the struct size to the
  36 + *                  minimum valid size when carried in a non-S1G PPDU
  37   * @virtual_map: Partial Virtual Bitmap
  38   *
  39   * This structure represents the payload of the "TIM element" as
  40 - * described in IEEE Std 802.11-2020 section 9.4.2.5.
  41 + * described in IEEE Std 802.11-2020 section 9.4.2.5. Note that this
  42 + * definition is only applicable when the element is carried in a
  43 + * non-S1G PPDU. When the TIM is carried in an S1G PPDU, the Bitmap
  44 + * Control and Partial Virtual Bitmap may not be present.
  45   */
  46  struct ieee80211_tim_ie {
  47         u8 dtim_count;
  48         u8 dtim_period;
  49         u8 bitmap_ctrl;
  50 -       /* variable size: 1 - 251 bytes */
  51 -       u8 virtual_map[1];
  52 +       union {
  53 +               u8 required_octet;
  54 +               DECLARE_FLEX_ARRAY(u8, virtual_map);
  55 +       };
  56  } __packed;
  57
  58  /**