nl80211: correct checks for NL80211_MESHCONF_HT_OPMODE value

Previously, NL80211_MESHCONF_HT_OPMODE validation rejected correct
flag combinations, e.g. IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED |
IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT.

Doing just a range-check allows setting flags that don't exist (0x8)
and invalid flag combinations.

Implements some checks based on IEEE 802.11 2012 8.4.2.59 "HT
Operation element".

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
[reword commit message, simplify a bit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 46417f9cce6810675f8d79f153260e61a689a140..f02653a08993334f98517d30c9c319f780ce9342 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5380,6 +5380,7 @@ static int nl80211_parse_mesh_config(struct genl_info *info,
 {
        struct nlattr *tb[NL80211_MESHCONF_ATTR_MAX + 1];
        u32 mask = 0;
+       u16 ht_opmode;
 
 #define FILL_IN_MESH_PARAM_IF_SET(tb, cfg, param, min, max, mask, attr, fn) \
 do {                                                                       \
@@ -5471,9 +5472,36 @@ do {                                                                         \
        FILL_IN_MESH_PARAM_IF_SET(tb, cfg, rssi_threshold, -255, 0,
                                  mask, NL80211_MESHCONF_RSSI_THRESHOLD,
                                  nl80211_check_s32);
-       FILL_IN_MESH_PARAM_IF_SET(tb, cfg, ht_opmode, 0, 16,
-                                 mask, NL80211_MESHCONF_HT_OPMODE,
-                                 nl80211_check_u16);
+       /*
+        * Check HT operation mode based on
+        * IEEE 802.11 2012 8.4.2.59 HT Operation element.
+        */
+       if (tb[NL80211_MESHCONF_HT_OPMODE]) {
+               ht_opmode = nla_get_u16(tb[NL80211_MESHCONF_HT_OPMODE]);
+
+               if (ht_opmode & ~(IEEE80211_HT_OP_MODE_PROTECTION |
+                                 IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT |
+                                 IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT))
+                       return -EINVAL;
+
+               if ((ht_opmode & IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT) &&
+                   (ht_opmode & IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT))
+                       return -EINVAL;
+
+               switch (ht_opmode & IEEE80211_HT_OP_MODE_PROTECTION) {
+               case IEEE80211_HT_OP_MODE_PROTECTION_NONE:
+               case IEEE80211_HT_OP_MODE_PROTECTION_20MHZ:
+                       if (ht_opmode & IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT)
+                               return -EINVAL;
+                       break;
+               case IEEE80211_HT_OP_MODE_PROTECTION_NONMEMBER:
+               case IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED:
+                       if (!(ht_opmode & IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT))
+                               return -EINVAL;
+                       break;
+               }
+               cfg->ht_opmode = ht_opmode;
+       }
        FILL_IN_MESH_PARAM_IF_SET(tb, cfg, dot11MeshHWMPactivePathToRootTimeout,
                                  1, 65535, mask,
                                  NL80211_MESHCONF_HWMP_PATH_TO_ROOT_TIMEOUT,