releases/4.4.160/cfg80211-fix-a-type-issue-in-ieee80211_chandef_to_operating_class.patch

   1 From foo@baz Thu Oct  4 12:39:38 PDT 2018
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Fri, 31 Aug 2018 11:10:55 +0300
   4 Subject: cfg80211: fix a type issue in ieee80211_chandef_to_operating_class()
   5
   6 From: Dan Carpenter <dan.carpenter@oracle.com>
   7
   8 [ Upstream commit 8442938c3a2177ba16043b3a935f2c78266ad399 ]
   9
  10 The "chandef->center_freq1" variable is a u32 but "freq" is a u16 so we
  11 are truncating away the high bits.  I noticed this bug because in commit
  12 9cf0a0b4b64a ("cfg80211: Add support for 60GHz band channels 5 and 6")
  13 we made "freq <= 56160 + 2160 * 6" a valid requency when before it was
  14 only "freq <= 56160 + 2160 * 4" that was valid.  It introduces a static
  15 checker warning:
  16
  17     net/wireless/util.c:1571 ieee80211_chandef_to_operating_class()
  18     warn: always true condition '(freq <= 56160 + 2160 * 6) => (0-u16max <= 69120)'
  19
  20 But really we probably shouldn't have been truncating the high bits
  21 away to begin with.
  22
  23 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  24 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  25 Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27 ---
  28  net/wireless/util.c |    2 +-
  29  1 file changed, 1 insertion(+), 1 deletion(-)
  30
  31 --- a/net/wireless/util.c
  32 +++ b/net/wireless/util.c
  33 @@ -1360,7 +1360,7 @@ bool ieee80211_chandef_to_operating_clas
  34                                           u8 *op_class)
  35  {
  36         u8 vht_opclass;
  37 -       u16 freq = chandef->center_freq1;
  38 +       u32 freq = chandef->center_freq1;
  39
  40         if (freq >= 2412 && freq <= 2472) {
  41                 if (chandef->width > NL80211_CHAN_WIDTH_40)