wifi: cfg80211: reject non-conformant 6 GHz center frequencies

On 6 GHz (and also 5 GHz to some degree), only a specific set of center
frequencies should be used depending on the channel bandwidth. Verify
this is the case on 6 GHz. For 5 GHz, we are more accepting as there are
APs that got it wrong historically.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240602102200.876b10a2beda.I0d3d0daea4014e99654437ff6691378dbe452652@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index bf2fdcd420191b0149752feae13f8676c57924ee..e579d7e1425fe91b8060586b5e4d54cacc4e209f 100644 (file)
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -263,6 +263,37 @@ static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
        return nl80211_chan_width_to_mhz(c->width);
 }
 
+static bool cfg80211_valid_center_freq(u32 center,
+                                      enum nl80211_chan_width width)
+{
+       int bw;
+       int step;
+
+       /* We only do strict verification on 6 GHz */
+       if (center < 5955 || center > 7115)
+               return true;
+
+       bw = nl80211_chan_width_to_mhz(width);
+       if (bw < 0)
+               return false;
+
+       /* Validate that the channels bw is entirely within the 6 GHz band */
+       if (center - bw / 2 < 5945 || center + bw / 2 > 7125)
+               return false;
+
+       /* With 320 MHz the permitted channels overlap */
+       if (bw == 320)
+               step = 160;
+       else
+               step = bw;
+
+       /*
+        * Valid channels are packed from lowest frequency towards higher ones.
+        * So test that the lower frequency alignes with one of these steps.
+        */
+       return (center - bw / 2 - 5945) % step == 0;
+}
+
 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
 {
        u32 control_freq, oper_freq;
@@ -374,6 +405,13 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
                return false;
        }
 
+       if (!cfg80211_valid_center_freq(chandef->center_freq1, chandef->width))
+               return false;
+
+       if (chandef->width == NL80211_CHAN_WIDTH_80P80 &&
+           !cfg80211_valid_center_freq(chandef->center_freq2, chandef->width))
+               return false;
+
        /* channel 14 is only for IEEE 802.11b */
        if (chandef->center_freq1 == 2484 &&
            chandef->width != NL80211_CHAN_WIDTH_20_NOHT)

diff --git a/net/wireless/tests/chan.c b/net/wireless/tests/chan.c
index d02258ac2dabd23dc87ec379a6cb58c74e8a35de..74bbee25085f8d98690c5aed52810d56c10b0d3c 100644 (file)
--- a/net/wireless/tests/chan.c
+++ b/net/wireless/tests/chan.c
@@ -113,16 +113,16 @@ static const struct chandef_compat_case {
                },
        },
        {
-               .desc = "different primary 160 MHz",
+               .desc = "different primary 320 MHz",
                .c1 = {
                        .width = NL80211_CHAN_WIDTH_320,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 + 150,
+                       .center_freq1 = 6475 + 110,
                },
                .c2 = {
                        .width = NL80211_CHAN_WIDTH_320,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 - 10,
+                       .center_freq1 = 6475 - 50,
                },
        },
        {
@@ -131,12 +131,12 @@ static const struct chandef_compat_case {
                .c1 = {
                        .width = NL80211_CHAN_WIDTH_160,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 + 70,
+                       .center_freq1 = 6475 + 30,
                },
                .c2 = {
                        .width = NL80211_CHAN_WIDTH_320,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 - 10,
+                       .center_freq1 = 6475 - 50,
                },
                .compat = true,
        },
@@ -145,12 +145,12 @@ static const struct chandef_compat_case {
                .c1 = {
                        .width = NL80211_CHAN_WIDTH_160,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 + 70,
+                       .center_freq1 = 6475 + 30,
                },
                .c2 = {
                        .width = NL80211_CHAN_WIDTH_320,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 - 10,
+                       .center_freq1 = 6475 - 50,
                        .punctured = 0xf,
                },
                .compat = true,
@@ -160,13 +160,13 @@ static const struct chandef_compat_case {
                .c1 = {
                        .width = NL80211_CHAN_WIDTH_160,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 + 70,
+                       .center_freq1 = 6475 + 30,
                        .punctured = 0xc0,
                },
                .c2 = {
                        .width = NL80211_CHAN_WIDTH_320,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 - 10,
+                       .center_freq1 = 6475 - 50,
                        .punctured = 0xc000,
                },
                .compat = true,
@@ -176,13 +176,13 @@ static const struct chandef_compat_case {
                .c1 = {
                        .width = NL80211_CHAN_WIDTH_160,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 + 70,
+                       .center_freq1 = 6475 + 30,
                        .punctured = 0x80,
                },
                .c2 = {
                        .width = NL80211_CHAN_WIDTH_320,
                        .chan = &chan_6ghz_105,
-                       .center_freq1 = 6475 - 10,
+                       .center_freq1 = 6475 - 50,
                        .punctured = 0xc000,
                },
        },