b43legacy: fix a lower bounds test

[ Upstream commit c1c8380b0320ab757e60ed90efc8b1992a943256 ]

The problem is that "channel" is an unsigned int, when it's less 5 the
value of "channel - 5" is not a negative number as one would expect but
is very high positive value instead.

This means that "start" becomes a very high positive value.  The result
of that is that we never enter the "for (i = start; i <= end; i++) {"
loop.  Instead of storing the result from b43legacy_radio_aci_detect()
it just uses zero.

Fixes: 75388acd0cd8 ("[B43LEGACY]: add mac80211-based driver for legacy BCM43xx devices")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Michael Büsch <m@bues.ch>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211006073542.GD8404@kili
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/b43legacy/radio.c b/drivers/net/wireless/b43legacy/radio.c
index 9501420340a91f58cf70cd6fe32c72bdec5b2b61..5b1e8890305c1d8464f6f4cd4616d4bb35363632 100644 (file)
--- a/drivers/net/wireless/b43legacy/radio.c
+++ b/drivers/net/wireless/b43legacy/radio.c
@@ -299,7 +299,7 @@ u8 b43legacy_radio_aci_scan(struct b43legacy_wldev *dev)
                            & 0x7FFF);
        b43legacy_set_all_gains(dev, 3, 8, 1);
 
-       start = (channel - 5 > 0) ? channel - 5 : 1;
+       start = (channel > 5) ? channel - 5 : 1;
        end = (channel + 5 < 14) ? channel + 5 : 13;
 
        for (i = start; i <= end; i++) {