ath9k: add compile time checking for the size of the channel list

This prevents random memory corruption if the number of channels ever gets
changed without an update to the internal channel array size.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 7f696c82ca0a55d0f40c2d3c26aba72afb710c57..6b9233472fbf12c8afe9eaae5411d35d9eb957b3 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -61,6 +61,8 @@
 
 #define ATH9K_RSSI_BAD                 -128
 
+#define ATH9K_NUM_CHANNELS     38
+
 /* Register read/write primitives */
 #define REG_WRITE(_ah, _reg, _val) \
        ath9k_hw_common(_ah)->ops->write((_ah), (_val), (_reg))
@@ -618,7 +620,7 @@ struct ath_hw {
        struct ath9k_hw_version hw_version;
        struct ath9k_ops_config config;
        struct ath9k_hw_capabilities caps;
-       struct ath9k_channel channels[38];
+       struct ath9k_channel channels[ATH9K_NUM_CHANNELS];
        struct ath9k_channel *curchan;
 
        union {

diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index d76003c06fe4dc1a53be4b82a9010213a1bcf7ad..a4c5ed41b176c09f17706eba9d1a4696d7dd3966 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -481,6 +481,10 @@ static int ath9k_init_channels_rates(struct ath_softc *sc)
 {
        void *channels;
 
+       BUILD_BUG_ON(ARRAY_SIZE(ath9k_2ghz_chantable) +
+                    ARRAY_SIZE(ath9k_5ghz_chantable) !=
+                    ATH9K_NUM_CHANNELS);
+
        if (test_bit(ATH9K_MODE_11G, sc->sc_ah->caps.wireless_modes)) {
                channels = kmemdup(ath9k_2ghz_chantable,
                        sizeof(ath9k_2ghz_chantable), GFP_KERNEL);