[PATCH][next] ath11k: avoid null pointer dereference when pointer band is null

From: Colin King
Date: Sat Jan 11 2020 - 04:08:38 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

In the unlikely event that cap->supported_bands has neither
WMI_HOST_WLAN_2G_CAP set or WMI_HOST_WLAN_5G_CAP set then pointer
band is null and a null dereference occurs when assigning
band->n_iftype_data. Move the assignment to the if blocks to
avoid this. Cleans up static analysis warnings.

Addresses-Coverity: ("Explicit null dereference")
Fixes: 9f056ed8ee01 ("ath11k: add HE support")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath11k/mac.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 556eef9881a7..4a364cfe37ed 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -3520,8 +3520,8 @@ static int ath11k_mac_copy_he_cap(struct ath11k *ar,
static void ath11k_mac_setup_he_cap(struct ath11k *ar,
struct ath11k_pdev_cap *cap)
{
- struct ieee80211_supported_band *band = NULL;
- int count = 0;
+ struct ieee80211_supported_band *band;
+ int count;

if (cap->supported_bands & WMI_HOST_WLAN_2G_CAP) {
count = ath11k_mac_copy_he_cap(ar, cap,
@@ -3529,6 +3529,7 @@ static void ath11k_mac_setup_he_cap(struct ath11k *ar,
NL80211_BAND_2GHZ);
band = &ar->mac.sbands[NL80211_BAND_2GHZ];
band->iftype_data = ar->mac.iftype[NL80211_BAND_2GHZ];
+ band->n_iftype_data = count;
}

if (cap->supported_bands & WMI_HOST_WLAN_5G_CAP) {
@@ -3537,9 +3538,8 @@ static void ath11k_mac_setup_he_cap(struct ath11k *ar,
NL80211_BAND_5GHZ);
band = &ar->mac.sbands[NL80211_BAND_5GHZ];
band->iftype_data = ar->mac.iftype[NL80211_BAND_5GHZ];
+ band->n_iftype_data = count;
}
-
- band->n_iftype_data = count;
}

static int __ath11k_set_antenna(struct ath11k *ar, u32 tx_ant, u32 rx_ant)
--
2.24.0