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From:   Baochen Qiang <quic_bqiang@quicinc.com>
To:     <ath11k@lists.infradead.org>
CC:     <linux-wireless@vger.kernel.org>
Subject: [PATCH] ath11k: Fix warning on variable 'sar' dereference before check
Date:   Tue, 17 May 2022 08:48:44 +0800
Message-ID: <20220517004844.2412660-1-quic_bqiang@quicinc.com>
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We are seeing below warning:
warn: variable dereferenced before check 'sar'

Fix it by moving ahead pointer check on 'sar'.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3

Fixes: 652f69ed9c1b ("ath11k: Add support for SAR")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
---
 drivers/net/wireless/ath/ath11k/mac.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index ee1590b16eff..7d574ad67e59 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -8297,11 +8297,15 @@ static int ath11k_mac_op_set_bios_sar_specs(struct ieee80211_hw *hw,
 					    const struct cfg80211_sar_specs *sar)
 {
 	struct ath11k *ar = hw->priv;
-	const struct cfg80211_sar_sub_specs *sspec = sar->sub_specs;
+	const struct cfg80211_sar_sub_specs *sspec;
 	int ret, index;
 	u8 *sar_tbl;
 	u32 i;
 
+	if (!sar || sar->type != NL80211_SAR_TYPE_POWER ||
+	    sar->num_sub_specs == 0)
+		return -EINVAL;
+
 	mutex_lock(&ar->conf_mutex);
 
 	if (!test_bit(WMI_TLV_SERVICE_BIOS_SAR_SUPPORT, ar->ab->wmi_ab.svc_map) ||
@@ -8310,12 +8314,6 @@ static int ath11k_mac_op_set_bios_sar_specs(struct ieee80211_hw *hw,
 		goto exit;
 	}
 
-	if (!sar || sar->type != NL80211_SAR_TYPE_POWER ||
-	    sar->num_sub_specs == 0) {
-		ret = -EINVAL;
-		goto exit;
-	}
-
 	ret = ath11k_wmi_pdev_set_bios_geo_table_param(ar);
 	if (ret) {
 		ath11k_warn(ar->ab, "failed to set geo table: %d\n", ret);
@@ -8328,6 +8326,7 @@ static int ath11k_mac_op_set_bios_sar_specs(struct ieee80211_hw *hw,
 		goto exit;
 	}
 
+	sspec = sar->sub_specs;
 	for (i = 0; i < sar->num_sub_specs; i++) {
 		if (sspec->freq_range_index >= (BIOS_SAR_TABLE_LEN >> 1)) {
 			ath11k_warn(ar->ab, "Ignore bad frequency index %u, max allowed %u\n",

base-commit: 14c24bc11b43da59fe41d79d3c1b29decc3d21f3
-- 
2.25.1