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From:   Haowen Bai <baihaowen@meizu.com>
To:     Kalle Valo <kvalo@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        "Paolo Abeni" <pabeni@redhat.com>
CC:     Haowen Bai <baihaowen@meizu.com>, <ath11k@lists.infradead.org>,
        <linux-wireless@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH] ath11k: Fix pointer dereferenced before checking
Date:   Mon, 16 May 2022 11:23:56 +0800
Message-ID: <1652671437-20235-1-git-send-email-baihaowen@meizu.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The pointer sspec is dereferencing pointer sar before sar is being
null checked. Fix this by assigning sar->sub_specs to sspec only if
sar is not NULL, otherwise just NULL. The code has checked sar whether
it is NULL or not as below, but use before checking.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
---
 drivers/net/wireless/ath/ath11k/mac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 1957e1713548..fe97c9a3c1c5 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -8287,7 +8287,7 @@ 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 = sar ? sar->sub_specs : NULL;
 	int ret, index;
 	u8 *sar_tbl;
 	u32 i;
-- 
2.7.4