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Date:   Tue, 22 Feb 2022 20:38:41 -0600
From:   "Gustavo A. R. Silva" <gustavoars@kernel.org>
To:     linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Kalle Valo <kvalo@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, netdev@vger.kernel.org,
        linux-hardening@vger.kernel.org,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>
Subject: [PATCH 2/6][next] ath6kl: wmi: Replace one-element array with
 flexible-array member in struct wmi_start_scan_cmd
Message-ID: <c7fcd70b571aecc08393a1a5ad96c0f5f35eeb15.1645583264.git.gustavoars@kernel.org>
References: <cover.1645583264.git.gustavoars@kernel.org>
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Precedence: bulk

Replace one-element array with flexible-array member in struct
wmi_start_scan_cmd. Also, make use of the struct_size() helper.

This issue was found with the help of Coccinelle and audited and fixed,
manually.

Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/wireless/ath/ath6kl/wmi.c | 8 +-------
 drivers/net/wireless/ath/ath6kl/wmi.h | 2 +-
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index e1c950014f3e..bdfc057c5a82 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -1959,21 +1959,15 @@ static int ath6kl_wmi_startscan_cmd(struct wmi *wmi, u8 if_idx,
 {
 	struct sk_buff *skb;
 	struct wmi_start_scan_cmd *sc;
-	s8 size;
 	int i, ret;
 
-	size = sizeof(struct wmi_start_scan_cmd);
-
 	if ((scan_type != WMI_LONG_SCAN) && (scan_type != WMI_SHORT_SCAN))
 		return -EINVAL;
 
 	if (num_chan > WMI_MAX_CHANNELS)
 		return -EINVAL;
 
-	if (num_chan)
-		size += sizeof(u16) * (num_chan - 1);
-
-	skb = ath6kl_wmi_get_new_buf(size);
+	skb = ath6kl_wmi_get_new_buf(struct_size(sc, ch_list, num_chan));
 	if (!skb)
 		return -ENOMEM;
 
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h
index 322539ed9c12..9e168752bec2 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.h
+++ b/drivers/net/wireless/ath/ath6kl/wmi.h
@@ -889,7 +889,7 @@ struct wmi_start_scan_cmd {
 	u8 num_ch;
 
 	/* channels in Mhz */
-	__le16 ch_list[1];
+	__le16 ch_list[];
 } __packed;
 
 /*
-- 
2.27.0