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From: Kalle Valo <kvalo@kernel.org>
To: linux-wireless@vger.kernel.org
Cc: chunkeey@googlemail.com
Subject: [PATCH] wifi: p54: fix GCC format truncation warning with wiphy->fw_version
Date: Tue, 19 Dec 2023 18:25:16 +0200
Message-Id: <20231219162516.898205-1-kvalo@kernel.org>
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GCC 13.2 warns:

drivers/net/wireless/intersil/p54/fwio.c:128:34: warning: '%s' directive output may be truncated writing up to 39 bytes into a region of size 32 [-Wformat-truncation=]
drivers/net/wireless/intersil/p54/fwio.c:128:33: note: directive argument in the range [0, 16777215]
drivers/net/wireless/intersil/p54/fwio.c:128:33: note: directive argument in the range [0, 255]
drivers/net/wireless/intersil/p54/fwio.c:127:17: note: 'snprintf' output between 7 and 52 bytes into a destination of size 32

The issue here is that wiphy->fw_version is 32 bytes and in theory the string
we try to place there can be 39 bytes. wiphy->fw_version is used for providing
the firmware version to user space via ethtool, so not really important.
fw_version in theory can be 24 bytes but in practise it's shorter, so even if
print only 19 bytes via ethtool there should not be any practical difference.

I did consider removing fw_var from the string altogether or making the maximum
length for fw_version 19 bytes, but chose this approach as it was the least
intrusive.

Signed-off-by: Kalle Valo <kvalo@kernel.org>
---
 drivers/net/wireless/intersil/p54/fwio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intersil/p54/fwio.c b/drivers/net/wireless/intersil/p54/fwio.c
index b52cce38115d..c4fe70e05b9b 100644
--- a/drivers/net/wireless/intersil/p54/fwio.c
+++ b/drivers/net/wireless/intersil/p54/fwio.c
@@ -125,7 +125,7 @@ int p54_parse_firmware(struct ieee80211_hw *dev, const struct firmware *fw)
 			   "FW rev %s - Softmac protocol %x.%x\n",
 			   fw_version, priv->fw_var >> 8, priv->fw_var & 0xff);
 		snprintf(dev->wiphy->fw_version, sizeof(dev->wiphy->fw_version),
-				"%s - %x.%x", fw_version,
+				"%.19s - %x.%x", fw_version,
 				priv->fw_var >> 8, priv->fw_var & 0xff);
 	}
 

base-commit: 4e87ca403e2008b9e182239e1abbf6876a55eb33
-- 
2.39.2