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Date:   Fri, 13 Oct 2023 21:19:02 +0000
Mime-Version: 1.0
Message-ID: <20231013-strncpy-drivers-net-wireless-ath-ath6kl-init-c-v1-1-d69c599b49a9@google.com>
Subject: [PATCH] ath6kl: replace deprecated strncpy with memcpy
From:   Justin Stitt <justinstitt@google.com>
To:     Kalle Valo <kvalo@kernel.org>
Cc:     linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org,
        Justin Stitt <justinstitt@google.com>
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Precedence: bulk

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous
interfaces.

The affected code's purpose is to truncate strings that are too long
with "..." like:
foobar -> fo...

The lengths have been carefully calculated and as such this has decayed
to a simple byte copy from one buffer to another -- let's use memcpy().

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.

Found with: $ rg "strncpy\("
---
 drivers/net/wireless/ath/ath6kl/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath6kl/init.c b/drivers/net/wireless/ath/ath6kl/init.c
index 201e45554070..15f455adb860 100644
--- a/drivers/net/wireless/ath/ath6kl/init.c
+++ b/drivers/net/wireless/ath/ath6kl/init.c
@@ -1677,7 +1677,7 @@ static void ath6kl_init_get_fwcaps(struct ath6kl *ar, char *buf, size_t buf_len)
 
 			/* add "..." to the end of string */
 			trunc_len = strlen(trunc) + 1;
-			strncpy(buf + buf_len - trunc_len, trunc, trunc_len);
+			memcpy(buf + buf_len - trunc_len, trunc, trunc_len);
 
 			return;
 		}

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231013-strncpy-drivers-net-wireless-ath-ath6kl-init-c-ffdb45d76eaf

Best regards,
--
Justin Stitt <justinstitt@google.com>