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Date:   Thu, 21 Sep 2023 09:58:11 +0000
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Message-ID: <20230921-strncpy-drivers-input-rmi4-rmi_f34-c-v1-1-4aef2e84b8d2@google.com>
Subject: [PATCH] Input: synaptics-rmi4 - replace deprecated strncpy
From:   Justin Stitt <justinstitt@google.com>
To:     Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc:     linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org,
        Justin Stitt <justinstitt@google.com>
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`strncpy` is deprecated for use on NUL-terminated destination strings [1]

Let's use memcpy() as the bounds have already been checked and this
decays into a simple byte copy from one buffer to another removing any
ambiguity that strncpy has.

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.

Similar to Kees' suggestion here [2]

[2]: https://lore.kernel.org/all/202309142045.7CBAE940E@keescook/
---
 drivers/input/rmi4/rmi_f34.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/rmi4/rmi_f34.c b/drivers/input/rmi4/rmi_f34.c
index 0d9a5756e3f5..3b3ac71e53dc 100644
--- a/drivers/input/rmi4/rmi_f34.c
+++ b/drivers/input/rmi4/rmi_f34.c
@@ -471,7 +471,7 @@ static ssize_t rmi_driver_update_fw_store(struct device *dev,
 	if (buf[count - 1] == '\0' || buf[count - 1] == '\n')
 		copy_count -= 1;
 
-	strncpy(fw_name, buf, copy_count);
+	memcpy(fw_name, buf, copy_count);
 	fw_name[copy_count] = '\0';
 
 	ret = request_firmware(&fw, fw_name, dev);

---
base-commit: 2cf0f715623872823a72e451243bbf555d10d032
change-id: 20230921-strncpy-drivers-input-rmi4-rmi_f34-c-4a6945316cea

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