Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) client-ip=2620:137:e000::3:4;
Date:   Wed, 13 Sep 2023 00:51:05 +0000
Mime-Version: 1.0
Message-ID: <20230913-strncpy-drivers-crypto-intel-qat-qat_common-qat_uclo-c-v1-1-88a6c07fc924@google.com>
Subject: [PATCH] crypto: qat - refactor deprecated strncpy
From:   Justin Stitt <justinstitt@google.com>
To:     Giovanni Cabiddu <giovanni.cabiddu@intel.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>
Cc:     qat-linux@intel.com, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org,
        Justin Stitt <justinstitt@google.com>
Content-Type: text/plain; charset="utf-8"
Precedence: bulk

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

We should prefer more robust and less ambiguous string interfaces.

`buf` is expected to be NUL-terminated for its eventual use in
`kstrtoul()` and NUL-padding is not required.

Due to the above, a suitable replacement is `strscpy` [2] due to the
fact that it guarantees NUL-termination on the destination buffer.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
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.
---
 drivers/crypto/intel/qat/qat_common/qat_uclo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/intel/qat/qat_common/qat_uclo.c b/drivers/crypto/intel/qat/qat_common/qat_uclo.c
index ce837bcc1cab..e2f82128043e 100644
--- a/drivers/crypto/intel/qat/qat_common/qat_uclo.c
+++ b/drivers/crypto/intel/qat/qat_common/qat_uclo.c
@@ -200,7 +200,7 @@ static int qat_uclo_parse_num(char *str, unsigned int *num)
 	unsigned long ae = 0;
 	int i;
 
-	strncpy(buf, str, 15);
+	strscpy(buf, str, sizeof(buf));
 	for (i = 0; i < 16; i++) {
 		if (!isdigit(buf[i])) {
 			buf[i] = '\0';

---
base-commit: 2dde18cd1d8fac735875f2e4987f11817cc0bc2c
change-id: 20230913-strncpy-drivers-crypto-intel-qat-qat_common-qat_uclo-c-0f4b16830f59

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