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Date:   Thu, 05 Oct 2023 21:05:42 +0000
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Message-ID: <20231005-strncpy-drivers-net-ethernet-brocade-bna-bfa_ioc-c-v1-1-8dfd30123afc@google.com>
Subject: [PATCH] bna: replace deprecated strncpy with strscpy
From:   Justin Stitt <justinstitt@google.com>
To:     Rasesh Mody <rmody@marvell.com>,
        Sudarsana Kalluru <skalluru@marvell.com>,
        GR-Linux-NIC-Dev@marvell.com,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     netdev@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] and as such we should prefer more robust and less ambiguous string
interfaces.

bfa_ioc_get_adapter_manufacturer() simply copies a string literal into
`manufacturer`.

NUL-padding is not needed because bfa_ioc_get_adapter_manufacturer()'s
only caller passes `ad_attr` (which is from ioc_attr) which is then
memset to 0.
 bfa_nw_ioc_get_attr() ->
   bfa_ioc_get_adapter_attr() ->
     bfa_nw_ioc_get_attr() ->
       memset((void *)ioc_attr, 0, sizeof(struct bfa_ioc_attr));

Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.

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/net/ethernet/brocade/bna/bfa_ioc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/brocade/bna/bfa_ioc.c b/drivers/net/ethernet/brocade/bna/bfa_ioc.c
index b07522ac3e74..497cb65f2d06 100644
--- a/drivers/net/ethernet/brocade/bna/bfa_ioc.c
+++ b/drivers/net/ethernet/brocade/bna/bfa_ioc.c
@@ -2839,7 +2839,7 @@ bfa_ioc_get_adapter_optrom_ver(struct bfa_ioc *ioc, char *optrom_ver)
 static void
 bfa_ioc_get_adapter_manufacturer(struct bfa_ioc *ioc, char *manufacturer)
 {
-	strncpy(manufacturer, BFA_MFG_NAME, BFA_ADAPTER_MFG_NAME_LEN);
+	strscpy(manufacturer, BFA_MFG_NAME, sizeof(manufacturer));
 }
 
 static void

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231005-strncpy-drivers-net-ethernet-brocade-bna-bfa_ioc-c-68f13966f388

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